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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oops :p double post
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Quoting Levi32:
Check out how cold the SSTs are off the west US coast.




wow what dos that mean for us??? all so is it me or dos it seen that La Niña is weaking some?
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Quoting mrsalagranny:
Hey Tornado.How are you tonight?


pretty well, how are you?

we had a funnel cloud about 20 miles from my house today, here is a link to a picture and storm report: link
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1385. pottery
Quoting robj144:
Taz always refers to modes. Are there modes of models, or just models?

Taz has a unique way with spelling.
Modes = Models.
Member Since: October 24, 2005 Posts: 0 Comments: 24369
Quoting BahaHurican:
Charlie et al were before the 2005 season. Pple have different expectations of an "active" season now....


It's really unfortunate and in my opinion, media driven. After 04 it seemed like the thing to do, cause that is where the media was. In 05, it was like hurricrack.

I remember Ernesto, fire it was supposed to be, had the chance too, good thing it didn't take it. The media BOOM BOOM TS ERNESTO BOOM BOOM, winds at 45mph, ummm huh?

This year and years to follow are going to be the year of the forecaster, IMO.
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1383. scott39
Quoting Levi32:


Possible, but we'll have to see. It may be a close call on whether it actually re-emerges over the gulf waters or stays inland. Kind of a watch and see situation.
Thanks
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1382. pottery
Quoting SLU:


That's good. So no more 95-97 degree days again?

Today Max was 93f.
So,yeh, a drop...
Member Since: October 24, 2005 Posts: 0 Comments: 24369
1381. robj144
Quoting Levi32:


I looked and it's not entirely clear. The base climatology appears to be from 1985-1993 but then in 1996 they also started using nighttime SST data that was more reliable. The maps are generally in good agreement with the other NOAA anomaly maps so they are accurate.


It's only based on 8 years? That's kind of weird... there should be a standard.
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1380. Levi32
Quoting scott39:
Levi, Are you seeing a possible redevelopement of XXTD5 early next week?


Possible, but we'll have to see. It may be a close call on whether it actually re-emerges over the gulf waters or stays inland. Kind of a watch and see situation.
Member Since: November 24, 2005 Posts: 635 Comments: 26652
1379. robj144
Taz always refers to modes. Are there modes of models, or just models?
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1378. JLPR2
I see this is what everyone is looking at tonight.

GFS 18z


ECMWF 12z


It's so far out! But seeing so much agreement between two of the big models is interesting.

Oh and by the way, hello again everyone!
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1377. Levi32
Quoting robj144:


How far back does it go? Another words, over what years is the average normal temp. calculated?


I looked and it's not entirely clear. The base climatology appears to be from 1985-1993 but then in 1996 they also started using nighttime SST data that was more reliable. The maps are generally in good agreement with the other NOAA anomaly maps so they are accurate.
Member Since: November 24, 2005 Posts: 635 Comments: 26652
Nah. Quite a few others still around.
Member Since: October 25, 2005 Posts: 19 Comments: 22293
1375. ycd0108
Thanks Levi and Pottery
Guess we are the only ones up now
Shhhsh - they are light sleepers
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Quoting tornadodude:
hey guys
Hey Tornado.How are you tonight?
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Quoting KanKunKid:


Charlie hit 10 miles from my house in Cape Coral. I felt the walls shake in my house. Worst part (made the most damage $$$) were the vortices (tornadoes) embedded in the storm. We had 135 mph straight winds, but in CC, one street had major damage (especially pool cages crumpled like a grade school love note) while the next street over was untouched. Looking up you could see blue sky. It was a strange Hurricane, but it kicked our butts but good. They said it would hit us, then....oh! No! It's going to Tampa, Cat2 or 3. People who went to Tampa to avoid Charlie came back then...Oh! No! It's coming ashore in Lee county headed for Charlotte county. The people who came back said oh **** (poop) were face to face with it. Nice call! It hit and knocked out power as a Cat4 then 6 hours later, the internet went out (had 2000+ hits on web cam watching porta pottys flying over 100 mph!) "C" storm, born in El Caribe and grew from 2 to 4 in under 3 hours.
Fond memories. I bought a battery fan afterward and always have it with me, in season. Charlie was a late August event. Nobody said it was strange back then, so what is strange now?
Charlie et al were before the 2005 season. Pple have different expectations of an "active" season now....
Member Since: October 25, 2005 Posts: 19 Comments: 22293
1372. scott39
Levi, Are you seeing a possible redevelopement of XXTD5 early next week?
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hey guys
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1370. SLU
Quoting pottery:

We have been getting south and west winds as well.
But apart from the humidity, the temps feel OK.


That's good. So no more 95-97 degree days again?
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1368. robj144
Quoting Levi32:


It's the SST anomalies so yes...anomaly relative to climatology.


How far back does it go? Another words, over what years is the average normal temp. calculated?
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Quoting Drakoen:
GFS shows a very high amplitude wave emerging off the coast of Africa next week:



We'll see what this C-Atl trough does, should be out be then, it's a strong one though.
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1366. Levi32
Quoting kmanislander:
Well, so long for tonight all.

Will be back tomorrow. Have a great evening.


Night Kman.
Member Since: November 24, 2005 Posts: 635 Comments: 26652
1365. pottery
Quoting kmanislander:
Well, so long for tonight all.

Will be back tomorrow. Have a great evening.

Good Night, Kman.
Member Since: October 24, 2005 Posts: 0 Comments: 24369
Quoting kmanislander:


I am sure they do. Problem is though you have to take a shoot from around the root of an existing tree and legend has it that you have to plant the shoot in the same compass direction as the root of it when cut from the tree otherwise it will not take.

Sounds like hocus pocus but there you have it.

I roast them in the oven at 400 degrees for an hour then let them sit in the heat for another hour or two.

Remove, peel off the skin, slice and spread with butter. Alternatively, slice thin and fry as a chip. Sprinkle with sea salt and enjoy.


Depends on where in Florida. I've been told they will only able to grow South of Lake City. I tried to grow a breadfruit tree in the panhandle but it just gets too cold up here in Winter time for them to grow since up here, we always have a couple below freezing days every year....bummer huh:0
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1363. scott39
Quoting mrsalagranny:
I know, me too.If it does redevelop how strong do u think it will be? I hope just a rain maker.
Maybe a weak TS, and thats a stretch. if the L developes, I would think it would be too close to land to be anything more.
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1361. pottery
Quoting ycd0108:
Levi:
Uh hu. That's me in the corner. What do these low temps (SST N.E.Pac.) mean for us?

Tazmanian posted a Weather Warning for high elevations in the Rockies, earlier.
Heavy snowfalls expected...
Member Since: October 24, 2005 Posts: 0 Comments: 24369
Well, so long for tonight all.

Will be back tomorrow. Have a great evening.
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Quoting HadesGodWyvern:
Japan Meteorological Agency

EXTRATROPICAL LOW, FORMER DIANMU (T1004)
43.0ºN 151.0ºE - 998 hPa

Low Position
===================
Sea East of Japan moving east northeast at 35 knots
Another 1 bites the dust. So now practically nothing globally.

This is pretty amazing.
Member Since: October 25, 2005 Posts: 19 Comments: 22293
1357. Levi32
Quoting ycd0108:
Levi:
Uh hu. That's me in the corner. What do these low temps (SST N.E.Pac.) mean for us?


It explains the record cold summer for southern California, and it's also something that favors a pattern that favors hurricanes making landfall in the US. It can set up the ridge over the northeast US which tends to keep storms recurving.
Member Since: November 24, 2005 Posts: 635 Comments: 26652
Quoting scott39:
Some models are showing developement, if the low is pushed back out in the GOM S of us. I will believe it when I see it!
I know, me too.If it does redevelop how strong do u think it will be? I hope just a rain maker.
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Quoting KerryInNOLA:
Dr Wouldlowfecer stated yesterday that this hurricane season is turning out to be a quiet one. He does not expect any major hurricanes for the rest of the season."I wouldn't drop my guard yet, but I would start lowering it" he was heard to say.


Dr who ??. Never heard of him.
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1354. Levi32
Quoting robj144:


What is the relative to... the average historical SST?


It's the SST anomalies so yes...anomaly relative to climatology.
Member Since: November 24, 2005 Posts: 635 Comments: 26652
1353. ycd0108
Levi:
Uh hu. That's me in the corner. What do these low temps (SST N.E.Pac.) mean for us?
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1351. scott39
Quoting mrsalagranny:
Oh I didnt see channel 15 news update.Ill watch it at 10:00 and see what they say Thanks.Channel 10 said they may have to up our chance of rain up to 90% on Monday.
Some models are showing developement, if the low is pushed back out in the GOM S of us. I will believe it when I see it!
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1350. robj144
Quoting Levi32:
Check out how cold the SSTs are off the west US coast.



What is the relative to... the average historical SST?
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1349. pottery
Quoting SLU:


LOL

Up here it's been very hot and dry this week. The tradewinds are gone. Winds blowing lightly from the WEST all day .. bad omen. I doubt that's going to help the situation with the warm ocean temperatures.

We have been getting south and west winds as well.
But apart from the humidity, the temps feel OK.
Member Since: October 24, 2005 Posts: 0 Comments: 24369
1348. Levi32
PDO expected to stay negative for at least the next year.

Member Since: November 24, 2005 Posts: 635 Comments: 26652
Quoting scott39:
Its coming back around to get us again. LOL
It's already here...just walked the son, wife and grandbaby to the car and heard it coming down the street towards us. Unfortunately didn't make it back up to the house in time...LOL
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1346. Drakoen
GFS shows a very high amplitude wave emerging off the coast of Africa next week:

Member Since: October 28, 2006 Posts: 57 Comments: 30556
Quoting geepy86:
Thanks fo the info Kman. My moto is if I can't eat it I'm not planting it. Someday I will have a breadfruit tree. Right now I couldn't buy a rain shower if I tried. Some are so close but not here.


It is a great tree to have. Once established it will produce more than once each year. Watch you waist though, it is food that you will wear if you enjoy it too much LOL
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1344. scott39
Quoting Levi32:
Check out how cold the SSTs are off the west US coast.

Thats crazy cold
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Quoting scott39:
I didnt hear that, but I saw channel 15 at 5pm, and he said the models are showing it loop back to us. What it does after that is still up in the air.
Oh I didnt see channel 15 news update.Ill watch it at 10:00 and see what they say Thanks.Channel 10 said they may have to up our chance of rain up to 90% on Monday.
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1342. SLU
Quoting pottery:

Again this afternoon.
Typical "back-in-times" wet-season weather.
Everything is nice, except the MUD!!!


LOL

Up here it's been very hot and dry this week. The tradewinds are gone. Winds blowing lightly from the WEST all day .. bad omen. I doubt that's going to help the situation with the warm ocean temperatures.
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Quoting pottery:

I'll swap you 2, for a shower of rain..


Done LOL.
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1340. Levi32
Check out how cold the SSTs are off the west US coast.

Member Since: November 24, 2005 Posts: 635 Comments: 26652
1339. geepy86
Thanks fo the info Kman. My moto is if I can't eat it I'm not planting it. Someday I will have a breadfruit tree. Right now I couldn't buy a rain shower if I tried. Some are so close but not here.
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Since the tropics are quiet (as of now)figure I ask a preparation question. My old standby portable TV will not receive the new digital signals. I bought a portable digital set, but could not get signals in my house and had to take it back. Has anybody found a good sensitive portable TV that would be useful during a hurricane (low power consumption would be good)?
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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.