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 DestinJeff:
One last thing before I go ....



Peace out, folks.

You might want to patten that its become your signature post now
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Quoting DestinJeff:
One last thing before I go ....



Peace out, folks.



Enough. Put on ignore.
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Quoting BahaHurican:
Hey, I missed a page because I went out for a while.

I'll repeat for those who might have missed earlier:

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. Nominations close at 7 a.m. tomorrow.

Nominated so far:
Legends of the Wunderground

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

Anybody else has suggestions?


Felix 2007
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1184. Drakoen
Quoting Levi32:
The tropical wave over Nigeria has the look of one that will cause trouble. For the past 48 hours it has exhibited impressive mid-level turning. This could be the first one that won't take much time to develop after leaving Africa. It will exit in 5-6 days.



Supporting graphic:

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Quoting Levi32:
The tropical wave over Nigeria has the look of one that will cause trouble. For the past 48 hours it has exhibited impressive mid-level turning. This could be the first one that won't take much time to develop after leaving Africa. It will exit in 5-6 days.

Yup, it's the one that the GFS consistently develops. The CMC and ECMWF have also jumped on.
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Pink is Severe Heat Warning
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firecane "Hate to be captain obvious but when the TWO says 0% chance of development...isn't that like kind of like having braille on the drive thru ATM's?

1156 dsenecal2009 "The NHC changed their criteria, starting this year. I believe this is an improvement, because...it certainly highlights what Patrap and other New Orleanians are experiencing right now."

So is that a 0% chance that the Saints will lose? or a 0% chance that the Saints will win?
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1179. pottery
Quoting DestinJeff:
One last thing before I go ....



Peace out, folks.

A picture of the Matterhorne?
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1177. pottery
Quoting blsealevel:

ya doing good potpot i can take it lol

:):)
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Quoting pottery:

heheheh
Yeah, I know.
Just messing with his head a little.
He knows I dont mean it.
(I hope)

ya doing good potpot i can take it lol
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1174. pottery
Quoting BahaHurican:
Why does that not surprise me.... lol

Sounds like an excuse to attend Carnival every Feb....

Yeah! A good one too!
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1173. pottery
Is there a Program I can install, that will read the posts on this blog, and turn them into Audio?
Would make fine Radio you know.
A man could be eating and stuff, while...
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Quoting Levi32:
The tropical wave over Nigeria has the look of one that will cause trouble. For the past 48 hours it has exhibited impressive mid-level turning. This could be the first one that won't take much time to develop after leaving Africa. It will exit in 5-6 days.


Look at all that moisture over the southern Sahara too. That could keep SAL outbreaks from occuring ahead of it.
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Iowa is going through extreme weather conditions this week:
Excessive Heat Warning
URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
256 PM CDT THU AUG 12 2010

...DANGEROUS HEAT AND HUMIDITY THROUGH FRIDAY...



.A STAGNANT WEATHER PATTERN WILL KEEP THE EXCESSIVE HEAT AND HUMIDITY OVER THE AREA THROUGH FRIDAY. AFTERNOON AND EARLY EVENING TEMPERATURES IN THE LOWER TO MID 90S AND HIGH HUMIDITY LEVELS WILL RESULT IN A HEAT INDEX OF 105 TO 115. THERE WILL BE NO RELIEF AT NIGHT WITH HEAT INDEX VALUES REMAINING AT OR ABOVE 75. THESE PROLONGED CONDITIONS MAY BE LIFE THREATENING FOR ANYONE WORKING OUTDOORS OR WITHOUT AIR CONDITIONING.
IowaCityForecast
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believe its still stationary below gulfport/biloxi.. anyone believe it would move inland or stay out in the water?
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1169. Patrap
Member Since: July 3, 2005 Posts: 426 Comments: 128636
Quoting Levi32:
The tropical wave over Nigeria has the look of one that will cause trouble. For the past 48 hours it has exhibited impressive mid-level turning. This could be the first one that won't take much time to develop after leaving Africa. It will exit in 5-6 days.




Wouldn't worry about it. Most waves that pass over Nigeria have their identity stolen almost immediately.
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Quoting pottery:

The young man was a-courtin' a Trini Babe.
Why does that not surprise me.... lol

Sounds like an excuse to attend Carnival every Feb....
Member Since: October 25, 2005 Posts: 19 Comments: 22318
1166. pottery
Quoting doorman79:


lol, you are gonna tick him off. the three things u never mess with a new orleans man about is his food, his beer(dixie) or his saints joke

heheheh
Yeah, I know.
Just messing with his head a little.
He knows I dont mean it.
(I hope)
Member Since: Posts: Comments:
1165. Levi32
The tropical wave over Nigeria has the look of one that will cause trouble. For the past 48 hours it has exhibited impressive mid-level turning. This could be the first one that won't take much time to develop after leaving Africa. It will exit in 5-6 days.

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Quoting DestinJeff:


I've seen at some drive thru fast food they have a sign that says "braille menus available upon request" ... always found that odd.

Hey.. I had to post it.. lol
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Quoting Patrap:

T'storms are firing up.. gotta keep watching..
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1161. Patrap
Well dat just bites big time.
Member Since: July 3, 2005 Posts: 426 Comments: 128636
1159. pottery
Quoting BahaHurican:
Hey, I missed a page because I went out for a while.

I'll repeat for those who might have missed earlier:

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. Nominations close at 7 a.m. tomorrow.

Nominated so far:
Legends of the Wunderground

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

Anybody else has suggestions?
"OH NO, it's you-know-who, AGAIN"
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Quoting firecane:
Hate to be captain obvious but when the TWO says 0% chance of development...isn't that like kind of like having braille on the drive thru ATM's?


The NHC changed their criteria, starting this year. I believe this is an improvement, because while we all know it's no threat as a tropical system that will make landfall for 48 hours (this is why it's 0%), it certainly highlights what Patrap and other New Orleanians are experiencing right now.
Member Since: Posts: Comments:
Hey, I missed a page because I went out for a while.

I'll repeat for those who might have missed earlier:

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. Nominations close at 7 a.m. tomorrow.

Nominated so far:
Legends of the Wunderground

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

Anybody else has suggestions?
Member Since: October 25, 2005 Posts: 19 Comments: 22318
1152. Patrap
Member Since: July 3, 2005 Posts: 426 Comments: 128636
1150. pottery
Quoting blsealevel:

ah shaa it not dat hard ta understand you know

What?
Trying to whack a ball out of the park with a club, while being jumped on by a group of armoured 300lb ruffians is easy to understand?

Or am I confused?
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1147. flsky
Quoting spathy:



Just came in from the dock - Venus is very bright above the moon, but Mars and Saturn remain very faint. I think I might have seen Spica, but not sure. I think last year there was actually a "smiley face" in the sky from this formation. Fun stuff!
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Hate to be captain obvious but when the TWO says 0% chance of development...isn't that like kind of like having braille on the drive thru ATM's?
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Quoting pottery:

Never could understand Baseball..........

heheheh

ah shaa it not dat hard ta understand you know
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1143. pottery
Quoting LoneStarWeather:

You ain't right, Pot. :)

I try, though.....
:)
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Quoting robj144:


Are you still down 10? :)


Yup
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1140. Drakoen
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From Accuweather.com

Link
Member Since: July 2, 2009 Posts: 0 Comments: 2811
1138. robj144
Quoting Patrap:
Who Dat..?

97 yard Kickoff return for TD.

U betcha.


Are you still down 10? :)
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About

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