Tag Archives: Severe weather

Strongest NWS Hurricane Ever Recorded: Patricia (UPDATED)

October 23, 2015UncategorizedHurricane, Hurricane Patricia, Mexico, Severe weatherGreg Laden

Update, Saturday AM:

On Twitter, people are shocked and amazed that Hurricane Patricia turned into a tropical storm. Some had prayed to god and now claim those prayers were answered. There is at least one claim of a death on Twitter, but The Twitter Lies, and this is probably someone’s sick idea of a joke.

Naturally, what happened is Patricia made landfall as a very compact hurricane in a region with very few people, but as a strong category five hurricane. It had the highest sustained winds, and the lowest pressure ever observed for a hurricane, but again, Patricia was a small hurricane, not a monster. It was almost like Patricia was pretending to be a tornado.

And, since it came on quickly, and had some unusual characteristics, and was badly reported by almost all major media including the meteorological media, Patricia will now join cousins Sandy and Katrina in the ranks of the Most Misunderstood Hurricanes.

It is not over until it is over, and the storm is still moving across Mexico where it plans to hook up with a Gulf system and cross the border, Donald Trump be dammed, to hose Texas with major rains. In the mean time we’ll have to see what the storm does in the Mexican highlands. Watch the news reports.

Update, Friday PM:

We probably won’t know much until morning, but Hurricane Patricia’s eye has made landfall and the hurricane is falling apart.

This image from The Wundermap shows the last IR satellite image that clearly shows an eye just before it came ashore.

The part of the hurricane running from the eye to the right is where the strongest storm surge and strongest winds will be. You may have seen videos on the Weather Channel and CNN from Manzanillo, the nearest large settlement (see below for more details) but that is actually pretty far from the eye of this relatively compact storm. It looks pretty windy and rainy in those videos, but I’d be more worried about Costga Careyes, Emiliano Zapata, La Manzanilla, and San Patricio, especially anywhere where there are harbors or bays that might concentrate a storm surge. Here’s a rough drawing of where that eye is, and the zone to the right of the eye where the storm will pack the most punch:

Update, Friday PM

I updated the graphic above.

Odd point: I’m seeing news stories talking about the “giant size of hurricane Patricia.” Why is the press so dumb?

This is a very very strong, record breaking hurricane. It is not, however, giant.

And, Patricia is making landfall right about now, and for the next couple of hours. Remember what landfall is.

Power has been shut down in the area in anticipation of the power grid being affected by the storm.

Update, Friday early PM:

Nothing too new from the NWS but Jeff Masters has a lot of information on Patricia.

Patricia is not big, as in area covered, but has very low pressure and very fast winds. Depending on context, Patricia has broken or nearly broken a number of records, but this is all very complicated because some of the records are hard to pin down. For example, several hurricanes from the 50s and 60s had higher wind speeds than we have seen since, but we now know that the methods for measuring wind speed in a powerful hurricane were not adequate at the time, and most hurricane experts assume all those numbers are at least 10 mph or so too high. If that is the case, Patricia may have the fastest winds ever recorded. Patricia will end up bing in the top five (or should I say lowest five) in terms of pressure. Also, very few other hurricanes did something Patricia did: The storm turned from a tropical storm to a category five hurricane in less than 24 hours. That is just plain astonishing. Weather experts around the world are in shock.

Putting it another way, Patricia is doing some stuff we didn’t really think hurricanes do, even though a few have done here an there. This is a little like this year’s hurricanes globally; we are breaking records all the time in terms of numbers, size, strength, how many going at once, and all that. The combination of hurricane favoring conditions caused by global warming and the extra boost this year from El Nino is producing quite a bit of storm activity.

It does look like the general vicinity of Manzanillo is the most significant populated area near the most likely landfall. Hurricanes are bigger than cities, of course, and the details matter. In case you don’t know much about Manzanillo, here’s some information from Wikipedia:

Manzanillo is a city, seat of Manzanillo Municipality, in the Mexican state of Colima. The city, located on the Pacific Ocean, contains Mexico’s busiest port that is responsible for handling Pacific cargo for the Mexico City area. It is the largest producing municipality for the business sector and tourism in the state of Colima.

The city is known as the “Sailfish Capital of the World”. [1] Since 1957, it has hosted important national and international fishing competitions, such as the Dorsey Tournament, making it a very attractive fishing destination.[2] Manzanillo has become one of the country’s most important tourist resorts, and its excellent hotels and restaurants continue to meet the demands of both national and international tourism.

The main part of the storm is coming ashore now, as seen in this satellite image:

Videos and twitter reports from Manzanillo indicate strong winds and heavy rain.

Update, Friday Mid Morning:

The National Weather Service thinks Patricia will make landfall in around 12 hours, but tropical strength conditions are already developing on the coast.

Paul Douglas told me that this is the fastest he’s ever seen a hurricane develop.

The storm surge for this hurricane is expected to be very serious. If you look at the Mexican coast in this area, highlands start right after the coast and there are several small to medium size settlements sitting, in some cases, along small embayments. The worst case scenario is that the hurricane does in fact strengthen, as expected, and the right front punch of the storm aims directly into one of these embayments, flooding the settled area.

The NWS is saying this morning that “Residents in low-lying areas near the coast in the hurricane warning area should evacuate immediately, since the storm surge could be catastrophic near and to the east of where the center makes landfall.”

Sustained winds will be about 200 mph, with gusts of 250 mph.

Coastal and off shore waves will be very high (this is aside from the storm surge).

The dome of water being brought to shore by the storm ranges from 15-25 feet in height, and this could be concentrated in some areas by terrain. The most likely ground zero for a major storm surge may be the vicinity of Manzanillo. It is recommended that areas below about 20 feet elevation be totally evacuated, as there is the possibility of total destruction in those areas. But this “ground zero” could move.

The graphic above shows the most likely are of landfall, but watch this closely because the track could move. The most likely direction of a shift is probably to the north.

Once the storm lurches inland, it will dissipate quickly and turn into a big wet thing, that will drop a LOT of rain in hilly or mountainous areas. The highest death tolls from hurricanes tend to come from flooding inland, and with this sort of terrain, serious inland flooding and significant landslides are inevitable.

After the storm “dissipates” it is likely to join up with a cyclonic system forming in the Gulf. This will cause a major storm in the northwestern Gulf of Mexico. Parts of Texas and Louisiana could get a foot of rain or more, with further significant rain across a much larger region including Oklahoma and Arkansas, starting over the weekend and into early next week.

Original Post:

Holy cow, man. Patricia, an Eastern Pacific Hurricane, became what is probably the strongest hurricane ever recorded by the National Weather Service in the NWS Hurricane Center’s area of responsibility (AOR), which consists of the Atlantic and the Eastern Pacific.

The storm is heading straight for Mexico. This is serious.

There are various ways to measure hurricanes. Maximum wind speed, central pressure (lower is badder), overall size (of hurricane force wind field), and overall total strength (using one of a couple of different metrics). Although weather forecasters and normal people tend to focus on wind speed hurricane experts are more impressed with central pressure. These things are all related, of course. But Patricia is the strongest hurricane with respect to its central pressure, and winds.

From the NWS:

Data from three center fixes by the Hurricane Hunters indicate that the intensity, based on a blend of 700 mb-flight level and SFMR-observed surface winds, is near 175 kt. This makes Patricia the strongest hurricane on record in the National Hurricane Center’s area of responsibility (AOR) which includes the Atlantic and the eastern North Pacific basins. The minimum central pressure estimated from the aircraft data, 880 mb, is the lowest ever for our AOR. It seems incredible that even more strengthening could occur before landfall later today, but recent microwave imagery shows hints of a concentric eyewall developing. If the trend toward an eyewall replacement continues, it would cause the intensity to at least level off later today. The official forecast shows only a little more strengthening before landfall. Given the very mountainous terrain that Patricia should encounter after landfall, the cyclone should weaken even faster over land than predicted by the normal inland decay rate.

The storm will hit Mexico as a strong category 5, the kind of category 5 that makers you wonder why there is not a cateory 6, TODAY (Friday). Incredibly, the storm is expected to get STRONGER before that happens. Winds will reach 200 miles per hour before landfall.

Huge coastal waves, a huge storm surge, intensive inland flooding are expected. This is a catastrophe unfolding.

Stormy Weather and Climate Change This Week

October 9, 2015Uncategorized2015, Climate Change, Climate Change, Global Warming, Global Warming, Hurricane, hurricanes, severe weather, Severe weatherGreg Laden

South Carolina Floods

I haven’t said much about this partly because there is so much good coverage, but South Carolina’s floods, still ongoing, are going to get on the list of worst weather events of 2015. Since these floods are amounting to a one in 1,000 year event, they are actually on the list of worst weather events since Vladimir the Great died, Cnut the Great invaded Enlgand (unrelated event), Eric Haakonsson outlaws berzerkers in Norway, and Olaf Haraldson declared himself King of Norway.

And yes, that event was climate change enhanced in at least two ways, maybe three. With global warming there is more moisture in the atmosphere and in large parts of North America it seems that this moisture is often clumped up into longer term slow moving rain systems. That was going on in the region for days. Then, the strength, size, and wetness of hurricane Joaquin, which indirectly fed moisture into the system, was enhanced by very high sea surface temperatures in the Atlantic. Also, those sea surface temperatures have generally increased the punch from Atlantic based storms. All in all, it is likely that South Carolina, the neighbor of the state that is famous for making climate change illegal, and who’s congressional delegation refused to help the victims of Super Storm Sandy, got walloped by climate change.

Fortunately for the good people of South Carolina, our federal government does not act cynically and help is on the way. But next time we are called to help a storm impacted region, we expect South Carolina to put their big kid pants on and step up to the plate.

Oh No, Oho!

The storm formerly known as Oho, a Category 2 eastern Pacific hurricane, is in the process of doing something that does not happen very often: Slamming into British Columbia and Alaska. I’m told this is only the second time a tropical storm, in a post-tropical state, has followed a track like this.

Probably not a big deal for a region where serious windy and wet storms are common. But this is yet another case of the tropics breaking out of their usual pattern as a result, likely, of climate change combined with this year’s ongoing El Nino. Certainly, warm sea surface temperatures (which are everywhere there is sea) have helped this system maintain strength as it has moved north.

Here in Minnesota, famous for winters that start in October, we will be experiencing a summer like weekend. Global warming plus El Nino has exacerbated an ongoing trend of warming falls. Too bad some of our garden plants respond more to changes in sunlight than to changes in temperature, or we might not be eating fried green tomatoes for dinner tonight.

More hurricanes to come?

Meanwhile keep an eye on the Eastern Pacific. Two more disturbances are developing with reasonable (though not certain) chances of becoming tropical storms. 18-E is very likely to become a hurricane by early Sunday morning, and if so it will be called Pali. Disturbance Number 1, just getting going, has about a 50% chance of becoming a tropical storm over the next five days. All quiet in the Atlantic, the rest of the Pacific, or the Indian Ocean.

In case you were wondering about the climate change – hurricane link, this might be of interest to you:

South Carolina Rain

October 4, 2015UncategorizedRain South Carolina, Severe weatherGreg Laden

This is from this morning National Weather Service:

MESOSCALE PRECIPITATION DISCUSSION 0550
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
413 AM EDT SUN OCT 04 2015

AREAS AFFECTED…NORTHEAST GA…SC…SOUTHEAST NC

CONCERNING…HEAVY RAINFALL…FLASH FLOODING LIKELY

VALID 040813Z – 041413Z

SUMMARY…HISTORIC RAINFALL EVENT CONTINUES ACROSS MUCH OF SOUTH
CAROLINA THIS MORNING WITH VERY HEAVY RAINFALL RATES EXPECTED.
WIDESPREAD AND SERIOUS FLASH FLOODING IS LIKELY TO REMAIN A
PROBLEM THROUGH 10 AM.

DISCUSSION…A HUGE MOISTURE PLUME FEEDING INTO THE NORTH SIDE OF
THE CLOSED UPPER LEVEL LOW OVER THE SOUTHEAST U.S. HAS MOVED VERY
LITTLE OVER THE PAST SEVERAL HOURS. TREMENDOUS MID AND UPPER
LEVEL DIVERGENCE WITHIN THIS PLUME IS ALLOWING FOR VIGOROUS ASCENT
IN AN ENVIRONMENT WITH 1.8 TO 2.3 INCH PW VALUES. SOME OF THIS
MOISTURE IS ORIGINATING FROM HURRICANE JOAQUIN. MUCAPE VALUES OF
1000-2000 J/KG NEAR THE SC COAST ARE HELPING TO FURTHER ENHANCE
RAINFALL RATES. A COASTAL FRONT NEAR THE SC/NC COAST REMAINS
NEARLY STATIONARY AND IS ACTING AS THE FOCUS FOR CONVECTION WITH
THE HIGHEST RAINFALL RATES. THE AXIS OF HEAVIEST PRECIPITATION
MAY PIVOT TOWARDS SOUTHEAST NORTH CAROLINA BORDER BY MID MORNING.

HI RES GUIDANCE INDICATES THAT LOCAL AMOUNTS OF 3-6″ ARE POSSIBLE
WITHIN THIS REGION OVER THE NEXT SIX HOURS, AND COULD FALL AT
RATES OF UP TO THREE INCHES PER HOUR AT TIMES. THESE TYPES OF
RAINFALL RATES ARE LIKELY TO CREATE SIGNIFICANT PROBLEMS IN URBAN
AREAS SUCH AS CHARLESTON, GREENVILLE/SPARTANBURG, COLUMBIA, AND
AUGUSTA. RADAR ESTIMATES HAVE BEEN RUNNING ABOUT 30 TO 50% TOO
LOW OVER THIS REGION OWING TO EFFICIENT RAINFALL PRODUCTION IN A
HIGH PW ENVIRONMENT. THE GROUND IS COMPLETELY SATURATED ACROSS
NORTHEAST GA AND MOST OF SC WHERE RAINFALL OVERNIGHT HAS BEEN
PERSISTENT. CONSIDERING THE RAINFALL EXPECTED, COMBINED WITH WHAT
HAS ALREADY FALLEN, MAJOR TO LOCALIZED CATASTROPHIC FLASH FLOODING
ALONG WITH POSSIBLE LANDSLIDES AND MUDSLIDES IN THE HIGHER
ELEVATIONS OF SC AND GA REMAIN AN ONGOING CONCERN.

HAMRICK

Hurricane Joaquin: Near Cat 5 On Way Out To Atlantic

September 28, 2015UncategorizedAtlantic Hurricane, Hurricane, Joaquin, Severe weatherGreg Laden

SEE ONGOING UPDATES BELOW FOR THE LATEST INFORMATION

Tropical Depression Eleven is currently located way east of Florida, and is predicted to become a tropical storm by Tuesday night some time. It would be nameD Joaquin. Some time Wednesday night, the storm is predicted to turn north and head straight up along the coast. There are no significant advisories or suggestions of a threatening situation from the National Weather Service, but it is always a good idea to keep an eye on these storms.

It was predicted that there would be about 12 named storms this season. There have been 9 so far, but we still have all of October and November. So this season is almost exactly on track. If it seems like a more anemic season than that, it is because several of the named storms died off far at sea.

Check this space for updates on Joaquin. Or not, if nothing interesting happens.

UPDATE Tuesday AM:

Eleven became Joaquin overnight.

The forecasts for what this storm will do are highly uncertain and seem to be divided into two different scenarios: Joaquin gets absorbed into an existing system along the US East coast, vs. Joaquin stays somewhat organized and travels up the Atlantic. The forecast currently settled on by the National Weather Service has Joaquin never forming into a hurricane but reaching top winds of about 65 MPH, but staying pretty far off shore.

UPDATE: Tuesday PM:

There is still all sorts of uncertainty about Joaquin, but it is not predicted that the storm once seemingly destine to be named but not a hurricane will likely become a hurricane pretty soon, and remain one all the way up the Atlantic, over the course of its current forecast. Click on the image to see it as an animated GIF:

UPDATE: Wednesday AM

Joaquin is now ~~predicted to become a hurricane some time later today (Wednesday)~~ classified as a hurricane. It will ~~then~~ now continue to move mostly west or west-southwest for a while then turn north.

This is when things get interesting. Depending on how far west the storm moves before turning north, and depending on other things, the hurricane will then move up the Atlantic well offshore and move out into the Great North Atlantic Hurricane Graveyard. Or, it will go north for a while, first getting stronger then getting weaker, before making left turn and hitting the US coast. The possible areas of landfall include the Chesapeake but other points as well.

In a way this is a battle between the Americans and the Europeans. The classic American hurricane models tend to show the storm striking the coast, while the European model tends to show the hurricane continuing harmlessly (unless you are a boat) into the Atlantic where it would dissipate.

In the past, according to Paul Douglas, my main source for these things, the European model has done a better job of predicting American hurricanes. (Obviously this is Obama’s fault, where’s Rush Limbaugh’s commentary on this?) But, the American models (and I’m simplifying the meaning of “American Models” here a bit) are not totally useless.

A pretty good prediction, which is based in large part on what the National Weather Service says, and what Paul and other meteorologists way, is that Joaquin will go west for a while, turn north, somewhere in there turning into a nearly but not quite Category 3 hurricane, quite possibly threatening the Bahamas, then move north fairly quickly as it weakens and makes a big wet spot in the North Atlantic.

Having said that, every update over the last couple of days has the storm becoming stronger, and the prospects of a landfall, while the lest likely scenario, have not really diminished. A land strike remains a plausible but less likely scenario. The place of landfall, should that happen, also remains highly uncertain, but it seems most likely that it would at or north of the Chesapeake. Even models that do not have landfall have lots of rain along the US coast (and inland a ways) so an important weather event is in the offing no matter what. From the Weather Underground:

Regardless of the ultimate outcome of Joaquin’s path, portions of the East Coast will still see multiple impacts from the evolving large-scale weather pattern, including flooding rainfall, gusty winds, high surf, beach erosion and some coastal flooding.

Paul Douglas provides this graphic of the many tracks produced by the many models:

One of the models, not the most likely one but possibly around a 20-35% chance, has the storm being somewhere around a Category 2 or Category 3 striking the area around the Chesapeake, like this (Also from Paul Douglas):

That would be as early as the weekend some time.

The prudent thing to do is to prepare for a land strike like this to the extent one might prepare days in advance, but to keep an eye on the forecast and stand down when it does not actually materialize.

Again, the National Weather Service is saying that the prediction of what the storm will do once it turns north depends a great deal on when it does so, because that influences the timing of the storm’s interaction with other weather systems. The turning may happen around Thursday mid day through evening. So, the forecast late on Thursday may be a much better estimate of the likelihood of a landfall.

UPDATE: Mid Day Wednesday

This is an important update.

The forecast for Hurricane Joaquin is still highly uncertain, but the National Weather Service has added an important new wrinkle (Number 2 below):

KEY MESSAGES:

1. Confidence in the details of the track forecast late in the
period remains low, since the environmental steering currents are
complex and the model guidance is inconsistent. A wide range of
outcomes is possible, from a direct impact of a major hurricane
along the U.S. east coast to a track of Joaquin out to sea away from
the coast. It is therefore way too soon to talk about specific
wind, rain, or surge impacts from Joaquin in the U.S.

2. Should the threat to the U.S. increase, any further adjustments
of the forecast to the west would likely be accompanied by an
increase in the forecast forward speed, with impacts along the coast
occurring sooner than currently forecast. A hurricane watch could
be required for portions of the U.S. coast as early as Thursday
evening.

3. Many areas of the eastern U.S. are currently experiencing heavy
rains and gusty winds associated with a frontal system. This
inclement weather is expected to continue over the next few days,
which could complicate preparations for Joaquin should it head
toward the coast.

The chances of a landfall in the US are still probably around one in five or so, but now the NWS is saying that IF Joaquin does ultimately make landfall (probably in the Chesapeake bay area) it will do so after having sped up quite a bit, and watches could be posted late tomorrow.

Also note that the eastern US is currently experiencing very rainy and windy weather, which may make preparation for the storm harder. Also, many rivers and creeks are already nearly flooding or flooding, so additional rain brought to a large area of the east coast (and by “coast” I mean large areas of any or all “east coast” states, not just along the Atlantic) will make that worse, even if the hurricane does not make landfall.

Jeff Masters has a writeup on the storm here.

UPDATE Tuesday Evening

Interestingly the divergence between the two disparate set of models, one showing the hurricane going out to sea, the other hitting land, has increased rather than decreased since mid day. Also, the most likely area of landfall, IF there is landfall, has moved south, to the Carolinas. Also, the updated forecast is quite different in the pattern of strengthening, perhaps strengthening more slowly but staying stronger longer. So, while I promised you increased clarity the NWS is actually less certain.

The following graphic compares two of the models, ECMWF and GPS (top and bottom, respectively) generated using the Wundermap, for the position of Hurricane Joaquin in the wee hours of the morning next Tuesday.

Both of these models can’t be true in the version of the universe we live in. Also, don’t make too much of the timing, the storm could move at a very different rate than projected once it starts speeding up.

Below is a projected path for the storm, but don’t put much value in this. It is the consensus between two widely divergent sets of models So this is a bit like arguing over eating Vegan vs going out to a Steakhouse, and deciding to compromise. There actually is no realistic combination of the two.

Regardless of all of this, the Bahamas is potentially in trouble. Apropos that,

CHANGES WITH THIS ADVISORY:

The Government of the Bahamas has issued a Hurricane Warning for
the Northwestern Bahamas including the Abacos, Berry Islands,
Eleuthera, Grand Bahama Island, and New Providence, but excluding
Andros Island and Bimini.

The Government of the Bahamas has issued a Tropical Storm Warning
for the Southeastern Bahamas, including the Acklins, Crooked Island,
Long Cay, the Inaguas, Mayaguana, and the Ragged Islands, but
excluding the Turks and Caicos Islands.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for…
* Central Bahamas including Cat Island, the Exumas, Long Island,
Rum Cay, and San Salvador
* Northwestern Bahamas including the Abacos, Berry Islands,
Eleuthera, Grand Bahama Island, and New Providence, but excluding
Andros Island and Bimini

A Hurricane Watch is in effect for…
* Bimini

A Tropical Storm Warning is in effect for…
* Southeastern Bahamas including the Acklins, Crooked Island,
Long Cay, the Inaguas, Mayaguana, and the Ragged Islands, but
excluding the Turks and Caicos Islands.

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. Preparations to protect life and
property should be rushed to completion.

A Hurricane Watch means that hurricane conditions are possible
within the watch area.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

For storm information specific to your area, please monitor
products issued by your national meteorological service.

UPDATE: Thursday AM: Dilemma

To be in a dilemma is to have the choice of which horn of the bull you prefer to be gored by. At the moment, there are many people facing a dilemma with respect to Hurricane Joaquin.

Pity the poor weather forecasters. If they say “Look out, this hurricane may strike land,” and the hurricane does not, they will be the Forecaster Who Cried Wolf, and in the future, many of those who were NOT hit by the hurricane will be less likely to pay attention to the forecasts. So forecasters can’t overplay the possibility of a landfall. On the other hand, if forecasters don’t jump up and down and shout a little, and there is a landfall, perhaps some of those who needed to be warned will have prepared less.

There is another dilemma of sorts. Over the last several years, the famous European Model has done a better job of forecasting hurricane position and strength than many other models. The European model forecast Super Storm Sandy pretty well, for example. This is a model that should be listened to. But for Hurricane Joaquin, the European model stands alone in forecasting that the hurricane will wanter out to sea and not make landfall as a significant storm anywhere. The other models all have the storm hitting something along the East coast.

These two sets of contrasts place people who might (or might not) be in the storm’s pat with various personal and domestic dilemmas about what to do and not do over the next few days by way of preparation or changes in plans.

There is another dichotomy of sorts as well. At this point it is fair to ask, as it is with any major weather event, how much of this meteorological problem is the result of anthropogenic global warming. For many (not me) the standard line is “you can never attribute a single weather event to global warming.” This, however, is incorrect for two reasons. The more subtle but more important reason is that many will read such a statement as “Weather events are not attributable to global warming,” which is wrong, and a dangerous proposition. The other reason it is wrong is that all weather is the short term function of climate, and the entire climate is changed by global warming. Weather (and climate) is made of heat, moisture, the movement of air, that sort of thing. Global warming has resulted in more heat, more moisture in the air, changes in the distribution of that heat and moisture at the global scale, and, apparently, changes in the nature of the movement of the air. There is not, in fact, a single weather event that escapes the influence of global warming.

In the case of Hurricane Joaquin, in particular, we have a fairly specific factor related to global warming in play. The sea surface temperature in the area where the storm is currently located, and the waters over which it will pass over the next day or two, are warmer than at any time in recorded history, making those seas warmer, likely, than they have been in many thousands of years. Tens, possibly hundreds, of thousands of years. This heat will cause Joaquin to read Category 3 or Category 4 status over the next couple of days. When a hurricane becomes that strong, it is harder for those factors that might weaken it to do so, so some of that extra strength plays through as the storm moves into extratropical regions. If Joaquin strikes land in the eastern United States while it is still a hurricane (as opposed to a weakened tropical storm) then we can fairly say that was a result of anthropogenic global warming.

So, is Joaquin going to hit something?

And if so, what will it hit?

We don’t know and we don’t know.

As noted, there is divergence among the models. The divergence has not reduced much over the last day or so, but in about 36 hours from now, it is likely that the models will converge and a much more accurate forecast can be made. At the moments, there are models that have the storm dissipate into the Caribbean (this is highly unlikely) and as noted the European model has the storm going out to sea. In between these projections there are scenarios where Joaquin makes landfall in the Carolinas, farther north in the Chesapeake, somewhere around New Jersey or New York, farther down-east in New England, or even eastern Canada. Within that rather broad framework, the storm could make landfall at any of a number of levels of strength, and do so at any of a number of speeds, but probably in all cases rather quickly. Quickly is not good, because it means that the storm can be affecting land areas as a stronger, not yet dissipated storm. On the other hand, slow is not good because the storm could pump more water into an already rain-soaked and flooding area. There really is no “good” scenario, just a variable number of different bad scenarios.

Here are a few graphics for what they are worth, which I’m afraid may not be much. They are cribbed variously from Weather Underground, Paul Douglas’s Blog, and the National Weather Service.

One generally reliable model (GFS) shows the storm menacing New England on or about October 7th:

The European model shows the storm out to sea on the same date:

The National Weather Service has settled, for now, on a forecast that has Joaquin strengthening to a Category 4 storm, then moving quickly north, transitioning through Categories 3, 2, and 1, grazing the coast and being somewhat ambiguous as to what it really ends up hitting.

In science, there is a rule known as the “Law of Parsimony.” This is usually mis-stated (in my opinion) as “the simplest solution is most likely to be correct.” In the case of multiple competing models, this could be though of as the average of the models.

But really, the Law of Parsimony means something different. It means, given a number of alternative explanations, the simplest one is the most likely to be least wrong. This, I’m afraid, is what the National Weather Service is forced to work with on this forecast. This graphic shows most of the known models on one map:

You can see that the NWS track, above, is a sort of average of all of these (it isn’t really, but many models are taken into account to produce the NWS forecast). But they are all so different from one another that any given track is highly unlikely to be wrong.

One pattern has emerged during the lifespan, so far, of Joaquin. Almost every one of the NWS forecasts has suggested a stronger storm than the previous forecast. Another pattern is that the level of uncertainty in the storm’s track has not gone down much, at least pertaining to the period of time after it makes a (very likely) turn to the north. After that turn happens, assuming it does, the forecasts should converge and we’ll now more.

When will that be?

In 12 to 24 hours from now. During the wee hours of the morning on Friday, or as late as mid day Friday, the storm will veer north and start to speed up. Probably. By two days from now, or about mid day on Saturday, the storm will be moving north very quickly, at about a Category 3 or Category 4 storm, and its subsequent direction will be much better understood. Whether or not the storm will make landfall in the US will be much more certain then. Probably.

However, given the direction and angle of approach, it will still likely be difficult to pinpoint an area of landfall even then. Also, and very importantly, look again at the graphic above. Look at all those sharp left turns, in contrast to the tracks that follow the coast more. Those would be two very different scenarios for this storm. An early sharp left turn could put a major hurricane in your home town, if you happen to live in just the right place. If, however, the storm tracks parallel to the coastline for a while, it could produce low-level havoc over a large area, and possibly come ashore as a big wet thing that is not a hurricane.

Which would you prefer? I know, right? Dilemma.

UPDATE: Thursday PM:

Just a quick update, I’ll have more later when there is both more information and I have a bit more time.

As expected, the diverse and disparate models have, according to the National Weather Service, started to converge on a narrow range of solutions. And, at the same time, the overall trend seems to be for Hurricane Joaquin to be likely to move farther from the coast than some models had earlier predicted. Here’s what the NWS says in their 5:00 discussion:

A strong majority of the forecast models are now in agreement on
a track farther away from the United States east coast. We are
becoming optimistic that the Carolinas and the mid-Atlantic states
will avoid the direct effects from Joaquin. However, we cannot yet
completely rule out direct impacts along on the east coast, and
residents there should continue to follow the progress of Joaquin
over the next couple of days.

Warning: I’ve already seen some reporters including possible meteorologists confuse the current heavy rains the Eastern states are experiencing with this hurricane. Many parts of the East Coast are flooding or will be flooding over the next few days, which has nothing to do with this hurricane. However, depending on exactly what Joaquin does, the hurricane may later contribute to this. So, if you were thinking you might be threatened with flooding, relatively good news about Joaquin moving out to sea does not apply to your situation at all.

And, of course, it is still too early to be totally confident in the model predictions. I would stick with what I said before: Tomorrow around mid day or early afternoon there should be fairly high confidence. Probably. We’ll see. Stay tuned.

UPDATE Friday AM:

Joaquin is fully into a turn to the north, is likely to strengthen more over the next several hours. But the various models have converged on a narrower set of likely outcomes. The NWS puts Tropical Wind Speed probabilities along the US coast or Eastern Canada at no better than 10 or 20%, and that applies only to far eastern New England.

I would keep watching this storm if you are in New Jersey or north, because it would not take much of a westward shift to change all this. Also, it is note entirely impossible (but unlikely) for the storm to make a sudden turn somewhere along the line. Such things have happened, though not usually without some indication in advance that it was at least possible.

UPDATE Friday PM:

Good news and bad news about Hurricane Joaquin.

The storm is still menacing the Bahamas and will do so for the net 24 hours, but it has now turned north and is likely to follow a path like this one:

That’s the good news.

The bad news is that Hurricane Joaquin is interacting with a major low pressure system in the eastern US to bring even more moisture to an already wet area. Jeff Masters has all the information on this. It is a pretty serious situation and needs to be paid attention to.

First, there is going to be “several days of coastal flooding and beach erosion” from “New Jersey to North Carolina” with especially heavy rain in North Carolina.

Second, in particular, “The latest 3-day Quantitative Precipitation Forecast from NOAA’s Weather Prediction Center is calling for 10 – 15″ inches of rain for the majority of South Carolina, including the cities of Charleston and Columbia.”

This is with Joaquin staying AWAY from the coast. If the hurricane ends up shifting towards the coast, things would change.

The rain will be due to what meteorologists call a “Predecessor Rain Event” (PRE) … In a Predecessor Rain Event, tropical moisture well out ahead of a landfalling tropical cyclone interacts with a surface front and upper-level trough to produce heavy rainfall, often with significant inland flooding. The PRE can develop well to the left or right of the eventual track of the tropical cyclone. Slow-moving Hurricane Joaquin is perfectly positioned to transport a strong low-level flow of super-moist tropical air that has water vapor evaporated from record-warm ocean waters north of the Bahamas westwards into the Southeast U.S. Once this moisture hits land, it will encounter a cut-off upper low pressure system aloft, with a surface front beneath it, which will lift the moist air, cooling it, and forcing epic amounts of rainfall to fall. The air will also be moving up in elevation from the coast to the Piedmont and Appalachians, which lifts the air and facilitates even more precipitation. Satellite imagery is already hinting at development of this connection of moisture between Joaquin and the Southeast low and frontal system.

Here’s what that looks like on the big scary map:

There are areas of the Carolinas that will experience one in 1,000+ year events during this period.

UPDATE Sunday Morning:

Joaquin is not heading out to the Atlantic for sure, but the outer bands will affect Bermuda. Also, the storm is passing close to Category 5 strength as it does so. Meanwhile, a special kind of interaction (noted above) is happening between the storm and the US east coast causing really bad rain and flooding mainly in South Carolina but in other areas as well.

The storm may have taken a cargo ship with over 30 people on it.

Erika Is A Remnant: UPDATED

August 26, 2015Uncategorizedhurricane, Hurricane, Severe weather, South Florida Miami, Tropical Storm ErikaGreg Laden

Saturday Mid Day UPDATE:

Erika is now an ex-tropical storm. A real hurricane has an eye. Erika is a cartoon dead eye (see graphic above).

When the Hurricane Prediction Center woke up this morning, they found Erika, ripped asunder by the rugged terrain of Hispaniola, to have “… degenerated into a trough of low pressure.”

The latest update from the NWS says, “this will be the last advisory on this system by the National
Hurricane Center unless regeneration occurs.”

Which gives me an idea. If Erika, this year’s Atlantic “E” storm, does regenerate into a named storm, it should take the next letter, “F” but instead of Fred they should use a more appropriate name for a reanimated storm. It should be Frankenstorm.

Friday Mid Day UPDATE:

Erika is changing, and the forecast is changing. The somewhat more likely scenario is now that Erika will not form into a hurricane at all, but remain as a tropical storm, and pass along the east side of the Florida peninsula, or in the eastern Gulf of Mexico, or possibly pass over land staying mostly in Florida. This is completely different than the most likely scenario late yesterday, which had Erika reaching hurricane strength near Florida, but staying in the Atlantic but with the possibility of menacing the Atlantic coast somewhere.

Here is the cone map for that scenario:

(Note also that the image at the top of the post is the most current NWS forecast.)

The alternative is that after Erika finishes its pass over Hispaniola it will strengthen and curve to the north sooner and remain in the Atlantic.

Should be an interesting 48 hours.

UPDATE:

(Latest map added to the top of the post, Thursday evening.)

First, I would like to note that there has been an odd reaction in various quarters to me posting on this storm. It is as though those who wish to deny the importance of climate and weather, and changes therein, would prefer we not speak of tropical storms. I wonder why.

The original point of discussing Erika here was two part. First, it is a tropical storm. I blog about them. Second, this particular storm had a somewhat unusual prediction of being a TS until about landfall in Florida, when it would quickly strengthen to a hurricane. That is historically interesting, but just as a coincidence, because ten years ago Katrina did the same thing. Otherwise, it is just an Atlantic tropical storm that will likely become a hurricane.

Meanwhile, five days turns into four, and we can make a better guess as to what the storm will do. Erika still has a chance as mentioned earlier of fizzling out over the next two days or so. But if the storms survives past that point there is a good chance it will develop into hurricane. But the original prediction of making landfall somewhere near, north of, Miami is changed, with the storm now more likely to curve northwards and not make a full on strike of the coast of Florida (though it may well affect the coast). After that, the storm may hug the Atlantic coast and maybe even make landfall somewhere, or curve even more and go up the Atlantic. After that, who knows?

This is the the updated track:

Still turning into a hurricane near Florida, but curving away from the coast.

Also, the 120 hour estimate had the storm reaching 75mph wind strength, and the current forecast has the storm becoming stronger in 120 hours (because the forecast moves forward with time, not a change in the nature of the storm).

Meanwhile, the storm is affecting the Leeward Islands. Flooding is occuring in Dominca. Weather Underground has this. As noted by Jeff Masters, the European Model is giving Erika the best chance of being strong, and near Florida.

I’ve looked at a handful of models and got some opinions of various experts, and most of the forecasts seem to show Erika staying in the Atlantic, but with a distinct possibility of making landfall somewhere. Florida is not out of the woods yet, North Carolina is a target in a handful of forecasts. A small number of models put Erika in the Gulf which puts it over some very warm water (and probably requires crossing the Florida Keys).

So, at this time, here is the basic question at hand. Which is more likely? Hurricane Erika forms and hits land, or Donald Trump gets the GOP nomination? At this point I’d bet on Trump but I would not take my eyes off of Erika.

Original Post:

On this ominous anniversary of Hurricane Katrina, we have the North Atlantic Hurricane Gods playing with our heads a little.

Here’s the thing. One of the effects of recent global warming is the overall increase in tropical storm activity, in all ocean basins, in recent years, and projected through the 21st century (see this for important research on this topic). Even so, due in part to effects of climate change in Africa and in the Pacific, and also (at present) El Nino, there has been notable attenuation of hurricane activity in the Atlantic Hurricane Basin. Generally, tropical storm activity has been rather impressive world wide over the last several years, and some of the tropical storms have done things that tropical storms don’t generally do, and those things are often likely attributable to global warming. For instance, Yolanda/Haiyan was extra strong, likely, because of extremely warm ocean waters at depth, rather than mainly near the surface. (Katrina was probably enhanced by this effect as well.) Obviously Sandy is an example. We have seen many days over the last couple of years with a very large number of Pacific storms existing simultaneously. We’ve seen tropical storms maintaining hurricane strength, or in some cases forming up, farther from the warmest equatorial regions than usual. And so on.

But, as noted, the Atlantic has mostly been relatively quiet, owing to a strong vertical wind shear and excessive Saharan dust, both predicted effects of climate change, but bad for hurricane formation. This year has been anemic as was last year, in the Atlantic.

(An important message here is this: If you live or have assets along the Gulf or the Atlantic, don’t become complacent!)

But now we have an interesting new storm that is doing two interesting things. The storm is Erika. The storm is heading towards the norther Lesser Antilles, and its effects may graze the northern regions of the Greater Antilles, as the storm track heads towards south Florida. The storm is predicted to remain as a tropical storm, not reaching hurricane strength, over this entire period. Then, the storm is (currently) predicted to make landfall in Florida, not far from Miami. The current track puts the storm’s center north of Miami (which would be good for Miami) but it is way to early to tell exactly where the storm will go.

So that’s one interesting thing: heading for Miami, which is a highly vulnerable population dense region in a red (thus denialist) state that has avoided a lot of tropical storm activity over many years.

The second interesting thing is that current models seem to have tropical storm Erika turning into Hurricane Erika just as it arrives in the Miami area. This is a Bizarro Storm if there ever was one. Instead of being a hurricane at sea and a tropical storm on land, it is, if the predictions hold, going to be a tropical storm (mainly) at sea and a hurricane (mainly) on land.

One of the things you may remember about Katrina is that Katrina hit south Florida as a tropical storm right on the border of hurricane strength, strengthened even as it made landfall, sauntered across the peninsula, entered the Gulf of Mexico where it weaved a bit, and turned north, turned into a powerful hurricane, and hit New Orleans. Like this:

Will Erika do this as well?

We don’t know. Or at least I don’t. There are meteorologists out there with models that they run way out in time. I remember hearing from the grapevine that Sandy was going to head north and hit somewhere around New York way before anyone was saying it publicly. Responsible meteorologist did not run around alarming people until they could be more sure. I’ve not even asked around about Erika.

The current path for Erika, as predicted, looks like this:

And up close (this is VERY far out so don’t use this to plan your evacuations or even your Hurricane parties) looks like this:

So somewhere between four and five days, “landfall” might occur near Miami, with currently predicted sustained winds at about 75mph.

It is clear that everyone in southern Florida (all across the peninsula, not just the Atlantic coast) needs to keep an eye on this, just for the heavy rainfall if nothing else. But things are very uncertain. The NWS is only issuing statements out to near the Bahamas at this point.

There is, of course, no such thing as ghosts. And there is no Hurricane God of the Atlantic. But Erika serves to remind us of Katrina, just in case anyone forgot (unlikely). And, Erika might be a serious storm, but will be interesting no matter what.

This from Eric Holthaus at Slate:

No place in America is more exposed than Miami, but amid a record-breaking lack of hurricanes in recent years, the booming city’s residents have grown complacent. Earlier this year President Obama traveled to the Everglades to highlight the region’s increasingly desperate battle to hold back the rising sea. Simply put, the region is overdue for a Big One.

Tropical Storm Erika is not that storm, yet. And the truth is, meteorologists won’t know how exactly powerful Erika could be for another day or two, at least.

Eric goes on to lay out his odds, very rough at five days out. Death in the Caribbean: 2 in 10. Weak landfall in Florida Panhandle, 2 in 10. Hurricane landfall in South Florida, 5 in 10. Worst case scenario (we shall not explore that here at this time): 1 in 10.

So, again, the binary message that I’m trying to stick to here. 1) This is something to pay attention to. 2) Five days is way to far into the future to say much. This storm could even totally fizzle out before hit hits Florida. Or not.

And to add a tri-nary to the binary, and to restate the original point of this post, Erika serves, because of its uncanny (but coincidental) similarity to baby Katrina, to remind us of that still unresolved disaster.

This might be a minor big deal. Or a bigger big deal. Only time will tell.

Hurricane Good News Bad News

August 7, 2015Uncategorizedhurricane, Hurricane, Severe weather, Soudelor, Tropical CycloneGreg Laden

First the bad news. Taiwan is going to get slammed with Typhoon Soudelor over the next day (landfall at about 8:00 AM local time). Soudelor was one of the strongest typhoons earlier during its development but weakened to a Category 1. However, very warm seas, lack of wind shear, and other factors may make Doudelor return to category 3 or even 4 strength before making landfall. Also, it is large.

The storm is likely to hit Taiwan in about the middle, which along the east coast is not heavily populated. But it will bring heavy rains, likely causing landslides and floods, to the mountainous middle of the island. On the other hand, the storm is moving quickly, so if it moves onto land and then moves through quickly, the total rain accumulation may be attenuated. After crossing Taiwan, the storm will hit mainland China.

Bob Henson at Weather Underground has a summary, but it is from yesterday.

Now the good news. NOAA has revised the estimate for the overall strength of the so far anemic Atlantic hurricane season, downgrading it a bit.

The NOAA Climate Prediction Center’s updated 2015 Atlantic Hurricane Season Outlook calls for a 90 percent chance of a below-normal hurricane season. A below-normal season is now even more likely than predicted in May, when the likelihood of a below-normal season was 70 percent.

This is largely due to increased vertical wind shear as a result of the strong El Niño we are experiencing. The agency is predicting between 6 and 10 named storms, with only 1-4 of them being hurricanes, with between zero and one being major hurricanes. So far the Atlantic has had three named storms, one of which managed to be hurricanes. A typical (average) season would have about 3 or 4 named storms (so this seems on track to be average) but by n ow on average one of the would be likely to be a hurricane. The El Niño related factors likely to attenuate a storm season are increasing and likely to maintain or increase over coming months.

Suddenly, The Atlantic. And Delores.

July 12, 2015UncategorizedHurricane, hurricane, Severe weather, Tropical Storm, TyphoonGreg Laden

But first a word bout Chan-Hom. That typhoon messed with China but not as badly as originally feared, because the storm turned to the east a bit. Now, Chan-Hom is heading for North Korea where it will come ashore as a wet tropical storm. I would not be surprised if more bad stuff happened there than with Chan-Hom’s glancing blow over the last 24 hours or so.

Now I’d like to direct your attention the Atlantic Ocean for a moment. Due to vertical wind shear and aridification-induced North African dust, we have been expecting that one effect of climate change would be that most (but not all) Atlantic Hurricane seasons would be attenuated. Add in El Niño and you get more of that attenuation. On the other hand, with Weather Weirding also associated with climate change, may be we’ll see more oddities than previously in the basin. This year, the Atlantic Hurricane season has been very anemic, maybe even more anemic than last year.

But suddenly, something might be happening and it might be a little odd.

Disturbance Number 1 is way far from the area where hurricanes normally form, and is classified as a non-tropical system. It is not likely to do anything. But it is sufficiently active that it got a mention by the National Weather Service and they are watching it closely.

Yes, folks, that’s all we’ve got in the Atlantic.

Meanwhile there have been many often quite active storms in the Pacific, including Chan-Hom of course, and now there is a named storm in the Eastern Pacific. It is Dolores (see image above). Delores is likely to turn into a hurricane some time tomorrow, and the storm will continue wet northwest out to sea, staying away from Mexico, through the work week. It is not going to become a very powerful hurricane (though all hurricanes are of course powerful) during that time. After that it all depends on how far north Delores drifts. The farther north, the more likely to weaken.

Meanwhile from the Weather Underground, we have this amazing graphic showing seven notable tropical energy blobs, including several named storms, some hurricanes.

Super Typhoon Chan-hom

July 9, 2015UncategorizedHurricane, hurricanes, Severe weather, Shanghai, Typhoon Chan-homGreg Laden

UPDATE: There are significant changes (as of Friday mid day Middle America Time) in the track and strength of the storm, mostly good news for china. See here for updates.

A large typhoon (hurricane) is heading for China and is expected to make landfall in the vicinity of Shanghai. The image above is from the Japan Meteorological agency, and the image below is from JAM via Jeff Masters Blog.

"Typhoon Chan-hom as seen by radar on Okinawa at 7:45 pm EDT Thursday (08:45 JST Friday, July 10), 2015. At the time, Chan-hom was a Category 4 storm with 130 mph winds." — “Typhoon Chan-hom as seen by radar on Okinawa at 7:45 pm EDT Thursday (08:45 JST Friday, July 10), 2015. At the time, Chan-hom was a Category 4 storm with 130 mph winds.”

Apparently Chan-hom will make landfall in a region that very rarely sees typhoons. Chan-hom will be, according to Masters,

… one of the strongest typhoons on record for a portion of the country unused to strong typhoons. Of particular concern is Chan-hom’s storm surge, which has the potential to bring the highest water levels ever observed into Shanghai, China’s most populous city, with 23 million people in the metro area.

This is all going to happen Saturday US time, in the wee hours of the morning, but PM locally. The storm, now a category 4, will likely be a category 2 at the time of landfall, which is still a problem.

The region has real tides, so a storm surge of several feet during low tide may be not such a big deal, while a storm surge on top of high tide could be devastating. In 1956 a storm came through with a nearly 6 foot storm surge but the normally 7+ foot tide was not high. In 1997, Winnie, a mere Category 1, struck near Shanghai. According to Jeff Masters,

the storm surge from Winnie was only 5.5″ (14 cm) below the top of the 19.2-foot (5.86 meter) Suzhou Creek floodgate that protects downtown Shanghai on the Huangpu River, which flows through the center of town. This floodwall was rated to protect against a 1-in-200 year flood, and was overtopped by about one foot (30 cm) along a 8.5 mile (13.7 km) section inland from the downtown area, flooding over 400 homes

The tied, therefore, will make a huge difference, and it is probably too early to say much about the co-occurrence of high tide and Chan-hom’s landfall.

Jeff has a LOT more on this storm and several related issues such as sea level rise in the area at his post.

Atlantic Hurricanes 2015: Will Bill? UPDATED

June 14, 2015UncategorizedAtlantic Hurricane, Bill, Hurricane, Severe weatherGreg Laden

There is an 80% chance that a disturbance in the Gulf of Mexico will become a tropical cyclone, a named storm, over the next couple of days. If that happens it will be called Bill.

Possible Bill is not well defined and is poorly organized. The disturbance is currently near the Yucatan, and will move northwestward over the next couple of days where it may pick up enough energy and be left sufficiently alone to crank up. The most likely coastal area to be affected are along Texas and parts of Louisiana. Even if the disturbance does not turn into a named storm, that region will likely experience significant rain. Here is an animated GIF of the satellite imagery of the area:

UPDATE 15 June 1:20 Central:

From the NWS:

An Air Force Reserve Unit Hurricane Hunter aircraft investigated
the broad area of low pressure in the Gulf of Mexico this morning,
and found that the circulation was too poorly defined to qualify the
system as a tropical cyclone. However, thunderstorm activity
continues to become better organized this afternoon, and the low
will very likely become a tropical storm this afternoon or this
evening as it continues moving to the northwest.

My understanding is that this storm is highly unlikely to develop hurricane level organization and strength, but it does seem very likely to be a tropical storm. But no matter what it does, it is going to dump a lot of rain on Texas. And then, it will sweep in land and end up in Pennsylvania or someplace, dropping piles of rain along the way.

Does global warming destroy your house in a flood?

June 3, 2015UncategorizedClimate Change, Climate Change, flooding, Global Warming, Global Warming, Severe weather, weather whiplashGreg Laden

Joe and Mary built a house.

They built it on an old flood plain of a small river, though there’d not been a flood in years. This was a 500-year flood plain. Not a very floody flood plain at all.

The local zoning code required that for a new house at their location the bottom of the basement needed to be above a certain elevation, with fill brought in around the house to raise the surrounding landscape. But Joe’s uncle was on the zoning board, and it wasn’t that hard to get a variance. This saved them thousands of dollars, and they built the house without the raised foundation or the fill.

Over the previous fifty years much of the hilly wooded land up river from Joe and Mary’s house had been converted to agriculture. This changed the nature of the flow of rain across the land surface and into the groundwater. It caused the streams to rise more quickly when it rained, rather then slowly over several days fed by springs linked underground to the forest. Downstream, a century ago, engineers built a bridge for the new road, and they put the pilings closer than would be done in modern times. This caused flotsam from spring floodwaters to accumulate at the bridge, backing up water quite a good distance upstream. A large marsh that fed into the river, upstream from Joe and Mary’s house, normally flooded during high water, holding much of the excess. But about a decade ago, Joe’s uncle built a large housing development there, filling the marsh. There was controversy, and it was even covered in the local Pennysaver, but he got the variance. All these things would have made flooding near Joe and Mary’s house to be much worse than otherwise, but that never happened. The 500-year flood zone hadn’t had any 500-year floods in a long time, maybe 500 years.

Meanwhile, while the forest was being cleared, the road and its bridge built, the housing development constructed over the marsh, and Joe and Mary’s house erected, everybody was putting CO2, a greenhouse gas, into the atmosphere. By the last decade or so of the 20th century, there was significant global warming. The increase in global surface temperature was not even; The Arctic warmed more than the rest of the planet. This caused a change in the behavior of the polar jet stream. Instead of occasionally becoming curvy and kinky and slow moving, the jet stream started to do this all the time. Then these waves went “quasi resonant” meaning that the large curves and loops would sit in one place for a long time, weeks or months. Meanwhile the heated up atmosphere started to take on more water vapor. Air that was wet enough to rain in the old days held the vapor longer because of the warmth, but when the super saturated air let the water out in the form of rain or snow, there was a lot of it. Since the weather systems follow the jet stream, they slowed down and would hang around for a long time in one region, raining and raining and raining while elsewhere there would be short term droughts.

One day, at Joe and Mary’s house, it started to rain. It rained four or five inches in a week. The basement got wet. The tomatoes were overwatered, and their leaves cringed. Everybody’s shoes started to smell. The dark, cloudy, wet days produced a sense of ennui.

Then, on the eight day, it really rained. It rained four inches in one day. The groundwater had been saturated, the streams and the river were already high. The torrential rainstorm raised the river to the 100 year flood level. Then to the 500 year flood level. Then a few feet more. Joe’s uncle’s housing development flooded. The bridge with its jam of flotsam became a dam. The water flowed around Joe and Mary’s house, filling the first floor with three feet of dirty water. Snakes took refuge on their roof. Their car floated away.

Eventually the water receded and Joe and Mary’s home was a total loss. The insurance guy had come by to give them the good news. They would receive a full payout for replacement cost of the home. While they were chatting, the insurance guy noted that the flood was caused by the dam of tree branches and house parts down at the bridge. Joe remembered his uncle’s housing development, the controversy about the flood basin, and noted that may have been a problem. The insurance guy agreed. Mary said she had read about how replacing forest with corn fields made runoff worse, so the streams and rivers would flood more. Joe and the insurance guy nodded. Yes, yes, that was a factor too. Nobody mentioned the fact that Joe and Mary had failed to build their home to code, but they were thinking it. They didn’t mention it because, really, they would only have raised the whole house by about two and a half feet, and the flood was higher than that, so what did that matter?

A few days later Joe and Mary were down at the coffee shop to meet a contractor to talk about using their insurance money to build a new house. They were sitting with the contractor going over preliminary plans, but were distracted by two graduate students form the nearby university sitting at the table next to them. They were talking about the flooding. They were talking about how global warming, caused by that CO2 being released into the atmosphere all these years, had caused the flooding. They were talking about the amplification of warming in the Arctic, the jet streams getting curvy and slowing down, the quasi resonant waves and the extra moisture in the atmosphere.

The contractor became annoyed. He had heard about global warming and all that, everybody had. But he also knew that the last four winters were unusually cold and snowy. His cousin had bought a Tesla electric car a few months earlier, and his cousin was an annoying tree hugging hippie. And, he remembered, he had heard an actual climate scientist on the TV the other day saying something about global warming and storms. In fact, he remembered quite clearly what the scientist had said. And now he wanted to say it too.

The contractor turned to the two graduate students, and got their attention. “Couldn’t help overhear your conversation,” he said to them. “But you know, you can’t attribute a single flood, or other weather event, to global warming. This was just a flood.”

Global warming. Dancing backwards and in high heels for more than 20 years.*

Eastern Pacific Hurricane Season: Carlos tours the coast?

June 2, 2015UncategorizedHurricane, Hurricane Blanca, Severe weatherGreg Laden

Blanca is the second named tropical storm in the Eastern Pacific. I’m pretty sure Blanca was originally a disturbance with a low probability of becoming a named storm, but I may have missed something. Blanca is intensifying rapidly and will reach hurricane status shortly if it has not already, and will likely develop to become a major hurricane. The storm is heading towards the Baja, but may weaken before it hits anything big.

Meanwhile, the first named storm of the season, Andres, is still a hurricane. Over the next few days, Andres will make a sharp turn almost in place and weaken.

Nothing of note is happening in the Atlantic, though the season officially started yesterday. Not much is expected this year as El Nino is usually associated with attenuated tropical storm activity in the Atlantic basin.

Of course, “not much” can still include a major landfalling hurricane. Just not a whole bunch of them.

Update:

While Blanca is now a tropical storm in the Baja region, a new disturbance is forming as of June 8, which is highly likely to become a named storm by the end of the week. If that happens it will be called Carlos.

Here is embryonic Carlos:

UPDATE (June 10 2015): Tropical Depression Three E is likely to become Hurricane Carlos in about two days. It is going to do something a little odd, moving north as it forms into a hurricane, then staying off the coast of Mexico for a couple of days. While the eye may not make landfall, the hurricane itself may scrape the coast for a good long ways. Or, it could move farther from the coast. Or it could move closer to the coast. Kind of up in the air right now.

A fair number of storms do this, but most go off farther into the Pacific. (See the image at the top of the post.)

UPDATE June 14th PM

Carlos is back to being a tropical storm hugging the coast of Mexico. Carlos is likely to reach hurricane strength over the next several hours and will stay right off the coast for a couple of days then move inland and down grade to a messy rainy storm.

Ana is coming up the Atlantic

May 9, 2015Uncategorized2015 hurricane season, Fan Fiction, Film, Hurricane, Severe weather, Star Wars, The Recompense, Tropical Storm AnaGreg Laden

I remember joking with my friend Ana about how her name would be attached to the first named storm in the 2015 Atlantic Hurricane season. It turns out Ana is an exceptional individual. Both of them.

Ana Miller as Aisha Lefu in "The Recompense: A Star Wars Fan Film." — Ana Miller as Aisha Lefu in “The Recompense: A Star Wars Fan Film.”

Ana, my friend, is an actor and is currently engaged in a project I’ll be telling you more about later. But in the meantime, you can visit this page and find out about a new and very interesting Star Wars related crowd-funded production called The Recompense. Give them money.

Meanwhile, back in the Atlantic Ocean, Tropical Storm Ana has formed, nearly three weeks before the official start of the Atlantic Hurricane Season. A few days ago Ana was a disorganized disturbance (I’m talking about the storm here) and now Ana is a full on tropical storm tracking the very warm Gulf Stream. Winds are steady at 60 miles per hour, gusting to 70.

From the National Weather Service:

Deep convection has increased somewhat near the center of the storm, and SFMR observations from the Air Force Hurricane Hunters continue to support an intensity of 50 kt. Ana will be moving over the cooler waters to the northwest of the Gulf Stream later today, and water vapor imagery shows a belt of upper-level northerly flow advancing toward the tropical cyclone. The decreasing sea surface temperatures and increasing northerly shear should cause Ana to weaken as it nears the coast. The official intensity forecast is similar to that from the previous package, and very close to the latest intensity model consensus, IVCN.

Tropical Storm Ana, the first storm of the Atlantic Hurricane Season.
The initial motion estimate is 320/3. The track forecast reasoning remains basically unchanged from the past few advisories. Global models continue to predict that the blocking mid-level ridge to the north of Ana will shift eastward and weaken over the next couple of days. These models also show a broad trough moving from the central to the eastern U.S. over the next 72 hours or so. This should result in the cyclone turning northward and north-northeastward with a gradual increase in forward speed. The official track forecast is similar to the previous one and in good agreement with the latest dynamical model consensus, TVCN.

Hey, good news, the NWS is implementing the long-ago announced policy of GETTING RID OF ALL CAPS!!1!! Meanwhile, Ana the Storm is expected to strike the coast of South Carolina, and/or North Carolina, tonight. The storm, once over land, will turn northeast and make its way back out to sea off Delmarva, and eventually menace, a little, southern New England. The middle of the storm will probably be crossing the Carolina coast about 8:00 AM Sunday, and what is left of it will be re-joining the coast and the Atlantic early Monday.

Drought in California and Climate Change: They are linked

March 23, 2015UncategorizedCalifornia Drought, Climate Change, Climate Change, Global Warming, Global Warming, Severe weatherGreg Laden

A paper just out now in PNAS by Noah Diffenbaugh, Daniel Swain, and Danielle Touma shows that “Anthropogenic warming has increased drought risk in California.” From the abstract:

… We find that although there has not been a substantial change in the probability of either negative or moderately negative precipitation anomalies in recent decades, the occurrence of drought years has been greater in the past two decades than in the preceding century. In addition, the probability that precipitation deficits co-occur with warm conditions and the probability that precipitation deficits produce drought have both increased. Climate model experiments with and without anthropogenic forcings reveal that human activities have increased the probability that dry precipitation years are also warm. Further, a large ensemble of climate model realizations reveals that additional global warming over the next few decades is very likely to create ?100% probability that any annual-scale dry period is also extremely warm. We therefore conclude that anthropogenic warming is increasing the probability of co-occurring warm–dry conditions like those that have created the acute human and ecosystem impacts associated with the “exceptional” 2012–2014 drought in California.

Michael Mann and Peter Gleick have written a commentary for PNAS to accompany that research. The graphic at the top of the post is from that study. They note:

California is experiencing extreme drought. Measured both by precipitation and by run- off in the Sacramento and San Joaquin river basins, 10 of the past 14 y have been below normal, and the past 3 y have been the driest and hottest in the full instrumental record. A plot of temperature and precipitation anom- alies over the full instrumental record from 1895 through November 2014 shows that the 3-y period ending in 2014 was by far the hottest and driest on record (Fig. 1). As of the publication of this commentary, the state appears headed into a fourth consec- utive year of water shortfall, leading to massive groundwater overdraft, cutbacks to farmers, reductions in hydroelectricity gen- eration, and a range of voluntary and man- datory urban water restrictions.

A number of studies have examined the California drought to try to determine if it was “caused by” (or otherwise affected by) human greenhouse gas pollution. These studies vary in their level of attribution, but increasingly it is becoming clear that anthropogenic global warming has a very big hand in this.

Mann and Gleick tackle the problem of defining drought. There are multiple ways to do so, and they relate to different causes. The plethora of definitions and relevant variables allows for a given study to miss any global warming effect by picking certain factors and ignoring others. Studies that look mainly at inputs to the hydrological system (i.e., rainfall) tend to miss the output part of the equation, including evaporation, which is exacerbated by a warming climate. Mann and Gleick point out that the Diffenbaugh study adds significant weight to the idea that anthropogenic climate change has increased the frequency, magnitude, and duration of California’s droughts. Perhaps more importantly, the Diffenbaugh study suggests “the emergence of a climatic regime in which all future dry years coincide with warmer conditions.”

Gleick told me, “The scientific evidence showing the growing influence of climate changes on extreme events around the world, including the ongoing California drought, continues to pile up. The clearest piece of this is the record high, and increasing, temperatures, which directly influence the availability and demand for water, but there is also growing evidence that climate change is influencing pressure dynamics and atmospheric circulation patterns that either bring, or divert, water from the west coast of the United States.”

So, the current drought in California is linked to human induced climate change, and in the future, this will be a more common phenomenon than it has in the base, according to the best available science. But what about other effects of climate change? I asked Michael Mann about the relationship between California Drought and his recent study showing that we should soon be entering a period (over the next couple of decades) during which heat that has been hiding in the oceans will be leaving it’s watery milieu and joining us up here on the surface. He told me, “Here is the linkage I think is most relevant: the “faux pause”, in our recent study, was closely tied to the predominance of La Nina-like conditions in the tropical Pacific for a large part of the past decade, and these same conditions are closely linked with California drought (La Nina years tend to be drought years in California, while El Nino years tend to be wet years—though this doesn’t necessarily hold true for every single event). So one might imagine that a return to a greater tendency for El Nino-like conditions in the tropical Pacific over the next decade or two (which would spell an end to the “Faux Pause”) could actually be a mitigating effect as far as California drought is concerned. A bit counter-intuitive, but that’s best assessment here.”

AGW Class Cyclone Pam Nearing Vanuatu

March 12, 2015UncategorizedGlobal Warming, hurricanes, Severe weather, severe weather, storms, Tropical Cyclone PamGreg Laden

Pam is a tropical cyclone of category 5 strength, but is churning over waters that have high temperatures at depth, a phenomenon we seem to be seeing more often lately, as a result of anthropogenic global warming. That is why I call it “AGW Class.” Strong Category 5, deep heat enhanced. It is said that this is one of only 10 Category 5 storms recorded in the basin since good data are available. The Weather Underground has the story.

In addition, there are three other tropical cyclones extant in the Pacific.

Nathan is just on the Tropical Storm-Hurricane boundary and is heading for Cape York, Australia. Olwyn is a fully formed tropical cyclone (hurricane) with sustained winds at 85mph, and is busy menacing the west coast of Australia, which it will scrape over the next several hours, reaching Sharks Bay very soon and passing off the southwest corner of OZ over the weekend. But since that is so many time zones away we really have no idea when any of this will happen. Bavi is a tropical storm out in the Pacific heading roughly west by northwest. This storm may reach hurricane strength in a few day, but the forecast I saw is very uncertain.

And yes, there are views of the Earth that allow you to see all four storms at once. Here is one from the Climate Reanalyzer. The storms are marked but you should be able to spot them:

This one, that I got of Twitter, has the storms marked:

You don’t see this every day.

New Study On How Global Warming Changes The Weather

March 12, 2015UncategorizedArctic Amplification, Climate Change, Climate Change, Global Warming, Global Warming, severe weather, Severe weatherGreg Laden

Human caused greenhouse gas pollution has warmed the planet. Global warming means more extreme weather. Many meteorologist who watch the weather every day see this. More and more research shows that greenhouse gas pollution changes the weather in a way that causes even more change in the weather. Changing weather systems means more lightning, increased high precipitation events in certain regions like the US Northeast, including more frequent large snow storms.

Global warming has had uneven effects. The Arctic has warmed relatively more than most of the rest of the planet. The major movements of air masses are driven by a combination of the rotation of the Earth and the movement of extra heat from the Equator towards the poles, a process that sets up the trade winds and the jet stream. But the additional warming in the Arctic has changed this pattern measurably, resulting in these and other changes in weather patterns.

A new study out in Science, by Dim Coumou, Jascha Lehmann, and Johanna Beckmann, “The weakening summer circulation in the Northern Hemisphere mid-latitudes,” demonstrates that storm activity in much of the Northern Hemisphere has changed in a way that matters to our weather, and is likely to change more in the future. From the abstract:

Rapid warming in the Arctic could influence mid-latitude circulation by reducing the poleward temperature gradient. The largest changes are generally expected in autumn or winter but whether significant changes have occurred is debated. Here we report significant weakening of summer circulation detected in three key dynamical quantities: (1) the zonal-mean zonal wind, (2) the eddy kinetic energy (EKE) and (3) the amplitude of fast-moving Rossby waves. Weakening of the zonal wind is explained by a reduction in poleward temperature gradient. Changes in Rossby waves and EKE are consistent with regression analyses of climate model projections and changes over the seasonal cycle. Monthly heat extremes are associated with low EKE and thus the observed weakening might have contributed to more persistent heat waves in recent summers.

The study has been written up by Chris Mooney, in the Washington Post, and Roz Pidcock at Carbon Brief. From the study’s press release,

“When the great air streams in the sky above us get disturbed by climate change, this can have severe effects on the ground,” says lead-author Dim Coumou. “While you might expect reduced storm activity to be something good, it turns out that this reduction leads to a greater persistence of weather systems in the Northern hemisphere mid-latitudes. In summer, storms transport moist and cool air from the oceans to the continents bringing relief after periods of oppressive heat. Slack periods, in contrast, make warm weather conditions endure, resulting in the buildup of heat and drought.”

“Unabated climate change will probably further weaken summer circulation patterns which could thus aggravate the risk of heat waves,” says co-author Jascha Lehmann “Climate simulations for the next decades, the CMIP5, remarkably show the same link that we found in observations. So the warm temperature extremes we’ve experienced in recent years might be only a beginning.”