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 BahaHurican:
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. Rita 2005 "I tried to evacuate"
3. Wilma 2005 "the definitive pinhole eye"
4. Chris 2006 "Sheared again… Naturally"
5. Ernesto 2006 "yes it is; no it's not"
6. Dean 2007 "is that cat 5 landfall????"
7. Felix 2007 "graupel in the guts"
8. Humberto 2007? "Talk about explosive cyclogenesis"
9. Karen 2007 "never say die"
10. Dolly 2008 "no closed low"
11. Fay 2008 "Florida vacation"
12. Gustav 2008 "I can fake u out"
13. Ike 2008 aka "Ike Jr."
14. Portlight 2008 formation "We are the Blog"
15. Marco 2008 "World's Smallest 'cane or Largest Tornado"


Anybody else has suggestions?


16. IKE will hit SE Palm Beach County. Board up!
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1437. pottery
Quoting SLU:


I hope they are wrong. We have enough natural hazards to deal with for such small islands.

Absolutely Right.
Member Since: October 24, 2005 Posts: 0 Comments: 24026
1436. Levi32
Quoting pottery:

Tropical Storms dissipate Energy.
The energy is not going away. In fact, it can be argued that it is in fact increasing. Heat = Energy.
In Physics, 'for every action there is an equal and opposing reaction'.
So fewer storms would mean that they would need to be bigger storms.....

BRACE !!


Well, the total amount of energy contained in the earth's atmosphere can vary....that's how we get global temperature swings. Lower that total energy and you generally get weaker storms. Hurricanes are used to balance the earth's heat budget, so you can also get a reduction of storms simply by decreasing the difference in temperature from the equator to the poles, which also routinely goes through swings.
Member Since: November 24, 2005 Posts: 635 Comments: 26547
1435. pottery
Quoting mrsalagranny:
I agree. Noone can say for certain that the season is gonna start at any certain time.Climatology they can say it should.But only Mother Nature says when.

Keep in mind that Climatology is basically a Historic Record.
We have never been in this situation before.......
The heat records that have been set, over land and sea, this year, make a mess of all that.
Member Since: October 24, 2005 Posts: 0 Comments: 24026
Quoting mrsalagranny:
She is doing wonderful.Thank you for remembering.God has really touched her body.


You are very welcome! AND PRAISE GOD!!!
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Quoting txsweetpea:

Hey! How are things with your mom?
She is doing wonderful.Thank you for remembering.God has really touched her body.
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Quoting 70114weather:
Eagle...was just looking at that image. TD5 was the little storm that could...and would not die.


Yes...I was looking at some models earlier that still depicted it making a 360 before jetting off to the NE...we will see.

v/r

Jon
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1431. SLU
Quoting pottery:

I think that "more severe weather" is how they put it.
Drier dry seasons, wetter wet seasons.
But it will take a while to reach any kind of equilibrium I guess.
Lots of ups and downs to be expected.


I hope they are wrong. We have enough natural hazards to deal with for such small islands.
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1430. pottery
Quoting BahaHurican:
Certainly not in the islands. We used to max out at 89, 90, even this far north.

And now ?
Member Since: October 24, 2005 Posts: 0 Comments: 24026
Quoting pottery:

StormW is an excellent Met.
I have a lot of respect for him, and other Mets as well.
But the fact that he (and some others) say that this season is about to explode, does not mean it is guaranteed to happen.

So far this year, many Forecasters were anticipating several Hurricanes.
Well, conditions have been against that, and as Dr. Masters says (above), there may be factors that are not well understood so far, causing a delay or perhaps even a damping effect.

We all anticipate a change soon in the existing conditions, but no guarantees are being written by anyone, I dont think.


Re thinking my 15th claim here. 3 days to clear out a big mess is looking rather slim.
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Quoting pottery:

StormW is an excellent Met.
I have a lot of respect for him, and other Mets as well.
But the fact that he (and some others) say that this season is about to explode, does not mean it is guaranteed to happen.

So far this year, many Forecasters were anticipating several Hurricanes.
Well, conditions have been against that, and as Dr. Masters says (above), there may be factors that are not well understood so far, causing a delay or perhaps even a damping effect.

We all anticipate a change soon in the existing conditions, but no guarantees are being written by anyone, I dont think.
I agree. Noone can say for certain that the season is gonna start at any certain time.Climatology they can say it should.But only Mother Nature says when.
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Eagle...was just looking at that image. TD5 was the little storm that could...and would not die.
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1426. robj144
Quoting pottery:

Tropical Storms dissipate Energy.
The energy is not going away. In fact, it can be argued that it is in fact increasing. Heat = Energy.
In Physics, 'for every action there is an equal and opposing reaction'.
So fewer storms would mean that they would need to be bigger storms.....

BRACE !!


Heat IS a form of energy. Q = m c (Tf - Ti)
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1425. SLU
Quoting BahaHurican:
Certainly not in the islands. We used to max out at 89, 90, even this far north.


wow

As a little boy growing up .. and we're talking about just yesterday here .. 85F - 86F would be the daytime high here. 90F was totally unheard of here until maybe the mid - late 90's and it's reached a point where the temperature reaches 90F even before midday nowadays. If there's no rain or not many clouds, 92F can be breached. The highest for this year so far has been 93F I believe. Perhaps the hottest ever.
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Member Since: Posts: Comments:
1423. pottery
Quoting SLU:


That's a very large and alarming jump considering that 20 years is a very small sample size as far as climatology is concerned. The experts are already warning us in the Caribbean to expect higher temps and more severe droughts in the coming decades.

I think that "more severe weather" is how they put it.
Drier dry seasons, wetter wet seasons.
But it will take a while to reach any kind of equilibrium I guess.
Lots of ups and downs to be expected.
Member Since: October 24, 2005 Posts: 0 Comments: 24026
Quoting mrsalagranny:
good evening.

Hey! How are things with your mom?
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Member Since: Posts: Comments:
Quoting mrsalagranny:
good evening.



Hey! How are things with your mom? Good I hope!
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Quoting CyclonicVoyage:
I tell ya what, that trough in the C-ATL sure cleaned the slate, lol.
There's been a lot of rain over the Sahel region where the dust originates also, which means there isn't as much to replenish what's been removed. I noticed the recent dust plume was much further north - by almost 5 degrees - than the previous outbreak.
Member Since: October 25, 2005 Posts: 19 Comments: 21485
1418. pottery
Quoting mrsalagranny:
I hope everyoe doesnt get complacit and think this year is gonna be quiet.According to StormW,the top is gonna blow off soon.I hope everyone stays alert.

StormW is an excellent Met.
I have a lot of respect for him, and other Mets as well.
But the fact that he (and some others) say that this season is about to explode, does not mean it is guaranteed to happen.

So far this year, many Forecasters were anticipating several Hurricanes.
Well, conditions have been against that, and as Dr. Masters says (above), there may be factors that are not well understood so far, causing a delay or perhaps even a damping effect.

We all anticipate a change soon in the existing conditions, but no guarantees are being written by anyone, I dont think.
Member Since: October 24, 2005 Posts: 0 Comments: 24026
Quoting pottery:

Certainly NOT.
In fact, the 'mean' has gone up 2-3 degrees in 20 years.
32 was unheard of, 20 years ago.
Certainly not in the islands. We used to max out at 89, 90, even this far north.
Member Since: October 25, 2005 Posts: 19 Comments: 21485
U guys haven't been in the main blog much today, I suppose... EVERYBODY has been saying we're likely to have a busy Sept and Oct... lol even Ike is admitting that it is possible....
Member Since: October 25, 2005 Posts: 19 Comments: 21485
Quoting txsweetpea:
Hello everyone!
good evening.
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I tell ya what, that trough in the C-ATL sure cleaned the slate, lol.
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1413. SLU
Quoting pottery:

Certainly NOT.
In fact, the 'mean' has gone up 2-3 degrees in 20 years.
32 was unheard of, 20 years ago.


That's a very large and alarming jump considering that 20 years is a very small sample size as far as climatology is concerned. The experts are already warning us in the Caribbean to expect higher temps and more severe droughts in the coming decades.
Member Since: Posts: Comments:
Hello everyone!
Member Since: Posts: Comments:
1411. pottery
Quoting SLU:


Do you ever remember it being this hot 20 or 30 years ago?

Certainly NOT.
In fact, the 'mean' has gone up 2-3 degrees in 20 years.
32 was unheard of, 20 years ago.
Member Since: October 24, 2005 Posts: 0 Comments: 24026
A slow start huh? But I believe that Sept and Oct will be very active. Storm wrote it on his blog. Everything is going to be in place. If we have no Hurricanes by Sep 15th because of dry air or a Tull then we can start talking about a bust in the forcast.

We have a long way to go. Conditions will improve. There will be hurricanes out there regardless of all the hype. Where they go depends on the stearing curents. Its a crapshoot. I love the discussion.
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I hope everyoe doesnt get complacit and think this year is gonna be quiet.According to StormW,the top is gonna blow off soon.I hope everyone stays alert.
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1408. pottery
Quoting CyclonicVoyage:
Maybe 2010 will be the year that people actually realize what kind of effect we're having and what we're changing. The thought in Dr. Masters post about fewer but, stronger storms really hits home. Less storms means more extremes until the extreme storms come to even the balance, great...

Tropical Storms dissipate Energy.
The energy is not going away. In fact, it can be argued that it is in fact increasing. Heat = Energy.
In Physics, 'for every action there is an equal and opposing reaction'.
So fewer storms would mean that they would need to be bigger storms.....

BRACE !!
Member Since: October 24, 2005 Posts: 0 Comments: 24026
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. Rita 2005 "I tried to evacuate"
3. Wilma 2005 "the definitive pinhole eye"
4. Chris 2006 "Sheared again… Naturally"
5. Ernesto 2006 "yes it is; no it's not"
6. Dean 2007 "is that cat 5 landfall????"
7. Felix 2007 "graupel in the guts"
8. Humberto 2007? "Talk about explosive cyclogenesis"
9. Karen 2007 "never say die"
10. Dolly 2008 "no closed low"
11. Fay 2008 "Florida vacation"
12. Gustav 2008 "I can fake u out"
13. Ike 2008 aka "Ike Jr."
14. Portlight 2008 formation "We are the Blog"
15. Marco 2008 "World's Smallest 'cane or Largest Tornado"


Anybody else has suggestions?
Member Since: October 25, 2005 Posts: 19 Comments: 21485
A slow start huh? But I believe that Sept and Oct will be very active. Storm wrote it on his blog. Everything is going to be in place. If we have no Hurricanes by Sep 15th because of dry air or a Tull then we can start talking about a bust in the forcast.
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Quoting HurricaneLovr75:
A slow start huh? But I believe that Sept and Oct will be very active. Storm wrote it on his blog. Everything is going to be in place. If we have no Hurricanes by Sep 15th because of dry air or a Tull then we can start talking about a bust in the forcast.


Quite a few have been writing about this delayed season. The Bulls will be out soon.
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1404. SLU
Quoting pottery:

Even when the Trades are blowing these days, they are coming off 84-85 degree sea.
Hot, damp, muggy...


Do you ever remember it being this hot 20 or 30 years ago?
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Quoting jurakantaino:
I'm glad that finally Dr.Masters, TWC, also made comments on the surprisingly slow start of the season, even with SST are a records high and "la niña" in full bloom . Is obvious that scientist are wondering "what happened with the Hyperactive season". The good Dr. gave some hints of what might be going on, but one thing is for sure tropical weather is fascinating and amateurs, experts and scientist included have lot to learn, still.
I thought the Doc pulled together and put forth some interesting hypotheses. I would be intrigued to see some studies that examine these factors to determine how valid these ideas are.
Member Since: October 25, 2005 Posts: 19 Comments: 21485
Nothing but Blobs... but lots of them :P




AOI

AOI

AOI

AOI

AOI

TS BUSTED FORECAST ALIBI
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1401. KEEPEROFTHEGATE (Mod)
Quoting Tazmanian:



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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1400. pottery
Quoting Levi32:


There is. Like I said there is more data in there just unclear how much.

SST's have been recorded for a LONG time by Mariners, the Navies of the world, in Ports, all kinds of places.
Member Since: October 24, 2005 Posts: 0 Comments: 24026
1399. Levi32
Quoting Tazmanian:



wow what dos that mean for us??? all so is it me or dos it seen that La Niña is weaking some?


1357.

La Nina is just having a small blip. It happens.

Member Since: November 24, 2005 Posts: 635 Comments: 26547
A slow start huh? But I believe that Sept and Oct will be very active. Storm wrote it on his blog. Everything is going to be in place. If we have no Hurricanes by Sep 15th because of dry air or a Tull then we can start talking about a bust in the forcast.
Member Since: Posts: Comments:
1397. robj144
Does anyone know how the SST compares to the SST of 2005 when we had three cat. 5 storms? I know SST is at record highs this year, but how much warmer are they compared to 2005. Is there a map of that?
Member Since: Posts: Comments:
Maybe 2010 will be the year that people actually realize what kind of effect we're having and what we're changing. The thought in Dr. Masters post about fewer but, stronger storms really hits home. Less storms means more extremes until the extreme storms come to even the balance, great...
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1395. pottery
Quoting SLU:


That's rather hot. For the whole year so far we've maxed out at 89 - 91F almost everyday. Cooler than you but still hotter than normal. I miss the cooling effects of lovely NE trade winds.

Even when the Trades are blowing these days, they are coming off 84-85 degree sea.
Hot, damp, muggy...
Member Since: October 24, 2005 Posts: 0 Comments: 24026
1394. Levi32
Quoting robj144:


It's only based on 8 years? That's kind of weird... there should be a standard.


There is. Like I said there is more data in there just unclear how much.
Member Since: November 24, 2005 Posts: 635 Comments: 26547
1393. SLU
Quoting pottery:

Today Max was 93f.
So,yeh, a drop...


That's rather hot. For the whole year so far we've maxed out at 89 - 91F almost everyday. Cooler than you but still hotter than normal. I miss the cooling effects of the lovely NE trade winds.
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Quoting tornadodude:


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
Wow.Nice shot of the funnel.
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1390. robj144
Quoting pottery:

Taz has a unique way with spelling.
Modes = Models.


Thanks. Microsoft Word must have a nervous break down when he types. Just kidding Taz. :)
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I'm glad that finally Dr.Masters, TWC, also made comments on the surprisingly slow start of the season, even with SST are a records high and "la niña" in full bloom . Is obvious that scientist are wondering "what happened with the Hyperactive season". The good Dr. gave some hints of what might be going on, but one thing is for sure tropical weather is fascinating and amateurs, experts and scientist included have lot to learn, still.
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oops :p double post
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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.