Tag Archives: hurricane

Hurricane Matthew: The Scary Clown of Hurricanes!

September 27, 2016UncategorizedClimate Change, Global Warming, hurricane, Hurricane, Matthew, Sever Weather, Severe weather, Tropical StormGreg Laden

LATEST UPDATE IS HERE. CLICK HERE FOR LATEST UPDATE.

Update: Wed Mid Day

Matthew weakened, strengthened, strengthening

Matthew has interacted with land masses in Hispaniola and Cuba to the extent that the storm weakened quite a bit, losing its temporary Category 5 status.

But, now Matthew is already showing signs of strengthening, and is likely to grow back to Category 3 or 4 status as it moves over the Bahamas. How bad a hurricane is when it makes contact with land depends in large part on the angle of the attack, and Matthew will likely be affecting several spots in the Bahamas at a particularly bad angle.

Bahamas are in serious danger now

This is the current warning for the Bahamas:

At 200 PM EDT (1800 UTC), the eye of Hurricane Matthew was located
near latitude 22.1 North, longitude 75.3 West. Matthew is moving
toward the northwest near 12 mph (19 km/h), and this motion is
expected to continue during the next 24 to 48 hours. On this track,
Matthew will be moving across the Bahamas today and tomorrow, and is
expected to be very near the east coast of Florida by Thursday
evening.

Maximum sustained winds are near 120 mph (195 km/h) with higher
gusts. Matthew is a category 3 hurricane on the Saffir-Simpson
Hurricane Wind Scale. Some strengthening is forecast during the
next couple of days, and Matthew is expected to remain at category 3
or stronger while it moves through the Bahamas and approaches the
east coast of Florida.

Rainfall in the Bahamas is likely to be 8-12 inches wiht up to 15 in isolated areas.

A huge risk in this area is overtopping land masses with what may be a 10 foot storm surge. There may be large areas where fresh water, and fresh water plant communities, are destroyed, and may be affected for months or years to come, depending on exactly how this plays out. Nassau, the largest settlement in the area, is facing away from the storm’s track, so it will probably be spared a serious storm surge.

Florida is most likely to be affected in the US

Matthew, as a Category 3 or Category 4 will be getting close to Florida during the day on Friday. Depending on exactly what the storm does, it may spend enough time over extra warm waters of the Gulf Stream where it may strengthen. The storm may or may not make landfall in Florida. If the storm does not technically make landfall, there is still a very high probability of serious effects on the coast, most likely near central Florida.

NOTE: This is a perfectly good storm to display stupidity about landfall. Please avoid doing that.

Matthew is the scary clown of hurricanes

Then comes the strange part. Jeff Masters of the Wunderblog writes:

Thanks to my advancing years and a low-stress lifestyle that features daily meditation, there’s not much that can move me to profanity—except the occasional low-skill driver who endangers my life on the road. But this morning while looking at the latest weather model runs, multiple very bad words escaped my lips. I’ve been a meteorologist for 35 years, and am not easily startled by a fresh set of model results: situations in 2005 and 1992 are the only ones that come to mind. However, this morning’s depiction by our top models—the GFS, European, and UKMET—of Matthew missing getting picked up by the trough to its north this weekend and looping back to potentially punish The Bahamas and Florida next week was worthy of profuse profanity. While a loop back towards Florida and The Bahamas next week is not yet a sure thing, the increasing trend of our top models in that direction is a strong indication that Matthew will be around for a very long time. Long-range forecasts of wind shear are not very reliable, but this morning’s wind shear forecast from the 00Z run of the European model does show a low to moderate shear environment over the Bahamas and waters surrounding South Florida late next week, potentially supportive of a hurricane–if Matthew survives the high wind shear of 50+ knots expected to affect the storm early next week. The bottom line is that it currently appears that Matthew will not recurve out to sea early next week, and The Bahamas and Florida may have to deal with the storm again next week.

At this partiuclar moment, the red line in this graphic is the best guess for what may happen:

There is a version of this where Matthew crosses Florida and ends up in the Gulf.

This scenario probably involves Matthew experiencing a lot of wind shear starting around the time it is near Florida and points north, and out at sea. This may actually make the storm a Category 1 hurricane or even weaker. But, if it makes this loop, the storm will be ina position to reform as a hurricane and menace the coast again.

I wrote a piece of fiction in which a hurricane in this general area finds a loop like this, but never stops. It just keeps going and going. In that story, Florida is mostly inundated by sea level rise, so it is actually a somewhat different configuration, but the same idea. I wonder….

Final point for now: Do not take your eyes off this storm.

I’m posting Climate Signals causality widget for this storm here, hope it works for you!

Update: Tuesday AM

Hurricane Matthew May Be One Of The Worst Hurricanes Ever

Such things are typically in reference to the region. There will always be Pacific hurricanes that are bigger than Atlantic hurricanes. Etc. But Matthew may be, for many years, on the list of the top few Hurricanes in the Caribbean region, in terms of strength and damage. The storm also has a number of odd features, some of which seem to be associated with anthropogenic global warming.

Hurricane Matthew will almost certainly end up being one of the worst weather disasters of the decade. It may end up being the worst storm to affect the region around Jamaica, eastern Cuba, western Hispaniola, and the Bahamas, but especially the island of Hispaniola, where an unusual feature of this storm (see below) is causing extraordinary rainfall. Haiti is more clearly in the path of the storm, but the Dominican Republic could end up experiencing a serious disaster (see below). (See: Matthew Hits Haiti, Their Strongest Hurricane in 52 Years)

In the end, it is likely that Matthew will be a poster child for social justice and climate change, since the storm is global warming enhanced and is affecting one of the most vulnerable populations in the world, in an area that is also geographically vulnerable.

Matthew’s Mysterious Blob

Also, Matthew has a strange new feature. A “mysterious blob” formed within the storm several days ago. The blob is probably going to end up being one of those interesting weather patterns that Rush Limbaugh and Al Roker do battle over. It is a complicated and mysterious phenomenon perhaps never before recorded with modern instruments but anticipated by meteorologists in the textbooks.

Marshall Shepherd, of the University of Georgia (and former president of the American Meteorological Society) provides a discussion of the blob here. I’m not going to try to recreate his discussion here because it is very preliminary, but I note that Matthew is record breaking (nearly) in how far south if formed as a large storm. Matthew shouldn’t really have ever been born. But it was. And, the factors thought to be associated with Matthew’s Mysterious Blob might be more likely to occur in a south-forming hurricane.

The blob is basically a mini storm system, a small and quasi-independent tropical storm sort of, embedded within the larger hurricane. Like that birth mark that turns out to be your twin sibling. Maybe. Regardless of which metaphor works best, the blob could end up causing regions far to the east of the center of Matthew to experience rainfall of truly Biblical proportions. There are places on Hispaniola that may have rainfall amounts of well over three feet, and some wether stations near the blob have measured rainfall of well over 5 inches an hour. And, the storm is moving very slowly, so whatever the rainfall rate turns out to be at any given spot, it will add up to a large total, over rugged mud slide prone terrain occupied by under-built dwellings.

Matthew Is Global Warming Enhanced

Matthew is large, has a very low pressure core, very strong winds, and is moving slowly over waters that are, on the surface, warmer than normal because of global warming, which has contributed to the storm’s strength. The Atlantic is expected (and observed) to have more vertical wind shear as an effect of global warming, which should attenuate the formation or strengthening of most hurricanes in the region, but Matthew formed and grew large anyway, somewhat baffling meteorologists. Perhaps, in the end, extremely warm water will trump wind shear in the formation of disastrous storms.

Bob Henson wrote about this a few days ago:

Vertical wind shear of up to 20 knots has plagued Matthew for most of the last two days, yet the storm has not only maintained its structure but grown at a ferocious rate. Dissertations may be written on how this happened! Working in Matthew’s favor has been a steadily moistening atmosphere along its westward path, which means that the shearing winds didn’t push too much dry air into Matthew. Once it developed a central core, Matthew was able to fend off the wind shear much more effectively.

But wait, there’s more.

The waters in this region are also warmer at depth (100-200 meters or so?) because of global waring.

Again, Bob Henson:

…water temperatures are unusually warm throughout the Caribbean (and the entire western North Atlantic), with an area of high oceanic heat content directly beneath Matthew’s path. Such deep oceanic heat allows a storm to strengthen without churning up cooler waters from below that could blunt the intensification.

The degree to which the ocean is heated not just on the surface, is reflected in this graphic from NOAA:

The ocean below Matthew is not just warm on the surface, but warm at depth, and very warm at that.

A hurricane can maintain strength by moving fast over warm water. The storm itself cools the surface of the water by using that energy in its own formation, and by roiling the surface waters, causing mixing from cooler water below. So, underneath a typical hurricane may be regions where the water is not really warm enough to form or sustain a hurricane. So, running fast avoids that. One might expect a slow moving hurricane to damage itself by using up some of this heat and dispersing it to depth.

But, sometimes the water is at “hurricane warmth” (about 80 degrees F) for many tens of meters of depth. This allows the surface waters to contribute to the hurricane’s maintenance, enhancing the overall strength of the storm. Katrina did this in the Gulf of Mexico (though that story is a bit complex so be careful what you infer here) and Haiyan did it in the Pacific.

And now, Matthew is doing it in the Caribbean/Atlantic.

My strong impression is that this warming at depth is an effect of excessive sea surface temperatures, and is an effect of anthropogenic global warming. It will take the meteorological research community a few years to catch up to this idea, but your dollars and my donuts are on the table on this one, and I’ll be taking your money. This, if confirmed, could be thought of as a qualitative change in the nature of storms caused by global warming.

Matthew may be, in a sense, a representative of a new kind of tropical storm. We’ve been seeing a lot of outlier storms lately. This includes storms that form really fast, like Patricia. Matthew did that to some extent as well. Matthew may be defying the effects of wind shear. Like Katrina and Haiyan, Matthew is feeding off of deep warm water. And, Matthew has this mysterious blob thing. Sandy was an outlier as well, a major hurricane that maintained strength way far north, then ate a Nor’Easter and became a Super Storm. Matthew is heading along a track similar to the one that took Sandy north (not uncommon, nothing odd about that). We don’t know what will happen. But, if storms had real personalities (which they don’t but this is a blog post, not a peer reviewed paper) I would expect Matthew to be on the hunt for a Nor’Easter to eat!

Please note that Climate Signals (BETA) has a page up now on Matthew, exploring the climate change connection.

Matthew may hit the US.

And, of course, Matthew may hit the US coast. This has always been a possibility, but now the chances are increased, with more models suggesting that the storm will track farther west than the previous models (on balance) suggested, with several models suggesting a US coast landfall.

Where?

Take your pick:

That graphic is from here.

Though it is hard to see in that depiction, it seems most likely that Matthew will skip Florida, but probably still hose it down and make waves. The more likely landfall scenarios are anywhere from the Carolinas north.

This is a storm to watch very closely, and in which we shall remain in awe.

Older updates:

Update: Monday Mid Day

Matthew is a major hurricane, and is just starting to affect the area of eastern Cuba and western Haiti. Jamaica has already been affected and there are two or more dead there.

Starting about now and over the next 36 to 48 hours, both countries will likely be seriously affected by this storm. I suppose three countries, technically, given that the US has a bit of territory in the region as well. Various islands in the Bahamas are also likely to be very strongly affected.

This is a major hurricane, fairly large, very strong, and it will be spending enough time over very warm water to maintain its strength as a Category 4 hurricane, or nearly so, during this entire time.

Most but not all models put the hurricane to the east of Florida, but not too far, and later, it is possible that it will strike the US east coast. The average of all the models says no, it will stay at sea, but there is not much certainty behind that prediction.

Meanwhile, there is a another storm, which has somewhat ~~less than~~ better than a one in three chance of becoming Nicole, is quickly spinning up out in the Atlantic.

Matthew will be a news maker and a disaster for a lot of people. But they are brown and not Americans, so few will take notice and science deniers will continue to say that nothing has happened in the Atlantic in years. But, Matthew is something, and it is a bigger something than it otherwise would have been because of increased sea surface temperatures caused by anthropogenic global warming.

Update: Friday Mid Day

Matthew seems to have had, as a key characteristic, the capacity for very rapid change. What just became a hurricane about 24 hours ago is either now, or about to be, a Category 2 hurricane, and may well develop into something close to a Category 3 before hitting Cuba in a few days. The storm is expected to cross Cuba and perhaps stay as a hurricane the whole way, or to reform quickly, where it will heading north.

Vertical wind shear has been affecting the storm, which should be weakening it, but he weakening is not observed. Further wind shear is expected to slow rapid growth over the next day, but that may or may not happen. Then the shear lets up and strengthening begins. I have the sense that the predicted transition to ca 100 knot maximum sustained winds starting in about 24 hours is a bit conservative.

Some earlier models had this hurricane possibly crossing into the Gulf of Mexico, but now it seems that all the models are in aagreement on a course that will parallel the Florida Coast (possibly getting very lose to Florida, but probably not) then heading up the atlantic. (See graphic above, from Weather Underground.) Most of the models have Matthew staying out at sea, but a number have the storm coming ashore in any of several possible locations from North Carolina Through Buzzards Bay, Mass, or perhaps even farther north.

It is very likely that Matthew will have crossed Cuba and be north of the Island nation by around mid day next Wednesday, and it is certainly true that there will be a much better idea then as to where the storm will go next.

Update: Thursday Mid Day

The hurricane status of Matthew is so fresh that the NWS, at this moment, has a mixture of products that call it a tropical storm and products that call it a hurricane. To be a hurricane, a storm’s wind speed have to be 74 mph (64 knots) or more, and of course it has to be organized properly. The NWS Public Advisory and some of their graphical products call the storm a hurricane and the advisory indicates that maximum sustained winds are at 75 mph.

Interestingly, the “discussion” which is usually the best source of information, has the storm turning into a hurricane in several hours from now. I have gotten the impression all along that the strengthening of this storm has been a bit quicker than usual. This may be an example of that phenomenon.

The storm is expected to make landfall in a few days, as a hurricane, in Western Cuba, then head back out over the sea where it will likely strengthen owing to very warm waters.

It is hard to say what this storm will eventually do, but there is a non trivial chance that it will make landfall as a hurricane in the US, a better chance that it will stay out to sea but be close enough to the coast to be bothersome, and a very good chance that it will eventually wack into Canada or someplace as an extratropical storm. Very few models seem to suggest that Matthew will be one of those mid-Atlantic hurricanes that remains boring until it finally dissipates.

Update: Wed Evening:

Just a quick note to say that about a third of the forecast models suggest that Matthew could become a major hurricane, and a smaller number even suggest a category 5 hurricane.

Update: Wed PM:

Matthew has formed into a named storm, and continues to head westward across the Caribbean. This is a region sometimes called the “Hurricane Graveyard” because various effects tend to reduce the chance of hurricane strengthening, and increase the chance of weakening.

The storm is expected to upgrade to hurricane status by the end of the week, possibly late tomorrow. Later, it may make a right turn and head north toward Jamaica and eventually Cuba, or environs. Around the time the storm reaches Jamaica, it may be a Category 2 hurricane.

The chances of this storm, as a tropical storm or hurricane, striking or affecting the US coast is not insignificant. Keep an eye on it.

From Weather Underground, the “ensemble models” to give you an idea of what the computers are thinking:

Original Post:

The next named Atlantic storm will be Matthew. There is currently a well organized stormy blob in the Atlantic, heading for the Lesser Antilles, that has a very high probability of becoming a named storm, and that could happen by Wednesday or Thursday.

This seems to be a fairly fast developing storm. Also, though it is way to early to say much, its possible futures are interesting.

The storm could continue roughly westward and either encounter the Yucatan or western Cuba, then presumably on to the Gulf. But, it also seems very likely to make a hard right and squeeze between Cuba and Hispaniola, or perhaps traverse on e or the other, on the way to the Bhamas or Turkes and Caicos, then north into the Atlantic. This is not one of those storms with a near 100% probability of wandering out over the Atlantic until it dissipates. There is a reasonable chance that this could be a land falling storm in the US. Again, this is way too early to say but this is one to watch very closely.

Sea surface temperatures are plenty high in the waters over which this storm will track no matter which way it goes. Global warming enhanced anomalously hight. So, it is pretty much impossible for this storm to not be stronger than it otherwise would be owing to human caused global warming. Let us hope it doesn’t hit anything.

Hermine more serene?

September 3, 2016UncategorizedBarrier Beaches, Global Warming, Global Warming Enhanced Storm, Hermine, Hurricane, hurricane, severe weather, Severe weatherGreg Laden

Update (Sunday PM):

Hermine is still a big storm and will affect eastern regions to some degree, but the storm never reformed as a hurricane, and is not not expected to do so. Also, the storm has jinked out to the east more than expected and will likely move farther east. So, there will be some coastal effects, but not much out of the ordinary.

POST-TROPICAL CYCLONE HERMINE FORECAST/ADVISORY NUMBER 30
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092016
2100 UTC SUN SEP 04 2016

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY…

A TROPICAL STORM WARNING HAS BEEN ISSUED FROM WATCH HILL…RHODE
ISLAND EASTWARD TO SAGAMORE BEACH…MASSACHUSETTS INCLUDING BLOCK
ISLAND…MARTHA’S VINEYARD…AND NANTUCKET.

THE TROPICAL STORM WARNING HAS BEEN DISCONTINUED FROM FENWICK
ISLAND…DELAWARE SOUTHWARD…AND ALSO DISCONTINUED FOR DELAWARE
BAY NORTH OF SLAUGHTER BEACH.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT…

A TROPICAL STORM WARNING IS IN EFFECT FOR…
* NORTH OF FENWICK ISLAND TO SAGAMORE BEACH
* DELAWARE BAY SOUTH OF SLAUGHTER BEACH
* BLOCK ISLAND
* MARTHA’S VINEYARD
* NANTUCKET

Original Post:

Hermine was bad enough for florida, though of course, nothing like a Major Hurricane. But, the downgraded storm may not be done with us yet. There is a very good chance that Hermine will reform into a hurricane, or at least something that we’ll call a hurricane because it will look like a hurricane, blow like a hurricane, and hurt like a hurricane, over the next several hours. This will happen after the land-damaged storm passes over global warming heated ocean waters. Sometime between mid day and early evening on Saturday, Hermine could gain hurricane strength and directly affect New Jersey and nearby places.

Barrier islands from the Carolinas to New Jersey, but especially around Delmarva, New Jersey, and New York, are at risk for storm surges, with a major risk in southern Delmarva and Virginia Beach, and the lower Tidewater. Outer New Jersey may experience something like a 6 foot storm surge Sunday night or early Monday AM.

This is Labor Day Weekend. A very large number of people go to these areas over this Final Weekend before the perceived end of summer. Causeway roads that connect these barrier islands to the mainland may be washed out, and the barrier islands themselves are not great places to be.

The big question at hand is this: Will the state authorities in these areas have the will and the wiles to warn their citizens and visitors off these dangerous areas, or will they avoid damaging business by sitting on their hands. Then, either way — whether a particular area is damaged by the storm or damaged by safety in light of the storm — will there be some help for those businesses? Oh, and lets not forget to include these considerations in the costs of this storm.

So be careful, watch the weather, and pay attention, if you live anywhere on the US East Coast.

Super Typhoon Nepartak

July 7, 2016UncategorizedClimate Change, Climate Change, Global Warming, Global Warming, Hurricane, hurricane, Nepartak, severe weather, Severe weather, Taiwan, TyphoonGreg Laden

This is a huge hurricane/typhoon heading quickly, and imminently, towards taiwan.

The storm itself is roughly as wide as the island nation is long, so very little will be left unaffected.

The storm is at the very high end of the range of storms in size, strength, etc. It is currently equivalent to a Category 5 hurricane. It may weaken a bit before landfall over the next few hours, but it may remain a Category 5.

Winds, huge waves and coastal flooding from storm surges will be a big problem with this storm, but the largest problem may be the incredibly high rainfall, with about one meter of rain (3 feet) predicted in some locations. This could cause unprecedented and major flooding.

Nepartak should be regarded as a global warming enhanced storm. The storm is made so large and strong because of extraordinarily high sea surface temperatures, which in turn is an effect of human caused global warming.

Locally, the Green Island and the Taiwanese city of Taitung City are on or very close to the expected storm track. If the storm tracks a bit south, expect very severe storm surges in Taitun city. Either way, there will be major rainfall in the river basins, and the valley ousee north of Taitung City, which has several settlements in it, seems likely to be at major risk.

Here is the most current (10:34 AM CT) map from Weather Underground showing the relationship between the storm and Taiwan.

Climate Signals has info on the storm, and does a good job at evaluating the likely relationship between the storm and human caused climate change.

On July 4 and 5, in just 24 hours, cyclone Nepartak intensified from a 70 mph storm to a Category 4 super typhoon with 150 mph winds, peaking with 1-minute sustained winds of 173 mph (150 knots) on July 6. Currently a Category 5 storm, Nepartak is forecast to strike Taiwan Thursday night, July 7, local time (midday Eastern time) before moving on to eastern China. The rapid intensification of Nepartak was driven by favorable climate conditions, including passage over unusually warm seas with some of the highest oceanic heat content readings observed in conjunction with a tropical cyclone. There is a documented increase in the intensity of the strongest storms in several ocean basins in recent decades, including the Pacific Northwest. And warming seas are offering more energy to passing storms. Extreme rainfall over Taiwan is expected to be intense, fueled in part by a warmer atmosphere, with total rainfall in some areas reaching well above 3 feet. The reach of Nepartak’s storm surge will be extended due to elevated sea levels driven up by global warming.

Jeff Masters is covering the storm here. He discusses the very rapid development of this storm:

Category 5 Super Typhoon Nepartak is steaming towards a Thursday landfall in Taiwan after putting on a phenomenal display of rapid intensification on Monday and Tuesday. Nepartak went from a tropical storm with 70 mph winds on Monday afternoon to a Category 4 super typhoon with 150 mph winds on Tuesday afternoon, in just 24 hours.

The 2016 Atlantic Hurricane Season

May 12, 2016Uncategorized2016 Atlantic Hurricane Season, Forecast, hurricane, Hurricane, Severe weather, severe weatherGreg Laden

This year’s Atlantic Hurricane season will be stronger, forecasts suggest, than that of the previous two years, and stronger than the average year.

The Atlantic Hurricane Seasons starts on June 1st. But, there was a hurricane that happened already, either late in last year’s season or very early in this year’s season, called Alex. That hurricane had to go somewhere, and I suppose the keepers of the records had already put their spreadsheet to bed when Alex came along on January 7th, so that storm gets counted as part of the season that will nominally start at the beginning of next month.

A lot of factors determine the number and strength (and path) of hurricanes in the Atlantic. One is sea surface temperatures. An El Niño in the Pacific tends to cause vertical wind shear, which attenuates hurricane formation. Saharan dust also reduces the chance of formation or strengthening of these storms. There may be an association with La Niña conditions and a stronger hurricane season.

A small number of agencies or groups put out their forecasts. Often, the forecasts are similar to each other, and typically they are reasonably accurate. One of the more famous groups comes out of Colorado State University and until his recent death, was led by Hurricane Expert William Gray. NOAA also puts out a forecast. The Earth System Science Center (ESSC) at Penn State has been issuing forecasts since 2007.

The following graphic shows the relationship between the median number of named storms predicted each year by those three sources and the actual number of named storms in the Atlantic.

The first thing I notice is that the total range of variation in the predictions per year is less than the total range of variation in actual numbers over several years, and that the predictions roughly track the actual number of storms. This indicates that something is working. But I also note that the actual number of storms is often outside the range of predictions. So, while the predictions, in terms of number of named storms, give a reasonable estimate of the overall severity of the hurricane season, it is hard to predict these storms accurately months or weeks before the season starts.

This year, we are coming off an El Niño, which added surface heat to the already warm tropical seas, which of course is a result of human caused global warming. Also, we are probably heading into a La Niña season. If you look at the chart, you’ll notice that the last two seasons were relatively weak in the Atlantic. Last season’s El Niño and, probably, Saharan dust the season before, probably contributed to this.

This year, however, the two plotted forecasts (NOAA and ESSC) suggest a stronger season. There are two other forecasts, not shown on this graph, that also suggest a stronger season.

The average number of named storms for a base period of 1981-2010 is 12.1, so this year is predicted to be above average. The record high number of named storms was 28, in 2005 a year that also produced the record number of full-on hurricanes (15) and major hurricanes (7). That was the year of Katrina, Rita and Wilma, which were very memorable. (2005 was the year they ran out of names, remember?)

The ESSC report has, naturally more detail. From that report (emphasis added):

ESSC scientist Michael E. Mann, alumnus Michael Kozar, and researcher Sonya K. Miller have released their seasonal prediction for the 2016 North Atlantic hurricane season, which officially starts on June 1st and runs through November 30th.

The prediction is for 18.9 +/- 4.4 total named tropical cyclones, which corresponds to a range between 14 and 24 storms with a best estimate of 19 named storms. This prediction was made using the statistical model of Kozar et al. (2012, see PDF here). This statistical model builds upon the past work of Sabbatelli and Mann (2007, see PDF here) by considering a larger number of climate predictors and including corrections for the historical undercount of events (see footnotes).

The assumptions behind this forecast are (a) the persistence of current North Atlantic Main Development Region (MDR) sea surface temperature (SST) anomalies (0.88 °C in late-April 2016 from NOAA’s Coral Reef Watch) throughout the 2016 hurricane season, (b) development of a La Niña (Niño3 anomaly of -1°C) in the equatorial Pacific during boreal Fall/Winter 2016-17 (Climate Prediction Center April 2016 ENSO Discussion), and (c) climatological mean conditions for the North Atlantic Oscillation in Fall/Winter 2016-17.

If no La Niña develops (Niño3 anomaly between +/- 0.5 °C), then the prediction will be lower: 16.1 +/- 4.0 storms (range of 12-20 storms with a best guess of 16).

Using an alternative model that uses “relative” MDR SST (MDR SST with the average tropical mean SST subtracted) in place of MDR SST yields a slightly lower prediction (11.4 +/- 3.4 total named storms). This alternative model also includes the development of a La Niña.

So, as you can see, if there is no La Niñ this fall, there may be fewer storms in the Atlantic.

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.

Hurricanes in the Eastern Pacific: 2015 UPDATE

May 26, 2015UncategorizedAndres, Eastern Pacific, hurricane, HurricaneGreg Laden

See below for update.

You may not have even noticed it, but hurricane season has officially started in the Eastern Pacific. That is because the official date of the start of season is May 15th, though the actual hurricanes rarely get the memo and start whenever they want, but usually after that date. Last year’s Eastern Pacific season was much ore active than usual. The average numbers for named storms, hurricanes, and major (above Cat III) hurricanes for this basin are 15.4, 7.6, and 3.2. Last year’s season was predicted to be pretty much average, but it turned out to be exceptional, with 22 named storms, 16 hurricanes, with 9 major. In addition, there were other notable features such as several storms forming early, two early storms reaching Cat 4 strength, and one storm being the strongest ever recorded in May in the region.

What about this year? The only prediction I’ve seen suggests a somewhat more than average season (19 named storms, 11 hurricanes, with 4 major). So far there are no named storms, but there is one disturbance that is likely enough to turn into one that I thought this would be a good moment to start paying attention, thus this post.

The stormy system is currently known as Disturbance #1, and it is sitting in the pacific south of Mexico. The National Weather Service calculatges a 20% chance of this disturbance becoming a tropical cyclone over the next 48 hours, but an 80% chance over the next 5 days.

If Disturbance #1 becomes a named storm, it will be christened “Andres,” a previously unused name.

Fewer hurricanes that form in the Eastern Pacific hit land than for most other basins, and they very rarely hit the US or Mexico.

UPDATE (27 May 1:51 Central)

Disturbance 1 is developing. The National Weather Service says this disturbance has an 80% chance of forming a tropical cyclone over the next 48 hours, and a 90% of doing so over the next five days. Again, it will be named Andres if it becomes a named storm. Here’s what the region looks like (The red X is Disturbance 1):

UPDATE (28 May 12.27 Central)

Andres is a named tropical storm.

Typhoon Hagupit (Ruby): Update and what you can do to help

December 5, 2014UncategorizedClimate and weather, hurricane, Hurricane, Philippines, severe weather, Severe weather, Typhoon Hagupit, UncategorizedGreg Laden

The outer reaches of Typhoon Hagupit are already affecting the target region in the Philippines. Hundreds of thousands of people have fled the areas most under the gun, but the potential for serious problems covers a very large area. The storm has gone through quite a few changes over the last couple of days, but is probably strengthening somewhat right now. No matter what happens, it is going to hit the Philippines as a very serious storm.

Jeff Masters has an update here.

This is the same area that was hit with Typhoon Haiyan last year. Haiyan was a bigger storm. But, Haiyan was also one of the biggest typhoons ever observed (I think people are still arguing over whether it was the biggest, second biggest, etc.). There is potential for very high storm surges, serious winds, very heavy rains (over two feet in some places) which could cause devastating mudslides and flooding.

When this sort of storm hits people often want to know what they can do to help. I’ve learned about a recent project that you may be interested in. This is by Direct Relief. As background, let’s look at a relatively objective source of information about Direct Relief, Wikipedia:

Direct Relief (formerly known as Direct Relief International) is a private humanitarian nonprofit organization based in Santa Barbara, California, with a mission to “improve the health and lives of people affected by poverty or emergency situations by mobilizing and providing essential medical resources needed for their care.”[1] Founded in 1948 by Estonian immigrant William D. Zimdin, the organization is headed by President and CEO Thomas Tighe and a 31-member Board of Directors.[5] Direct Relief has received a 100% fundraising efficiency rating by Forbes,[6] been ranked by the Chronicle of Philanthropy as California’s largest international relief organization,[7] and topped Charity Navigator’s 2014 list of “10 of the Best Charities Everyone’s Heard Of.[8]” Direct Relief is the first nonprofit organization in the United States to be designated by The National Association of Boards of Pharmacy (NABP) as a Verified-Accredited Wholesale Distributor licensed to distribute pharmaceutical medicines to all 50 U.S. States and Washington, D.C.[9]

So it is an experienced organization, gets the money you give it out into the field efficiently, and is secular. All things I’m sure you want to see in an organization you make a donation to.

But the Hagupit situation offers an additional opportunity because Direct Relief has a new project in the field there, which looks promising. I was planning on talking to someone at Direct Relief about it, to find out more, but I think he got stuck in a meeting at the UN or something, so we’ll probably talk later (and I’ll report on that to you). Meanwhile, check this out:

Direct Relief’s Emergency Response Team is monitoring Typhoon Hagupit (locally known as Ruby), as it approaches the Philippines. On its current trajectory, the typhoon is expected to make landfall in the Eastern Visayas in the next 72 hours and could affect 4.5 million people.

Direct Relief already has staff on the ground ready to respond in the event of a disaster and has reached out to local partners and health officials located in high-risk regions 5, 6, 7 and 8.

There are also three strategically pre-positioned typhoon modules ready to be rapidly utilized in the event of an emergency. These modules contain enough medicines and supplies supplies to treat 5,000 people for a month following a disaster.

Philippine authorities are currently in the process of evacuating vulnerable communities. Vice Mayor of Tacloban city, Jerry Yaokasin, stated that “we will now strictly enforce forced evacuation.” Yaokasin said that “we have no more excuses, we have gone through Yolanda, and to lose that many lives, it’s beyond our conscience already.”

Direct Relief’s staff on the ground will be maintaining contact with partners and monitoring the situation as it develops in the next 72 hours.

There are three things you will find at Direct Relief’s web site.

<li>First, there is <a href="http://www.directrelief.org/hpp/?extent=99.1924,-1.6963,144.8076,27.1137">a monitor of the storm's path</a>, an interactive googly mappy think which is very cool.</li>


<li>Second, there is more information about <a href="http://www.directrelief.org/2014/12/monitoring-typhoon-hagupit-approaches-philippines/">Direct Relief and the situation in the Philippines</a>; they have one of the better organized web sites for disaster relief non profits. </li>


<li>Third, and most importantly, <a href="https://secure2.convio.net/dri/site/Donation2?df_id=2105&2105.donation=form1&_ga=1.168290657.1168894472.1417733221">there is a way to donate money</a>. </li>

When donating, frankly, I’d suggest the “wherever it is needed most” or “disaster relief” options. They are already there, on the ground; they will be relieving people as it happens. I have a feeling they know best where to spend the money.

The Eye of the Storm, And The Storm

October 17, 2014UncategorizedEye of Hurricane, Gonzalo, hurricane, Hurricane, severe weather, Severe weatherGreg Laden

There has not been much hurricane activity in the Atlantic for a while now, so unsurprisingly the reporting is starting to slip again. This post goes out to all you reporters at CNN and Reuters and Yahoo and everywhere else. Imma give you an example of what you are doing wrong, then I’ll send you to a place to learn up on it.

A recent report noted that “hurricane force winds are now bearing down on Bermuda, and the storm is expected to arrive within hours” meaning the eye would arrive within hours (paraphrased). This is not what is happening. When there is a hurricane arriving at your location, and the “hurricane force winds” start, that’s the hurricane. Not some other thing. The eye of the storm is one part of the storm. The rest of the storm is big and when you have hurricane force winds form that big circle thingie you see in the weather reports, that is the hurricane. For that matter, the lesser winds that arrive sooner, that’s the hurricane too. It’s a big thing, that hurricane. And the whole thing is the hurricane.

What does “Hurricane Landfall” mean?

But… but…. but what about when they say that word, what is is, “landfall,” isn’t that the EYE of the hurricane, so isn’t that the hurricane?

No. Read this: Hurricane Landfall: What it is and don’t be stupid about it.

Atlantic Hurricane Season Teaser

June 28, 2014UncategorizedHurricane, hurricane, Severe weather, Tropical StormGreg Laden

There is a stormy thing in the Atlantic that may become a Tropical Storm. It is really just a blob right now, but there is a roughly even chance that over the next two to five days it will form a tropical storm.

No matter what, this blob will menace the US east coast, though it is way too early to say if this will be a big deal or not. It is not entirely clear which direction it will be moving in over the medium term. We will be keeping and eye on it.

The Amazing, Impressive, Powerful Amanda

May 26, 2014UncategorizedAmanda, El Nino, hurricane, Hurricane, severe weather, Severe weatherGreg Laden

Usually when I make a sentence like that it is about my wife, Amanda. But this time we’re talking about Hurricane Amanda, the first hurricane of the Eastern Pacific hurricane season.

Amanda reached maximum winds of 155 mph on or about 8:00 AM Pacific Daylight Time on Sunday morning. That make Amanda the strongest Eastern Pacific May Hurricane on record. There are usually very few hurricanes in the Eastern Pacific in May, and the few that occur happen late in the months. Here’s the historical distribution of Eastern Pacific hurricanes, form 1966-1996:

Amanda is the earliest on record Eastern Pacific Category 4 hurricane.

The hurricane date for the Eastern Pacific is not well organized and accessible (without working hard) as far as I can tell. Wikipedia is shamefully badly organized and out of date, and the NWS focuses much more on Atlantic hurricanes because they are far more likely to menace the US (though Eastern Pacific storms of course can end up in Hawaii, and occasionally hit the US West Coast … and one actually slammed into Texas!).

So I can’t say much more about Amanda. The extra intensity and early date is certainly related to enhanced sea surface temperatures in the region, but the relationship between that and the possible coming El Niño can not be established at this time. Putting this another way, we can ask the question, is the Eastern Pacific Hurricane Season going to be affected by El Niño, the answer is clearly: We’ll see.

Amanda has weakened since, and is expected to continue to weaken as she moves north and turns into a tropical storm.

Dare I say it? (TS #Melissa in the Atlantic…) UPDATED

November 17, 2013UncategorizedHurricane, hurricane, Severe weatherGreg Laden

Added:

The depression has spun up to form a tropical storm. It will probaqbly remain a storm as it works its way up the Atlantic Ocean avoiding land (though it seems to be aimed ultimately at Greenland). The storm is named Melissa.

Details here.

We have had a record breakingly anemic hurricane season in the North Atlantic this year. How anemic? If this year’s hurricane season was a rug, you’d have a floor. If this year’s hurricane season was a car you’d have a bicycle. If this year’s hurricane season was a stack of pancakes, you’d have one pancake. That’s now anemic.

What is the reason for this poor performance? First, let me point out that expectations were not that high to begin with. The most useful and heretofore accurate model for hurricane frequency had suggested a number of named storms that is pretty close to the actual number that occurred (though higher). Hurricane number varies a lot from year to year in all of the different ocean basins, because hurricanes are rare events to begin with. In fact, I’d even say they are unlikely events because so many things have to be in place for a hurricane (or typhoon as they are called in the western Pacific) to form. Conditions are often enough in place that since 1980 the North Atlantic has had over 400 of them. But during the same period, the United States has had about 3,700 tornadoes. Tornadoes, which are not that common (have you ever actually been in one? Probably not) are an order of magnitude more common than hurricanes. Hurricanes, being much larger than tornadoes, of course, can be much more significant.

Anyway, there have been very few tropical storms in the Atlantic Basin named this year, the few that have achieved a notable status have been quirky, short lived, and stayed at sea. It is almost like all the Hurricane Gremlins went out to the Pacific to work on Haiyan/Yolanda, which was a masterpiece of a storm, being one of the strongest ever and causing immense damage and tragically huge loss of life.

One of the most likely reasons for the poor performance of the Atlantic season this year is said to be the huge injection of Saharan dust into the atmosphere over the equatorial Atlantic ocean early in the season. It might also be vertical wind sheer, which is said to be more common in this basin due to global warming. No matter what, it may take a few more years before we can start to see the magnitude of overall increase in either frequency of tropical storms or intensity of tropical storms that is almost certainly one of the outcomes of climate change.

And now, after many days of virtual inactivity, the North Atlantic has produced an area of disturbance that has a small chance of growing into a tropical storm. It is a non-tropical low pressure system, sitting almost motionless in the middle of the Atlantic Ocean. Conditions to convert this system into a tropical proto-storm may develop and over the next two or three days there is somewhat less than a 1 in 3 chance that it will become a cyclone. It will be very interesting to see if it becomes tropical before it becomes a cyclone, or not. (Tropical and non-tropical cyclones are different.)

The NWS is tracking it, and here is the latest update.

We have a hurricane. Almost. Maybe. Probably. never mind

October 3, 2013Uncategorizedhurricane, Hurricane, Karen, severe weather, Severe weatherGreg Laden

The anemic (perhaps due to climate change, perhaps not) Atlantic Hurricane Season has finally produced a storm that might turn into a hurricane and will hit the Gulf Coast.

Tropical Storm Karen is just north of the Yucatan and is strengthening and heading due north towards Louisana, Mississippi, Alabama or the Florida Panhandle with the current (and very much subject to revision!) bulls eye somewhere around or just east of Mobile.

The current projections indicate that the storm will turn into a hurricane while over the gulf, then weaken to a tropical storm before striking land. But it will still be a near-hurricane force tropical storm at that point and will bring a lot of rain and such with it. Also, it might be big, as in wide.

Atlantic Tropical Weather Update (Updated)

August 25, 2013UncategorizedClimate Change, Climate Change, heat wave, hurricane, Hurricane, Severe weather, Tropical WeatherGreg Laden

So, how has the Atlantic hurricane season shaping up so far?

According to data accumulated by the National Weather Service, as shown (with added items) here …

… we should have had about four or five named storms at this point in the season. Since numbers for this time of year are small, variation is large, so this is not too meaningful but it can give us an idea.

So far, we have had these storms in the Atlantic:

Tropical Storm ANDREA
Tropical Storm BARRY
Tropical Storm CHANTAL
Tropical Storm DORIAN
Tropical Storm ERIN

The next storm will be named Fernand, and it may be forming as we speak:

There is a 60% chance that this stormy blob will turn into a named tropical storm over the next few days. Also there are several interesting looking proto-stormy-blobs between the west coast of Africa and the Caribbean that have promise.

This possible named tropical storm, which would be Fernand, is aimed at Mexico.

UPDATE: The stormy blob is now officially a tropical depression, and there is a hurricane hunter heading for it right now. Expect this to become a named storm later today. Then, it will cross the coast in Mexico and turn back into a stormy blog. But for just a short while, very likely (but maybe not), Fernad will exist.

UPDATE: Yup, Fernand formed, is now over land in Mexico, and will dissipate.

So, we have had five named storms. By the end of the month, we’ll probably have six. And that is about right.

From Intellicast, we have a picture of the immediate and near future jet stream:

The arrows-bearing white lines curving up over the rockies, across the upper midwest, and down along the east coast indicate a highly convoluted wave in the jet stream. This convoluted pattern is most likely the result of the Arctic being warmed (via global warming). This reduces the gradient of heat from the equator to the pole. A steeper gradient would result in a straighter jet stream. When you get a bunch of convolutions (waves) in the jet stream, owing to complicated meteorological math stuff, the waves tend to stall in place. Areas “under the curve” (like, right now, the middle of the US) get big high pressure systems that move warm air to the north, for several days at a time. A result of this would be a big giant heat bubble as shown in the following GIF I copied from Paul Douglas’s blog:

Which, in turn, is likely to seriously exacerbate drought conditions in the region, as shown on this map from US Drought Monitor:

So, really, “Tropical Weather” isn’t just Atlantic Hurricanes, but heat waves at places such as the Minnesota State Fair: