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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1638. b4dirt
Storm is that a bermuda high forming?
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Quoting MahFL:
exTD5 will prolly suck up more moisture from Mobile Bay, also the original track way north in LA amd MS seems to be pretty much history.
I remember Fredrick in 1979 when it pulled the water from Mobile Bay.
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1636. WxLogic
Good Morning...
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1635. MahFL
I actully see banding now on the radar on the SW side.
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Quoting homelesswanderer:


I remember watching the storm near Puerto Rico, I think. She would flair up all night and strip her clothes off during the day. Lol. Don't remember which one it was though.


Erika?

or Ana? Both did roughly the same sorta thing.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
1633. MahFL
exTD5 will prolly suck up more moisture from Mobile Bay, also the original track way north in LA amd MS seems to be pretty much history.
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Quoting BahaHurican:
U know, I don't remember what happened in the Tropical Atlantic last year...

EDIT: Except Fred.


I remember watching the storm near Puerto Rico, I think. She would flair up all night and strip her clothes off during the day. Lol. Don't remember which one it was though.
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Yeah, that little risidual swirl that used to be TD-5 is approaching Mobile. It better hurry up and move through because I need to fire up the smoker in a few hours.
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Quoting StormW:


I'll give ya a hint...the CMC on those maps, has outperformed the other two by a long shot.


And the CMC at the deep layer doesn't look good.

It won't show it on the model as it doesn't pick it up on the SLP or 850Vort, but yeah.

In fact, the way it's positioned, almost reminds you of a certain storm a couple of years ago.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
BRB
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Quoting StormW:


We had 9-3-2 in a El Nino year.
Good morning Storm.Good to see you.I have the most ominus clouds over me this morning.I would take pics but dont know how to work the new camera.LOL
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Getting more coffee, then reading back to see what info I've already missed.

BTW - Morning, everyone!
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Quoting StormW:


We had 9-3-2 in a El Nino year.
True, but not really "legendary". 2006 wasn't that different #-wise, 10-5-2.
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Oh, I see I can't post fast enough this morning. Need more coffee.
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Quoting StormW:


That is the steering layers forecast out to 144 hours. What it's saying is..."forget about fish".

You can see it better here:

PSU


You mean for the GFS estimated storm?

Looking at middle/deep considering the potential intensity? Seems to be a fair bit of divergence between the three at deep layer.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Storm, you know we are always curious when you only post a graphic - LOL.
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Quoting StormW:


That is the steering layers forecast out to 144 hours. What it's saying is..."forget about fish".


Ahh. OK. Thanks. I think? Lol.
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U know, I don't remember what happened in the Tropical Atlantic last year...

EDIT: Except Fred.
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The southern Caribbean looks pretty active this morning, any model support for the area near Panama?
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1615. Keys99
Quoting StormW:
Anyone curious about this?




I'am What is it Showing as the flow direction?
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Quoting StormW:
Anyone curious about this?



I would be if I could see it. Lol. Looks like a storm over NOLA. Or is that td5?
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Quoting StormW:


As far as?


Pertaining to the Wunderblog legendary moments that Baha is carrying out.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Funny how 2009 did not capture anyone's attention, really.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Quoting StormW:


Good morning Stef!


Good morning Storm! :)
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Quoting IKE:
NOGAPS has a strong vorticity heading for the African coast in 144 hrs./6 days...link. But it looks like it's heading it off pretty far north, in agreement with the GFS and ECMWF.




I see what you're talking about but it's pretty void of convection for now.
Hey, one can always hope... lol... with the high set up the way it is, I really wouldn't expect anything except a NW/NNW track with that... at least until Monday.
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Quoting calder:


Not sure reassure is the right word here?!


Lol. No he got it right.
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Nominations for Legends of the Wunderground are now closed. Our nominations are as follows:

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."; "Beeline for South Florida! ... NOT"
14. Portlight 2008 formation "We are the Blog"
15. Marco 2008 "World's Smallest 'cane or Largest Tornado"

These are currently listed in chronological order.

I'll figure out how to do the voting thing in a few [need coffee]. I figure voting from 8 a.m. EDT to 8 p.m. CDT? Do I need to keep the poll open later? lol
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1601. IKE
NOGAPS has a strong vorticity heading for the African coast in 144 hrs./6 days...link. But it looks like it's heading it off pretty far north, in agreement with the GFS and ECMWF.


Quoting BahaHurican:
Ike, look at 10N 30W. That's where the latest Twave is... and it's likely to dip a little below 10N before it rounds that high. After that we'll see.... That's my best hope right now for something firing up between now and Sunday... lol I don't expect much out of former TD5 or the trough off the E CONUS....


I see what you're talking about but it's pretty void of convection for now.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
MAYBE WE WILL HAVE A BIG NOVEMBER AND MAYBE DECEMBER IF THERE ARE HIGH WATER TEMPS AND WIND SHEAR IS LOW WE MAY SEE A STRONG SEPTEMBER AND OCTOBER AS WELL PEOPLE DONT BE NOT ON YOUR GUARD CAUSE REMEMBER FOR A 3 YEAR PERIOD FROM 05-08 WE HAD A STRONG TS OR A HURRICANE IE OPHELIA
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Ike, look at 10N 30W. That's where the latest Twave is... and it's likely to dip a little below 10N before it rounds that high. After that we'll see.... That's my best hope right now for something firing up between now and Sunday... lol I don't expect much out of former TD5 or the trough off the E CONUS....
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1597. calder
Quoting MahFL:
StormW, please re-asssure us all the tropics will explode soon.....thanks.


Not sure reassure is the right word here?!
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Oh excuse me GOOD MORNING all very humid here this morning in z-hills fl
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1595. IKE
Wide view of the ATL. One thing I notice is the sun reflecting off of the dust off Africa....




Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting BahaHurican:
LOL.... there are a few of us left.... lol I kinda miss lefty [never thought the day would come when I would say that.... lol] And that graupel thing is why I have a soft spot for TC Felix... that was one amazing little storm...



Just because we ain't a postin doesn't mean we ain't a readin.
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Quoting aquak9:
baha- the night we followed recon on felix- from around 10pm to 2am- we were here, dropping our jaws and saying OMG...that was a most intense night here on the blogs.

I think I chewed off every last fingernail and toenail. And knowing LRandyB was heading IN, after Felix spat the NOAA hunter OUT...

then there was LRandyB's video afterwards. whoa.
Yeah.... then the other thing I remember is that persistent Wward trek. Nobody could believe it would just keep going like that... not really gain any latitude to speak of.... actually brushed the ABC islands down there near the SA coast...


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Quoting aquak9:
Baha- probably no one here remembers tartin' and twinkin' with Leftyy...

or the night we all said "WTH is graupel?"


I remember the graupel (though I was lurkin' those days). Everyone was stunned with the 189mph wind reading or whatever it was.

One nasty storm.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Quoting BahaHurican:
LOL.... there are a few of us left.... lol I kinda miss lefty [never thought the day would come when I would say that.... lol] And that graupel thing is why I have a soft spot for TC Felix... that was one amazing little storm...


I have been here awhile and mostly lurk, but i rem. leftyy420 and still chat with him on another blog.
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1590. MahFL
ex TD5 does indeed seem to be getting stronger overland, most odd.
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1589. aquak9
baha- the night we followed recon on felix- from around 10pm to 2am- we were here, dropping our jaws and saying OMG...that was a most intense night here on the blogs.

I think I chewed off every last fingernail and toenail. And knowing LRandyB was heading IN, after Felix spat the NOAA hunter OUT...

then there was LRandyB's video afterwards. whoa.
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Quoting StormW:
Good morning all!


Morning Storm.

---

On another note, looks like Bradley quit as USA coach - onto manage Villa with Lerner. Funny, considering Birmingham (albeit AL) was mentioned yesterday.

---

As the UKMET's tropical guidance only goes out for 3 days, might see if they latch onto to the system off Africa by Sun/Mon (though, not sure why they're so respected; they're not particularly here).
Member Since: August 23, 2008 Posts: 7 Comments: 5300

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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.