A record quiet start to the 2010 Northern Hemisphere tropical cyclone season

By: Dr. Jeff Masters , 3:42 PM GMT on August 12, 2010

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The remnants of Tropical Depression Five have re-organized this morning, and the storm is pounding Southeast Louisiana with heavy rains. Radar imagery out of New Orleans shows that the remains of TD 5 have have formed some respectable low-level spiral bands that have brought heavy rains in excess of five inches in some areas. However, with the circulation center now moving over land, not much further development can occur.


Figure 1. Morning radar image of TD Five's remains.

Why so quiet in the Atlantic?
The Tropical Atlantic is quiet, and there are no threat areas to discuss today. The Invest 93 system we were tracking has been destroyed by dry air and wind shear. There are a couple of long-range threats suggested by some of the models--the GFS model predicts a tropical depression could form off the coast of Mississippi six days from now, and the NOGAPS model thinks something could get going in the Gulf of Mexico's Bay of Campeche seven days from now. Neither of these possibilities are worthy of concern at present. Overall, it's been a surprisingly quiet August, considering the pre-season predictions of a hyperactive season. According the National Hurricane Center, this hurricane season has been exactly average so far. There have been three named storms and one hurricane as of August 12. The average date of formation of the third named storm is August 13. One hurricane typically forms by August 10. One reason for this year's inactivity may be an unusual number of upper-level low pressure systems that have paraded across the tropical Atlantic. These lows, also called Tropical Upper Tropospheric Trough (TUTT) lows, tend to bring high wind shear that inhibits tropical cyclone formation. The other major factor appears to be that vertical instability has been unusually low in the Atlantic over the past month. Instability is measured as the difference in temperature between the surface and the top of the troposphere (the highest altitude that thunderstorm tops can penetrate to.) If the surface is very warm and the top of the troposphere is cold, an unstable atmosphere results, which helps to enhance thunderstorm updrafts and promote hurricane development. Since SSTs in the Atlantic are at record highs, enhancing instability, something else must be going on. Dry air can act to reduce instability, and it appears that an unusually dry atmosphere over the Atlantic this month is responsible for the lack of instability.


Figure 2. Vertical instability (in °C) over the Caribbean (left) and tropical Atlantic between the Lesser Antilles Islands and coast of Africa (right) in 2010. Normal instability is the black line, and this year's instability levels are in blue. The atmosphere became much more stable than normal in both regions at the end of July. This lack of instability also extends to the Gulf of Mexico and North Atlantic Ocean between Europe and North America, as well as the Western Pacific east of the Philippines, and the South Indian Ocean. Image credit: NOAA/CIRA.

A record quiet start to the 2010 tropical cyclone season in the Northern Hemisphere
What is really odd about this year, though, is the lack of tropical cyclone activity across the entire Northern Hemisphere. Usually, if one ocean basin is experiencing a quiet season, one of the other ocean basins is going bonkers. That is not the case this year. Over in the Eastern Pacific, there have been five named storms and two hurricanes. The average is seven named storms and four hurricanes for this point in the season. This year's quiet season is not too surprising, since there is a moderate La Niña event underway, and La Niña conditions usually supresses Eastern Pacific hurricane activity. But over in the Western Pacific, which usually generates more tropical cyclones than any ocean basin on Earth, it has been a near-record quiet season. Just four named storms have occurred in the West Pacific this year, and the average for this date is eleven. Only one typhoon season has had fewer named storms this late in the season--1998, with just three. The total number of named storms in the Northern Hemisphere thus far this year is fifteen, which is the fewest since reliable records began in 1948. Second place belongs to 1983 and 1957, with eighteen named storms. According to an email I received from NOAA hurricane researcher Gabe Vecchi, the lack of tropical cyclones so far this year in the Northern Hemisphere is between a 1-in-80 and 1-in-100 year event.

So, what is causing this quiet tropical cyclone season? One possibility is that since Northern Hemisphere land areas have heated up to record temperatures this summer, this has created strong rising motion over the continents. This rising motion must be compensated by strong sinking motion over the adjacent oceans in order to conserve mass. Sinking air causes drying and an increase in stability. Another possibility is that the unusual jet stream configuration that is responsible for the Russia heat wave and record flooding in Pakistan is also bringing dry, stable air to the Northern Hemisphere's tropical cyclone breeding grounds. It is also possible that climate change is causing the reduction in tropical cyclone activity, for a variety of complex reasons. Computer simulations of a future warmer climate generally show a reduction in global number of tropical cyclones (though the strongest storms get stronger), and it is possible we are seeing a preview of that future climate. Or, this year's quietness may simply be natural variability. It will be interesting to see when the Russian heat wave breaks if vertical instability over the Atlantic increases back to normal levels. Current forecasts from the GFS and ECMWF models project the Russian heat wave to break late next week.

Moscow's air remains clear; coolest temperatures in two weeks
Moscow's winds remained favorable for keeping smoke away from the city today, and temperatures "cooled" to at Moscow's Domodedovo airport to 33°C (91°F)--the lowest maximum temperature since a high of 32°C (90°F) was recorded on July 30. Moscow's airport has reached a maximum temperature of 30°C (86°F) or higher for 35 consecutive days now (at Moscow's official observing site, the Moscow Observatory, this string is 30 days.) Moscow's average high temperature for August 12 is 20°C (68°F). Moscow's high temperatures have averaged 15°C (27°F) above average so far this August--a truly extraordinary anomaly for a country so famous for its notorious cold weather. The latest forecast for Moscow calls for high temperatures of 30 - 33°C (86 - 91°F) Thursday through Monday. This is still 23°F above normal, but will be a welcome change from the extreme heat of the past two weeks. Long range forecasts from the ECMWF and GFS models continue to suggest that a series of troughs of low pressure will begin to attack the ridge of high pressure anchored over Russia beginning on Wednesday, bringing cooler temperatures just 5°C (8°F) above average to Russia late next week. By ten days from now, the ECMWF model shows a strong trough of low pressure over Moscow, and a end to the Great Russian Heat Wave of 2010.

Next update
I'll have an update Friday morning.

Jeff Masters

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Quoting IKE:
As Harry Caray would say when an opposing player belted one 450 feet....it might be...it could be....it is....a fishie...



Ike you have lost your mind again!!!

Clearly S Florida
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887. IKE
Quoting DestinJeff:


To be fair, Harry Caray would sometimes say the same thing for a pop-up to 2nd base ... after a few Buds.


He use to crack me up trying to say players names like Bobby Abreu...after two cases of cold Bud Light.


Quoting Cotillion:
Well, the 18z looks better for Bermuda, but it is all a long way out.



GFS might be on to something and it's usual for that model to flip-flop on track that far out. It may show it heading into the GOM on the next run.

Problem is...a select few on here will jump on that GOM run and the...."it's a definite track to Florida" crowd will show up.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Keep those fish storms coming. It won't be long until stronger troughs start to come out of Canada into the eastern U.S. as the fall season approaches.
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Anyway, I'll keep this open 'til tomorrow about this time and post results in the blog then...

Added so far:

12. Chris 2006 "Sheared again… Naturally"
13. Portlight 2008 formation "We are the Blog"
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Quoting Portlight:


The outpouring of generosity from the blog community in support of our relief efforts after hurricane Ike ...


We miss you. Thanks for the continued efforts.

Yes we do!
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Well, the 18z looks better for Bermuda, but it is all a long way out.

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Quoting Jeff9641:
fish storm

fish storm


Holy mackerel!!!!!


Are you all seeing this???????
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880. xcool
GFS tendency TOO overdo troughs & therefore recurve storm JMO
Member Since: September 26, 2009 Posts: 2 Comments: 15684
876. IKE
As Harry Caray would say when an opposing player belted one 450 feet....it might be...it could be....it is....a fishie...

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting Portlight:


The outpouring of generosity from the blog community in support of our relief efforts after hurricane Ike ...
Absolutely.... prolly the only non-TC event on the list...
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Quoting Portlight:


The outpouring of generosity from the blog community in support of our relief efforts after hurricane Ike ...


Talked to SJ yesterday and reminded him about the Krystals. He threatened to curse me out. LOL That is the kind of stuff we need to do again so people can get involved.
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872. IKE
264 hour GFS should lead to numerous fights over whether it's a fish or not....

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting lahcuts:
Do not quite understand where Dr Masters is coming from. In the post Katrina days, the implications relative to global warming were that it was possible that global warming could be responsible for the increased hurricane activity although on several occasions he stated that there was no proof of such a relationship and that natural variability could account for the increased activity. In today's blog he states "Computer simulations of a future warmer climate generally show a reduction in global number of tropical cyclones (though the strongest storms get stronger), and it is possible we are seeing a preview of that future climate. Or, this year's quietness may simply be natural variability."

The problem with models is that they show you what you want to see - for good reason. Unless you understand and mathematically define EVERY variable that is associated with climate, or whatever it is that you are modeling, you do not have a model that can predict. At best, it can be directionally correct some, most, a few times. Look at the models used for predicting the path of a huricane. Some models show the exact opposite of what other models show and in general are all over the map. The differences between these models demonstrate that not all is understood about the nature of a hurricane. The conical shape shown for the path is a statistical best fit of all the "good" models. Another observation - if the models can be so different while a hurrican is in progress, why should one take a model's suggestion as to what hurricains will do several years out into the future. I will wait for a better understanding, better models, before making judgement as to future weather.

Dr. Frank Stuchal
I'm not sure how closely you have been following the blog since 2005, but I do know there's been quite a bit of discussion here of Landsea et al's work which talks about the reduced # of hurricanes under a global warming scenario. And the discussion was introduced by Dr. Masters' own blog on Landsea's findings. I have a hard time agreeing that a scientest should continue to uphold old theories in the face of evidence that suggests those theories are flawed. So I'm not quite certain why you feel the Dr. is somehow at fault here, or that he should not refer to the latest findings in his writing.
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Quoting IKE:


Most overused in 2010....

(1)Flagged and reported.
(2)Just minus him.
(3)Stick him on ignore.
(4)Teh.
(5)Just wait til.....
(6)Next week...


Don't forget:

_____ is a fighter/can still surprise us/can't be counted out yet/may have a few tricks up its sleeve

That looks like a TD/TS/Hurricane to me

pre-9xL/TD#/Bonnie/Colin/Danielle

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867. xcool


XXXTD5
Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting Waltanater:
Andrew had an unconfirmed gust of 212 mph but the thing broke. They later tested it with the same make and model and found it was only 186 mph! Still high. There was a rumor shortly after it hit that an x-marine had clocked a wind speed of 254 mph using some special instrument, but that also broke. That speed is about a 1/3rd the speed of sound. Again, it falls as a rumor, just like the # of casualties in South Florida from Andrew.


There was a rumor of that? People spreading rumors that 2,000 people died or something?
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862. xcool
Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting ElConando:
212mph! My goodness. Is that the highest recorded gust from a land falling cane in America? Anyone know?
Andrew had an unconfirmed gust of 212 mph but the thing broke. They later tested it with the same make and model and found it was only 186 mph! Still high. There was a rumor shortly after it hit that an x-marine had clocked a wind speed of 254 mph using some special instrument, but that also broke. That speed is about a 1/3rd the speed of sound. Again, it falls as a rumor, just like the # of casualties in South Florida from Andrew.
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Quoting IKE:


Most overused in 2010....

(1)Flagged and reported.
(2)Just minus him.
(3)Stick him on ignore.
(4)Teh.
(5)Just wait til.....
(6)Next week...


You forgot _____caster fill in the blank
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839. You made a funny!
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856. IKE
Quoting BahaHurican:
Vote for the president who keeps hurricanes off shore.... would lose the Wundervote, right? .... Right....

[Sorry, too much old school Bill Cosby.... lol]


He wouldn't stand a chance on here.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting Cotillion:
TS Chris from 2006.

That's what you call being sheared and somehow managed to get loadsa blog comments.

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Quoting BahaHurican:
Since things are relatively slow, what about a "Legends of the Wunderblog" runoff? Nominate the three or five top tropical events that typify Wunderblog history or lore. The main requirement would be that the event has to have happened since the blog happened, and it has to have entered the "history" or collective memory of the blog as a notable event.

I nominate

1)Hurricane [in the post season] Karen of 2007
2)Wilma
3)?? still thinking.... maybe Felix?

Anybody else has suggestions?


The outpouring of generosity from the blog community in support of our relief efforts after hurricane Ike ...
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Quoting DestinJeff:


No matter what your slant ... you have to appreciate that kind of satire. Funny.


I'm kinda diggin' the irony myself...
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Quoting BahaHurican:
No, but who really BELIEVED the models when they started turning Ike SW??? I was dead sure we were going to get a serious blow all the way up the Bahamian chain from IKE... I mean reamed a new one... We've got a NW passage and a NE passage... after Ike we would have had a Centre Passage.... lol



The models had a good time with this one. Had it heading to the mid Atlantic. Then Bahamas and Fla and then you know the rest. It was a crazy time.
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847. IKE
Quoting DestinJeff:


Flagged and reported. Stay on topic please, this is a weather blog. If you want to make commentary on politics, perhaps start your own blog.

It easy. And free.


Most overused in 2010....

(1)Flagged and reported.
(2)Just minus him.
(3)Stick him on ignore.
(4)Teh.
(5)Just wait til.....
(6)Next week...
Member Since: June 9, 2005 Posts: 23 Comments: 37858
11 so far. Maybe I'll repeat since we are on a new page:

Quoting BahaHurican:
Since things are relatively slow, what about a "Legends of the Wunderblog" runoff? Nominate the three or five top tropical events that typify Wunderblog history or lore. The main requirement would be that the event has to have happened since the blog happened, and it has to have entered the "history" or collective memory of the blog as a notable event.

Nominated so far:

1. Karen 2007 "never say die"
2. Dolly 2008 "no closed low"
3. Wilma 2005 "the definitive pinhole eye"
4. Dean 2008 "is that cat 5 landfall????"
5. Ernesto 2006 "yes it is; no it's not"
6. Katrina 2005 "StormTop said it would hit NOLA"
7. Marco "World's Smallest 'cane or Largest Tornado"
8. Humberto 2007? "Talk about explosive cyclogenesis"
9. Ike 2008 aka "Ike Jr."
10. Gustav 2008 "I can fake u out"
11. Fay 2008 "Florida vacation"

Anybody else has suggestions?
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Quoting DestinJeff:


Flagged and reported. Stay on topic please, this is a weather blog. If you want to make commentary on politics, perhaps start your own blog.

It easy. And free.

Well, I have one also to help clarify things.

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841. xcool




Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting IKE:


It's Obama's fault the season is in snooze mode.
Vote for the president who keeps hurricanes off shore.... would lose the Wundervote, right? .... Right....

[Sorry, too much old school Bill Cosby.... lol]
Member Since: Posts: Comments:

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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