Tag Archives: hurricanes

Hurricanes may start stalling more, and that is bad.

The tempo of storms has changed with global warming. A single storm that might drop X amount of water across a zone one thousand miles in length and hundreds of miles wide may now drop that same amount of water over a zone that is only a few hundred miles in length. Major floods in Calgary, Boulder, Southeastern Minnesota, Duluth, and other very wet rainfall events are now on record as examples of this, and the cause is quasi-resonant Rosbey waves. Continue reading Hurricanes may start stalling more, and that is bad.

Atlantic Hurricane Season 2017 (frequently updated)

UPDATE (Aug 30th)

Irma is a new named storm in the Eastern Atlantic. See this post for details, eventually.

UPDATE (Aug 29th)

There is a system currently raining on Cabo Verde, off the West Coast of Africa (nee Cape Verde) that is expected to develop. It is on the verge of becoming a tropical depression. The National Hurricane Center has estimated that there is a high probability of this stormy feature becoming a tropical storm in a couple of days or so. If it gets a name, it will be Irma, unless some other large rotating wet object takes that name first.

UPDATE (Aug 29th)

How is the Atlantic Season doing so far, in relation to most hurricane seasons?

Using data from NOAA, we can say that on average (using the 1966-2009 baseline) we reach the eight named storm in the Atlantic (Harvey is the eighth) on September 24th. So, we’re having more named storms than average.

This year so far we’ve had 3 hurricanes. Normally one reaches that number of hurricanes on September 9th. That’s a week and a half from now, so we can declare this year a bit above average in this measure, but not spectacularly so.

So far this year we’ve had one major hurricane (Category 3 or above). There are some years with zero major hurricanes, but on average one major hurricane occurs by September 4th. So, we’re close to average now.

UPDATE (Aug 29th)

The following posts discuss various aspects of Harvey

Harvey The Hurricane: Truly Climate Change Enhanced

Is Harvey a failure of the assumption that we’ll adapt to climate change?

Harvey’s effects on petroleum pricing and related things


I’m writing up Harvey here on its own post. This is going to prove to be an important hurricane. If you are in Texas get caught up right now.


Well, finally, something interesting happened in the Atlantic! Tropical Depression Harvey is heading for Texas and in a very short amount of time is going to whip up into a hurricane and hit the Lone Star State right on the coastline.

From the NWS HPC:

1. Harvey is likely to bring multiple hazards, including heavy
rainfall, storm surge, and possible hurricane conditions to portions
of the Texas coast beginning on Friday.

2. Heavy rainfall is likely to spread across portions of eastern
Texas, Louisiana, and the lower Mississippi Valley from Friday
through early next week and could cause life-threatening flooding.
Please refer to products from your local National Weather Service
office and the NOAA Weather Prediction Center for more information
on the flooding hazard.

3. A Storm Surge Watch is in effect from Port Mansfield to High
Island, Texas, indicating the possibility of life-threatening
inundation from rising water moving inland from the coast during the
next 48 hours. For a depiction of areas at risk, see the Storm
Surge Watch/Warning Graphic at hurricanes.gov.

4. The Potential Storm Surge Flooding Map is available on the NHC
website. This product depicts a reasonable worst-case scenario –
the amount of inundation that has a 10 percent chance of being
exceeded at each individual location. Because the Flooding Map is
based on inputs that extend out only to about 72 hours, it best
represents the flooding potential in those locations within the
watch area.

We still hear the yammering that climate change has not affected storms. “They said there would be more storms. There’s no more storms,” they say.

They are wrong in so many ways. For example, the total energy observed in tropical storms around the globe is up. There have been several big huge scary storms in the tropics in recent years, some of which are unprecedented in their size, strength, rapidity of forming, when they formed, where they went, and what they messed up. Other types of storms show either likely increases or, if not clearly increased yet, still show strong liklihood of increasing in the future based on models. Models that are good.

This is from Emannuel 2005, showing his “Power Dissipation Index” over time and sea surface temperatures.

Smoothed Power Dissipation Index (dotted line, a measure of hurricane intensity) versus Tropical Atlantic Sea Surface Temperature (solid black line)

This shows the long term up and down swings in total tropical storm activity, and an overall upward trend exactly as expected with effects from global warming.

This is from “Increasing destructiveness of tropical cyclones over the past 30 years” by Kerry Emanuel, Nature 436:686-688.

See also this post for more details.

Roger Pielke Jr. is one of those yammering fools (I used to try to be nice to him until he accused me of horrible things a few months back and almost none of them were true!) who will tell you this. Roger says, there have bee no more landfalling Atlantic Hurricanes in the US recently than ever before. But trying to figure out what is occurring on the Earth by only considering what the smallest of the Hurricane basins produces, and only counting the small subset of those hurricanes that hit the US (and, by thew way, ignoring some of them such as Hurricane Sandy in order to fudge the numbers) is like trying to get a handle on the frequency of major train derailments by watching the 100 mile length of track you drive along five times a year on the way up north fishing. Nobody would do that. Except Roger.

The normal number of named Atlantic storms is 12.1 of which 6.4 are hurricanes, and 2.7 major hurricanes, in a given year. The record high is 28 named storms, and the record low, is 4.

There have been various predictions for how much storm activity we expect this year. The predictions that are most recent and most reliable call for 11, 12, 11-15, 14, 11-17, and 15.3 storms. So, generally, close to average plus.

The prediction I watch most closely is from PSU’s Earth System Science Center. PSU has been making very accurate predictions for a number of years. For this year, they predict 15.3 +/- 3.9 named storms this year (i.e., about 11 to 20 with the best guess being 15). Their prediction will drop a little if there is a mild El Niño this year, but that seems increasingly unlikely. Also, PSU has a second alternative model that produces a lower estimate, of around 12.4.

So, in short, barring an El Niño, we can expect a near average but slightly above average year for Atlantic hurricanes. And no, that does not mean that global warming is not happening. It means that no derailments are expected along a particular section of recently maintained rail track.

Anyway, for the second year in a row, IIRC, we got cheated on our A storm. Below, I’ve put the official list of storm names for the Atlantic 2017 season (as headings, we’ll fill in info as the year progresses), but the first tropical storm to talk about today, 19 days into the season, is Bret (one ‘t’). Arlene happened last April.

Tropical storms don’t happen in the Atlantic in April. ‘Cept for Arlene. Generally, it seems like the boundaries are becoming enfuzzied. Expect more “extraseasonal” storms over the next few years, and expect eventually, perhaps a decade from now, for the National Hurricane Center crew to be asked to start watching year round, because a tropical storm that hits your fleet in April is still a tropical storm. Even if Roger says it doesn’t exit.


Bret formed near the very southern edge of the Atlantic Hurricane basin.

This is the earliest far south forming hurricane in the Atlantic Basin. So, our first storm of the season happened months early, the second storm hundreds of miles south, compared to normal. Roger that.

Bret will menace the northern edge of South America, then in a few days from now it will be gone. Bret is not expected to strengthen and will not be a hurricane. Nor will it hit the United States of America. Therefore, according to Roger, Bret, as novel as it is, does not exist.


The next storm, to be named Cindy, is very likely to form from a disturbance now seen in the south-central Gulf of Mexico. This is fairly typical place to see a tropical storm or hurricane form this time of year. Cindy will likely become a north-moving tropical storm, and will likely stay just at tropical storm strength, coming ashore somewhere between Houston, Texas and Morgan City, Louisiana. The chances of Cindy wetting down NOLA is very good, but again, this will not be a hurricane. This will happen some time late Wednesday, most likely.

While possible-Cindy would transform from a tropical storm to a depression with landfall, the storm will track up the Mississippi and cause lots of rain.



















Atlantic Storm Update: Prospects of Gaston, Hermine, Ian and Julia

Original Post:

The Atlantic storms are getting interesting.

Two different systems are poised to become named storms, but it is not clear which one will be awarded the name Hermine, and which one Ian. If the storm recently near Cuba develops as expected, it could become a weak hurricane before making landfall along Florida’s Gulf coast. This will not likely be a very impressive hurricane, but it will be big and wet, and the area is already experiencing too much water. Flooding will ensue.

A third system is moving off of Africa, with 40% chance of forming into a storm over the next several days. This system looks really promising for a hurricane.

Hurricane Gaston is still hanging out in the middle of nowhere, but it will likely menace the Azores.

Update (Wednesday AM):

Gaston is at present a Major Hurricane, and will continue heading east, weakening to a tropical storm before arriving in the Azores.

There are three other systems of interest. The Cuban storminess that has been on everyone’s mind for a while refuses to get organized into a namable storm. Another, in the Atlantic, is also developing slowly. Both disturbances are likely to become sufficiently organized and strong to become named tropical storms, and that is likely to happen before sunset today. Which one will get organized first to claim the name of Hermine? Which one will become Ian? Neither is likely to spin up to hurricane strength.

The more southerly of the two storms, in the area of Cuba, is likely to sweep across the base of the Florida Peninsula and cause a mess (but as a tropical storm, not a hurricane). the other is likely to stay out to sea, in the Atlantic.

Meanwhile, the disturbance off the African Coast (to the right of the map) retains a certain amount of ambiguity as dry air reduces its chances of formation. But, it will reveal its will over the next several days as it moves west. We will see.

It is possible that we could see four names storms churning away simultaneously in the Atlantic. That is probably not a record, but it could be. My impression is that this happens now and then. Do you know? There have been as many as 8 storms formed in a given month (but not necessarily extant at the same time) a few times. So, four at the same time may be highly unusual.


OK, I found this about simultaneous storms:

Four hurricanes have existed simultaneously twice: August 22, 1893 and September 25-27, 1998 with Georges, Ivan, Jeanne and Karl as hurricanes. In 1971 there were 5 tropical cyclones simultaneously, but only 2 were hurricanes. [source]

Note, that refers to hurricanes, not named storms. So it is not an answer to the question.

Update (Wed PM):

Hermine exists and is expected to strengthen over the next two days or so, but not to full hurricane strength, before hitting florida near the base of the peninsula. After that, it will come out the other side, and hug the coast until at least North Carolina. Then it will go off to sea.

The second disturbance in the Atlantic will turn into a named storm, perhaps within a day or two, and Gaston will still be a named storm, so there will be three named storms at the same time. Gaston will be on or near the Azores by the end of the day Friday. The fourth stormy event, off the coast of Africa, is looking less likely to turn into a named storm any time soon.

The 2016 Atlantic Hurricane Season So Far. Keep an eye on Hermine.

A quick note about the current Atlantic hurricane season. With resect to just the US, we’ve had a fairly low level season, and it is easy to become complacent about this time, but in fact, the risks from Atlantic hurricanes rise about this time of year, so pay attention. Watch for Hermine. More on that below.

We are approximately in the middle of the 2016 Atlantic Hurricane Season, by calendar time. The number of named storms (tropical storms plus hurricanes) predicted for this year is about 14, taking the average of all the predictions made so far, and there have been 7 storms including one currently brewing in the middle of the Atlantic. So, perhaps we are right on track.

But, the first of those seven storms actually happened last year, but after the Hurricane Prediction Center had closed the book on the 2015 season, so Hurricane Alex got dumped into the 2016 season. (It happened in Janurary.) So, we are a bit behind in the total number of named storms.

But, we are not really half way through the hurricane season. It starts on June 1 and ends on November 30th, though as was the case with Alex, individual storms sometimes fail to get the memo. But, more importantly, the peak of the season tends to be around September 10th, and the distribution of Atlantic hurricanes over they year tends to be a bit skewed, with the latter half of the season being more active.

During the period 1851 to 2015 there were 1619 Atlantic tropical storms or hurricanes recorded. 609 of them happened prior to the end of August. The remaining 1010 happened in September, or later, with September and October having most of them.

So, roughly speaking, if we are half way to the predicted 14 named storms now and still in late august, one could guess that we’ll slightly exceed average expectations, but likely fall within the range of those expectations. We’d have to have over 20 or so named storms to raise the eyebrows of most of the predictors.

I get the impression that the percentage of named Atlantic storms that made landfall this year has been on the high side, though there has been no catastrophic landfall to date.

Katrina made landfall in about four days from now (in 2005). Among the deadliest, Sandy (which was a Hurricane that ate another storm and became too big and powerful to maintain its status as a hurricane by landfall, thus dubbed a “super storm” and enigmatically left off most hurricane lists) was later in the year, as were Stan, Jeanne, Mitch, Gordon, Fifi-Oriene, Flora, Jeremie, several other storms. Of recent deadly storms, Katrina was relatively early, and only 1979’s David came close (formed August 25th, fizzled out on September 8th).

So, speaking just of the more powerful storms, that is generally a phenomenon of September or October and now and then November.

Gaston is the currently active named storm. It is likely to form into a hurricane over the weekend, veer right before coming too close to Bermuda, and remain pretty far out in the Atlantic. There are no clear predictions of what it will do by mid week, but it is likely to weaken a bit on Wednesday. Gaston will be in hurricane-hostile territory at that time, so may be it will just go away.

Hermine is the name that would be given to what is now a tropical disturbance, should it form a tropical storm. The changes that it will do so are not small. If Hermine forms up into a reasonable storm, the chances that it would miss already-water-logged Florida are very small. I expect Hermine to be a significant weather event for the southern US.

Stormy Weather and Climate Change This Week

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:

Super Typhoon Chan-hom

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.

AGW Class Cyclone Pam Nearing Vanuatu

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.

Odile, Polo, and the Eastern Pacific Hurricane Season 2014

Odile was the strongest hurricane to strike the Baja Peninsula during the period of available data, roughly similar to Hurrican Olivia (1967). The storm reached Category 4 strength but was then weakened because of interaction with the effects of a prior hurricane in the area (Norbert). At the moment, Odile is a tropical storm and still in the Baja. There was flooding, and two fatalities, including a lightning strike and a nine year old boy taken by floodwaters. Several building in Acapulco were damaged. There has been a lot of damage and disruption in the Baja region.

Tropical Storm Polo is currently south of Mexico and is expected to stay away from the coast, and it is not clear that it will reach Hurricane strength. If so, only for a brief time.

Hurricane Iselle was the strongest tropical cyclone to hit Hawaii (the big island).

Hurricane Marie was the first Category 5 Pacific hurricane in the region in four years.

Hurricane Genevieve was the first hurricane to pass through all three defined Pacific hurricane basins since 2003.

Including Polo, there have been 17 named storms in the Eastern Pacific so far this year. Eleven have been hurricanes. The average Eastern Pacific hurricane season has 15.4 (range 7-25) storms with 8.4 hurricanes (range 3-16). Officially the season ends on November 30th. So, this is clearly an exceptional year.

Typhoon Rammasun

There is a major typhoon (hurricane) in the Western Pacific, Rammusan, which has already caused flooding and damage in the Phillipenes, where it killed 12 people, heading for southern China, and expected to affect northern Vietnam later on. From Accuweather:

Warm ocean waters combined with light wind shear will allow the storm to remain well organized through Friday as it approaches Hainan Island. Rammasun will likely bring widespread winds of 100 mph to northern Hainan Island on Friday afternoon and Friday night with higher gusts. Widespread wind damage is expected across northern Hainan, as well as the Leizhou Peninsula to the north.

Jeff Masters has a detailed analysis here.

UPDATE Friday AM: The typhoon is battering the coast in Hainan and Guangdong provinces in southern China China, and the Chinese have classified this as a “red alert” typhoon, the highest category for them.

Why Was Typhoon Haiyan/Yolanda So Powerful, and is this a trend?

I’m sure the measurements are still being checked and adjusted but it is clear that Typhoon Haiyan/Yolanda was one of the most powerful tropical cyclones (termed “Typhoon” in the western Pacific) ever recorded. There are several ways to measure how big and bad a tropical cyclone is including it’s overall size from end to end, how low the barometric pressure gets, how high the sustained wind speed is, and how wide that wind field is. In addition, when a typhoon hits land details matter. The front right quadrant of a counter-clockwise spinning typhoon packs the maximum punch and if that part of the storm enters an embayment during high tide the storm surge can be immense. It seems that the storm surge for Haiyan/Yolanda was in the many tens of feet range, and quite possibly will be found responsible for the largest part of the still uncalculated death toll.

But here I want to look at one single factor that almost certainly contributed to the growth of Haiyan/Yolanda into a very powerful storm, a factor that probably doesn’t usually play into a storm’s strength. I refer to an anomaly in sea surface temperatures that was almost certainly caused by global warming, as part of a general warming of the ocean. But first a bit of background on the link between sea surface temperature and hurricanes. This is one of several factors that may be involved in climate change related effects on tropical storm intensity, a situation with which we should be concerned.

Tropical cyclones run on heat, and much of that heat comes from the sea surface. If the surface of the ocean is below a certain temperature, about 82 degrees F, about 28 degrees C, a hurricane or typhoon is very unlikely to form. Above that temperature, if other conditions are right, it may form. Warmer seas can make bigger or stronger storms, and as the storm passes over the ocean, the temperature of the sea surface has a strong influence on whether the storm increases or decreases in strength . As the storm moves over the sea, the interface between the windy storm and the roiling ocean becomes something of a mess, as though the surface of the ocean was in a blender, and there is a lot of exchange of heat across that interface. Also, deeper, cooler water is mixed with warmer surface water. A powerful storm moving across the ocean will leave in its wake a strip of cooler water. This sometimes causes subsequent storms moving along the same path to be weaker or to downgrade in strength more quickly.

This should indicate, one would think, that as sea surface temperatures (SST) have gone up with global warming, there should be more “hurricane” out there on the oceans. It has been hard to make the link between global warming and frequency of hurricanes, however. This may be because of the nature of hurricane formation. Once a hurricane forms in a given spot and gets big, it may reduce the chance of the next hurricane forming. Also, hurricanes are usually born as waves in a very large scale pattern of air masses. The total number of waves that form may not change with global warming, and the hurricane season is only a part of the year, and other factors have to come into play that are also ponderous in their timing to turn a wave into a major storm. An analogy might be this: Imagine that everyone in the working population of a downtown neighborhood becomes hungrier, perhaps because all the companies they work for insist on a two hour high intensity exercise program for everyone to lower their health insurance costs. Will this increase in hunger mean more lunches, snacks, and dinners consumed in the local restaurants? Or will the lunches, snacks, and dinners become larger, with people ordering more food with each sitting? Since there are only so many opportunities to go grab a bite to eat, there will probably be very few additional visits to the local eateries, but more food may well be consumed per event. Increased SST may be like increased hunger. There may not be very many more hurricanes, but among those that occur, some may be much stronger.

There is evidence for this. Kerry Emanuel did a study several years ago that linked sea surface temperatures in the Pacific with an index called PDI, which measures the overall energy involved in typhoon/hurricane activity. (Emanuel, K. (2005). Increasing destructiveness of tropical cyclones over the past 30 years, 436(August), 686–688. doi:10.1038/nature03906.) He came up with this graph:


The graph shows that hurricanosity, as it were, goes up and down with sea surface temperature more or less. And, SST goes up and down with decadal oscillations like ENSO (El Nino) but with an overall upward trend caused by global warming.

Here’s the new part. If you look at a map of Sea Surface Temperature you are seeing a measurement of, well, the surface of the sea … the top of the water. As a hurricane chugs along on the surface of the sea, turning the top meter or so of ocean into spray and creating a very wavy situation, that heat is certainly directly affecting the storm, but the temperature of the water several meters down also matters. It turns out that sometimes this shallow-deep water (as opposed to deep deep water, way down farther) can be quite warm. When that happens, the dissipation of SST does not occur to the same degree. The leading edge of the hurricane gets a good dose of heat from the surface, but instead of the SST dropping as the top warm water is mixed with somewhat deeper cooler water, the heat supply is not attenuated, or at least not by much, as the massive storm moves along. More of the storm gets more heat, and the storm as a whole gets more heat. And there’s more heat left over for the next storm.

We think this happened with Haiyan. Have a look at the following map. It is sea surface temperature anomaly (how much more or less than expected the SST is) for the top 50 meters for the western Pacific at the time of the typhoon. The Philippines is down near the bottom of the map straddling the 10 and 15 degree N lines. (Maps are from here) Notice that the surface is not unusually warm.


This does not mean that the sea surface was not warm. It was plenty warm as it is this time of year i that part of the ocean, just not warmer than expected. Here is the raw temperature (not anomaly) map so you can see that the tropical ocean is, well, tropically warm:


The purple area along the south is sufficiently warm to form typhoons. The ocean to the east of the Philippines is warm enough to form typhoons, but is there any source of extra heat to form a super typhoon? Have a look at this map. This is the water temperature at depth, here at 100 meters. This is an anomaly map, so its shows if the temperature is more (or less) than expected. Notice that east-west band of red indicating several degrees warmer than it usually is, at depth.


[Updated:] Here’s the same map with Haiyan/Yolanda’s track and history, graphic generated by Jeff Masters.


So, it would appear that Haiyan/Yolanda passed over the usual very warm waters that allow the formation of typhoons, but also, over water that was warm at depth so as the top of the sea is churned up by the growing storm, there would be extra heat to feed that storm.

One final map. This is the actual temperature (not anomaly) at the 100 meter level. Notice the purple area.


At 100 meters depth, the sea was warm enough to form a typhoon. That, dear reader, is extreme.

The same thing happened with Katrina. According to a report from NOAA:

A number of factors contributed to making Katrina a strong Category 5 hurricane…Sea surface temperatures (SST) in the Gulf of Mexico were one to two degrees Celsius above normal …, and the warm temperatures extended to a considerable depth through the upper ocean layer. Also, Katrina
crossed the “loop current” (belt of even warmer water), during which time explosive
intensification occurred. The temperature of the ocean surface is a critical element in the
formation and strength of hurricanes.

We know that the ocean is absorbing a lot of the extra heat caused by global warming. Well, this is some of that heat, causing megastorms.

I’ve noticed that climate science denialists are very adamant about two things: Denying the importance of major storms like Haiyan, and denying the fact that heat is going into the oceans. Perhaps they see the link, and are frightened that people will believe that anthropogenic changes to our climate can kill thousands of people at a time, in a few hours, through the mechanism of anomalously high temperature at modest depth below the surface of the already tepid tropical sea.

It is time for action.

Climate Change, Cat 6 Hurricanes, Al Gore

These things are all connected.

A couple of days ago a good ally in the climate change fight … the fight to make people realize that climate change is not some librul conspiracy to raise taxes on the rich … goofed. It was a minor goof, barely a goof at all. We do not yet know the nature of the goof but it was somewhere between saying something in a slightly clumsy manner and a bit of misremembering something that happened in 2005 during an interview. That’s it. Nothing else to see here.

But that goof has been wrenched form its context and turned into a senseless and embarrassingly stupid attack on science by the likes of Anthony Watts, who really is one of the more despicable people I know of on the internet outside the MRA community (even he’s not that bad, and I’ve even noticed a sense of humor now and then).

It all started when Ezra Klein published an interview with Al Gore on Wonkblog. It was good interview and it was nicely written up. They talked about crossing the 400 ppm mark, electricity prices from alternative energy sources, the nature of technological change vis-a-vis green energy, international climate treaty making and cap and trade strategies, the politics of climate denial and the shift from being concerned about climate to denying the science in the Republican party, what’s going on in the current administration, geoengineering, storms, and all sorts of other things.

But then Jason Samenow, of the Captial Weather Gang, noticed something in the interview that seemed wrong. He wrote a blog post about “Al Gore’s Science Fiction” to make sure that every body knew about this apparent error. Then, the Union of Concerned Scientists, in an apparent paroxysm of well meant, but really, totally bone-headed, intent to demonstrate that people who are on board with climate science can criticize each other so we must all be for real, restated that something Vice President Gore had said to make him look like he was some sort of dummy, which he is not. The Union of Concerned Scientists, realizing their error, issued a pretty standard notpology. The notpology was disappointing. I know that people there understand that they got it all wrong … apparently at the institutional level they can’t just say “oops, sorry” but rather something more like “oh yes, things were misunderstood, but still, our point is valid.” We are reminded once again that institutions do have their limits.

Anyway, Ezra, for his part, dug back into memory and consulted with Vice President Gore and his staff and clarified what he said Al Gore said. But, that was not before lame, mean spirited, ill intentioned, ignorant, and embarrassingly giddy offal started to spew from the denialists. Anthony Watts got into it because that is how Anthony Watts masterbates. He draws cartoon glasses and piles of dog poo on pictures of Al Gore and that gets him off. The Hill jumped in with a piece by Ben Geman about how Al Gore goofed. The Free Republic came in its pants too. Almost nobody made mention of a single other thing in the interview, nobody checked their facts, nobody understood the original meaning of Vice President Gore’s remarks which were, in fact, dead on. But everybody got dirty. Shame on all of them (to varying degrees).

Here’s what actually happened (never mind the interview, the Union of Concerned Scientists concern trolling, or the circle jerk of denialism with Anthony Watts in the middle).

First, storms got worse. Yes, yes, you will hear climate science denialists insisting that they have not gotten worse, but they have. Hurricanes are worse now than they were decades ago, and global warming is implicated in that.

Then, some people, including some scientists and science communicators, discussed the idea of adding a Category 6 to the Saffir-Simpson scale. This conversation happened in and after 2005. The Cat Six storms would be those greater than 151 or 160 knots. Not many storms have ever been this strong, but there are a few. Robert Simpson, of the Saffir-Simpson Scale, suggested that this would not be necessary because the whole idea of the scale was to represent storms in terms of human and property impacts, and a Cat Six storm would not really be worse than a Cat Five storm because a Cat Five storm is bad enough . He said “…when you get up into winds in excess of 155 mph (249 km/h) you have enough damage if that extreme wind sustains itself for as much as six seconds on a building it’s going to cause rupturing damages that are serious no matter how well it’s engineered.” (I disagree strongly with that statement, by the way.)

There are indeed reasons to revisit the Saffir-Simpson scale. There is a lot of information lost by just looking at wind speeds. Paul Douglas turned me on to this graphic demonstrating that when it comes to hurricanes, size matters:


Look closely. There are TWO Pacific Cyclones (aka Hurricanes) represented in that picture. Reminds me of the drawings designed to demonstrate the vast range of body size in primates, like this one:


But I digress. The point is, Saffir-Simpson is inadequate for what we need. We should be able to take a metric used for hurricanes and add the metric up at the end of the season and say something pretty accurate about how much energy was packaged in those beasts that year and in that ocean basin. Indeed, people who study hurricanes do this … they measure hurricanes in various ways. But the Saffir-Simpson scale is the most well known, and it only measures maximum sustained winds and nothing else, and the scale is not open ended so the biggest storms look like the second biggest storms.

So, given that storms are getting worse and the scale is inadequate, the discussion of at least adding a Cat Six happened, and this is what Gore mentioned.

But the Union of Concerned Scientists, or should I call them for now the Onion of Concerned Scientists, said this of Gore’s statement (and I quote mine):

Al Gore, Climate Science, and the Responsibility for Careful Communication…

When I was in fourth grade, I wrote Vice President Al Gore a letter … I believed then, as I do now, that he is a strong voice for issues with an environmental component such as climate change. And, importantly, he has become, to many people, the public face of climate science….But unfortunately he recently got it wrong about the science of climate change…Gore inaccurately suggested that the hurricane scale will now include a category 6… this is untrue. There are no plans by the National Hurricane Center—the federal office responsible for categorizing storms—to create a new category….Since writing that letter as a ten-year-old, I’ve earned a degree in atmospheric science and learned to value to the role that science plays in informing public policy. Science—and climate change especially—needs effective communicators…

and so on and so forth. How annoying of Al Gore to be so annoying. What a disappointment. I WAS A CHILD AND I WROTE HIM A LETTER AND NOW HE DOES THIS TO ME!!!

OK, take it down a notch.

Al Gore was referring to the discussion I mention above. Perhaps he made this reference clumsily. Ezra may have quoted him wrong, and he now states that is likely (he’s not been able to check his tape yet) so them message got further garbled. Then, some bloggers including one at Union of concerned Scientists decided to make a case of it. And now we have a nice science denialist orgy going with Head Orgy Master Debater Anthony Watts running the show. Joe Romm has more on the interview and what Vice President Gore said here.

There are three things you need to take away from this:

1) Al Gore is an effective communicator and knows a lot about climate science. If you hear that he said something that is wrong, before you get all “concerned” consider the possibility that he didn’t.

2) We really do need to look at how we characterize hurricanes.

3) The science denialists really have nothing, if this is what gets them so excited. They should get out more.

Levees and the National Flood Insurance Program (NAP)

The National Academies Press of the United States has recently released a report that will be of interest to those of you concerned with climate change (which better be every one of you dammit!). The report talks about increasing floods due to weather whiplash and sea level rise due to glacial melting (and subsidence), mainly in relation to the levees program and insurance, but also more generally. Here’s a small excerpt to give you a flavor:

Community flood risk scenarios will continue to evolve as change occurs. Climate change will have a variety of regional impacts, and the geographic location of a community will affect how changing conditions affect risk. Some areas will have more droughts, some will have more frequent floods, and others will have more intense floods. Research to understand these hydrologic changes is ongoing (NRC, 2011, 2012a). A recent special report of the Intergovernmental Panel on Climate Change (IPCC, 2012) indicates a likely increase in many regions of the frequency of heavy precipitation events, and when coupled with increasing vulnerability presents a myriad of challenges for coping with climate-related disastersIPCC. Galloway (2009) cites 11 major international studies conducted from 1987 to 2002 that all predict significant climate change–induced hazards, including increased flooding, higher mean atmospheric temperatures, higher global mean sea levels, increased precipitation, increased strength of storms, more energetic waves, storm surges that reach further inland, undercapacity of urban sewer- age and drainage systems, increased vulnerability of port cities, and disproportionate impacts on disadvantaged population segments (Galloway, 2009). The rise in sea level and the increase in storm surge due to climate change puts many coastal areas at risk from intensified flooding (NRC, 2010).

Hirsch and Ryberg (2012), in examining trends in annual floods at 200 stream-gauge sites in the United States, found that , while there appeared to be no strong statistical evidence for flood magnitudes increasing with increasing global mean carbon dioxide concentration, there were differences in flood magnitudes among the four quadrants of the conterminous United States (Figure 6-8). They indicate that the attention should be paid to the effects of changes in the relative “importance of the role of snowpack and rain on snow events.” Raff (2013) suggests that the increase in magnitude of floods in the northeastern and midwestern United States (Figure 6-9, Upper Right), may have consequences in the Upper Mississippi, Ohio, and Missouri watersheds (Hirsch and Ryberg, 2012; Raff, 2013).

The Draft National Climate Assessment, issued in January 2013 by the National Climate Assessment Develop- ment Advisory Committee, begins with the statement:

Climate change is already affecting the American people. Certain types of weather events have become more frequent and/or intense, including heat waves, heavy downpours, and, in some regions, floods and droughts. . . . The largest increases have occurred in the Northeast, Midwest, and Great Plains, where heavy downpours have exceeded the capacity of infrastructure such as storm drains, and have led to flooding events and accelerated erosion.

The report goes on to point out the increasing vulnerability to flooding of those in floodplains and coastal areas

You can buy the report for a mere $53, or download it for free. (Downloading from the NAP involves signing in and stuff, but it is pretty easy, though at the moment their server is running a bit slow since they just publicized the report and everybody wants a copy of it.)

Go HERE to get the report.

Will there be a lot of hurricanes in 2013?


The Tropical Meteorology Project at Colorado State University makes annual predictions of hurricane season activity, and they released one of these predictions today. This particular group has a good track record, although I would worry that they tenaciously hold to the idea that global warming is not a factor in hurricane development despite the fact that some of the factors (a disrupted ENSO and high SST) that are most affected in the Atlantic by global warming actually drive their predictions. Still, their predictions seem to be based on good empirical data and are probably robust. (Other season forecast information is to be found below).

El Nino conditions tend to reduce hurricane activity, and the warmer the waters in the North Atlantic, the more likely hurricanes are to form from tropical depressions, the stronger they are likely to be, and the longer they are likely to last.

This year, El Nino conditions are unlikely to develop, and sea surface temperatures in the North Atlantic are unusually high as they have been for a few years.

The TMP has released this PDF of their report, which states:

We anticipate that the 2013 Atlantic basin hurricane season will have enhanced activity
compared with the 1981-2010 climatology. The tropical Atlantic has anomalously
warmed over the past several months, and it appears that the chances of an El Niño event
this summer and fall are unlikely. We anticipate an above-average probability for major
hurricanes making landfall along the United States coastline and in the Caribbean.
Coastal residents are reminded that it only takes one hurricane making landfall to make it
an active season for them, and they need to prepare the same for every season, regardless
of how much or how little activity is predicted.

TMP predicts that there is a 72% chance of at least one category 3 or above hurricane landing somewhere on the US coastline (the average probability over the last century is 52%). There is a 48% of such a landfall along the Atlantic coast plus Florida not counting the panhandle (compared to the century average of 31%) and a 47% probability for the Gulf Coast on the Florida Panhandle and points west to Brownsville (compared to 30%). The chance of at least one category 3 or stronger hurricane hitting points in the Caribbean is 61% (compared to 42%).

The forecast predicts that there will be 18 named storms active over 95 days, of which 9 will be hurricanes, active over 40 days, of which 4 will be Category 3 or above.

The Weather Channel is saying the following about the 2013 season:

The Weather Channel released its first 2013 Atlantic hurricane season outlook on April 8, 2012, calling for another active season.

The forecast calls for a total of 16 named storms, 9 of which are expected to become hurricanes, including 5 major hurricanes (Category 3 or higher on the Saffir-Simpson Hurricane Wind Scale).

These forecast numbers are above the long-term average from 1950-2012 (12 named storms, 7 hurricanes, 3 major hurricanes) and slightly above the averages for the current active era from 1995-2012 (15 named storms, 8 hurricanes, 4 major hurricanes).

The Weather Company’s WSI says this:

Weather Services International (WSI) expects another active tropical season this year, with 16 named storms, nine hurricanes, and five intense hurricanes expected (16/9/5). This compares to the 1950-2012 normals of 12/7/3 and the more recent “active period” (1995-2012) normals of 15/8/4.

Researchers at UCL, UK (PDF) predicts 3-4 “intense hurricanes” out of 7-8 hurricanes with 15-16 tropical storms:

The TSR (Tropical Storm Risk) April forecast update for Atlantic hurricane activity in 2013 continues to
anticipate an active hurricane season to moderate probability. Based on current and projected climate
signals, Atlantic basin tropical cyclone activity is forecast to be about 30% above the 1950-2012 longterm norm but slightly below the recent 2003-2012 10-year norm. The forecast spans the period from 1st
June to 30th November 2013 and employs data through to the end of March 2013. TSR’s two predictors
are the forecast July-September trade wind speed over the Caribbean and tropical North Atlantic, and the
forecast August-September 2013 sea surface temperatures in the tropical North Atlantic. The former
influences cyclonic vorticity (the spinning up of storms) in the main hurricane track region, while the
latter provides heat and moisture to power incipient storms in the main track region. At present, TSR
anticipates both predictors will have a small enhancing effect on activity.

Weather Underground’s MAweatherboy1 posted this last month:

I foresee a season that will see near to above average activity. One of the main factors we look at to determine this is the ENSO, which involves the temperature of waters in the Pacific Ocean. Warm Pacific waters, called El Nino if the anomaly is greater than 0.5 degrees Celsius, tend to suppress activity in the tropical Atlantic, while cooler than average Pacific waters, called La Nina if the anomaly is greater than 0.5 degrees Celsius, tend to enhance activity. … This year, I am expecting a very neutral ENSO, with average, season-long (June 1-November 30) Pacific water temperatures that are in the key regions likely not averaging more than 0.2 degrees Celsius above or below average, although I would favor the cooler end of that range if anything. The Southern Oscillation Index (SOI) is an important component in determining ENSO. Positive SOI values promote cooler Pacific waters, and vice versa. SOI values have been mostly negative this winter, though not by much, and I do not foresee any huge changes in this. Neutral conditions like this tend to promote near normal, or in some cases above normal activity. The record breaking 2005 hurricane season was primarily influenced by neutral ENSO conditions.

Photo Credit: NASA Goddard Photo and Video via Compfight cc