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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Member Since: July 3, 2005 Posts: 426 Comments: 129089
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?


How about Humberto? Talk about explosive cyclogenesis.
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Quoting DestinJeff:


Me and Dewey, I presume.

It's Dewey and I...
Member Since: August 19, 2008 Posts: 42 Comments: 6269
And their are the people like myself who have to put "disclaimer" at the beginning of their posts so that they don't get bashed beyond recognition!

It goes something like this, "....been lurking for years" or "I don't know much about tropical weather" or "please go easy on me, but"
etc. etc. etc....
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Quoting DestinJeff:


TD5 and the NHC's incredible ineptitude in tracking the actual center!

Remember that one like it was yesterday.
Um... maybe because it WAS yesterday???

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In my humble opinion, the NHC will probably regret downgrading TD5. For one thing, we now keep referring to it as "THE REMNANTS OF TD5". That uses more ink. (besides, Prince tried that... being called "the artist formerly known as Prince" and we all know how that worked out.)

If "The Remnants of TD5" or "The Storm Formerly Known as TD5" looks like it might possibly hang around for a few days, may move back into the gulf or might cause tropical rain related flooding... for the sake of our sanity PLEASE re-name the thing TD5. It would simplify things soooo much.

Next time, don't be so eager to downgrade.

(climbs off his soapbox). So there!
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Shortest blog page I've ever had. I have two bloggers showing....LOL
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Quoting MiamiThrice:


1. Katrina
2. Wilma
3. Dean
4. Karen
5. Ernesto



Isabel
Marco

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Quoting MiamiThrice:



I hate when you people bash the NHC. The people there know more about the tropics than most of you will ever dream about

You people? *snicker*

Welcome aboard... I'm assuming you're new?
Member Since: August 19, 2008 Posts: 42 Comments: 6269
Quoting AllBoardedUp:
Don't forget....
ignore him, he, she, or (fill in appropriate name)
sheesh
anything negative about TWC
link, please!
Also,
"anyone notice that wave coming off Africa" while everyone else is talking about the Cat 3,4 or 5 that is looming off the CONUS.
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Quoting DestinJeff:


Forgot this view, to really clarify things:

Diet Coke through the nose ya bum!
Member Since: August 19, 2008 Posts: 42 Comments: 6269
Quoting DestinJeff:


TD5 and the NHC's incredible ineptitude in tracking the actual center!

Remember that one like it was yesterday.



I hate when you people bash the NHC. The people there know more about the tropics than most of you will ever dream about
Member Since: Posts: Comments:
Is it also possible that you don't know as much as you think you do about the earth's climate and what is affecting it?
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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?


1. Katrina
2. Wilma
3. Dean
4. Karen
5. Ernesto
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766. BahaHurican

definately "Dolly"
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Quoting NotJFV:
you forgot... is that JFV... hmmm
Don't forget....
ignore him, he, she, or (fill in appropriate name)
sheesh
anything negative about TWC
link, please!
Member Since: Posts: Comments:
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?
Member Since: Posts: Comments:
764. xcool
THE REMNANTS OF TD5
.
SATELLITE ANALYSIS AND TRENDS...LOW LVL CENTER OF THE REMNANTS OF TD5 CAN
BE SEEN IN VIS SATL/RADAR IMAGERY JUST ESE OF SLIDELL, LA WHERE IT IS NRLY
STNRY AT THIS TIME. STRONG DIURNAL HEATING HAS ALLOWED FOR CONVECTIVE
DVLPMT TO OCCUR WITHIN SVRL BANDS THAT EMANATE OUTWARD FROM NR THE LOW
LVL CENTER WITH CELLS DVLPG OVER SE LA/SW MS BETWEEN TWO AREAS OF DECAYING
CIRRUS. PRIMARY BAND APPEARS TO BE ROTATING INLAND ACROSS SRN MS/SRN AL/SW
GA/FL PANHANDLE CURRENTLY. ADDTL CNVTN APPEARS TO BE TRYING TO FORM OVER
S CENTRAL MS TO ADD TO THE SECONDARY BANDING THAT HAS SET UP THERE AND
IN SE LA. PW VALUES REMAIN VERY HIGH..RANGING FROM 2.5-2.8 IN SOME AREAS.
.
SHORT TERM OUTLOOK VALID 21-00Z..HIGH CONFIDENCE IN SHORT TERM
OUTLOOK..BANDS SHOULD CONTINUE TO ROTATE NNWWD INTO MS/AL OVER THE
NEXT FEW HRS WITH SOME OF THE CELLS CLOSER TO THE CENTER MERGING
INTO SMALL CLUSTERS..POSSIBLY OVER OR JUST NE OF NEW ORLEANS. CELLS
WILL BE FAIRLY SLOW MOVING BUT IN GNRL SHOULD NOT BE STNRY. ON THE
W SIDE OF THE CENTER..CELLS WITHIN THE BAND WILL WRAP SWD ACROSS SW
MS/SE LA AND POSSIBLY BACK EWD ACROSS MANY OF THE SAME PARISHES THAT
RECEIVED HVY RAINFALL EARLIER TDY..MOST LIKELY TERREBONNE/LAFOURCHE/SRN
JEFFERSON/AND PLAQUEMINES PARISHES GIVEN THE CURRENT LOCATION OF THE LOW
LVL CENTER. RAINFALL RATES WILL BE HVY GIVEN DEEP MOISTURE IN PLACE..SLOW
MOVEMENT OF CELLS..AND LACK OF MOVEMENT OF THE REMNANT TD..POSSIBLY UP
TO 3-4"/HR.
.
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Quoting tkeith:
little Snookies everywhere...

Oh my gawd!

*fist pump*
Member Since: August 19, 2008 Posts: 42 Comments: 6269
Quoting FLdewey:

Good God I hope not... can imagine the runoff from a Jersey Storm.
little Snookies everywhere...
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Cloud seeding by Weather Modification Inc., paid for by insurance companies, helped to reduce the severity of storms in Canada:

Link






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Double outflow power!


Member Since: August 19, 2008 Posts: 42 Comments: 6269
Quoting Floodman:


That's the Yugo 3000, right?


Looks like its runnin on 2 1/2 cylinders.
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Quoting calder:


IMHO, (insert storm/invest name) is going to be (insert double the intensity forecast of the NHC) and going to slam into (insert 'florida')

FTW!
Member Since: August 19, 2008 Posts: 42 Comments: 6269
Quoting BahaHurican:
I assume St. Lucia? Have u got a nearest coordinates? Would be interesting to look via satellite to see what's there...


its called trade winds, they pack more punch than this years hurricane season!
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Now checking the blog for the first time today, this is the first reasonable explanation of the uncanny quiet this season has been exhibiting. Thanks Dr.Masters.
Imaging the activity that is most likely to be condensed into the last 3 months of the season.
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http://www.wunderground.com/blog/MiamiThrice/show.html

if you guys could give me feedback on my 2010 hurricane season forecast it would be greatly appreciated

repost from last page
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Quoting StormW:


Is that a pinhole eye?


IMHO, (insert storm/invest name) is going to be (insert double the intensity forecast of the NHC) and going to slam into (insert 'florida')
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747. :)
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Quoting NJ2S:


is that going to hit NJ???!!! looks awful close :(

Good God I hope not... can imagine the runoff from a Jersey Storm.
Member Since: August 19, 2008 Posts: 42 Comments: 6269
Quoting StormW:


Is that a pinhole eye?


Nic try JFV you ar re ported
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AAAaahahahahaha!
Member Since: August 19, 2008 Posts: 42 Comments: 6269
Okay kids,play nice...I'm off to see the Wizard!
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http://www.wunderground.com/blog/MiamiThrice/show.html

if you guys could give me feedback on my 2010 hurricane season forecast it would be greatly appreciated
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746. NJ2S
Quoting Levi32:
Some Canadian ensemble members still hinting.

Day 14:



is that going to hit NJ???!!! looks awful close :(
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Quoting StormW:


Is that a pinhole eye?



lol
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Quoting BahaHurican:
Taz, that tells me what happening to it but not what it IS.... lol. I didn't realize that the TWave hadn't gone into the Car but was still headed NW...




ok
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Quoting Halyn:
I'm just now reading and catching up .. but I want to support the Floodman Lovefest .. his is a voice of sanity in an insane environment (or is it the opposite ?) .. oh well .. doesn't matter .. I really miss his input when it is not present .. :)) Scarey thing is I understand everything he says .. lol. Speech .. Speech !!!


I fear for you, my friend, if everything I say makes sense...I hear that medication helps!

Thanks, by the way, to you and all my supporters...now, on to November!
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Quoting wunderkidcayman:
Tazmanian to me it look like a wave that has some vort at 850 and developing and wind shear of about 10-20 kt and decreasing with movements according to the steering maps to bee moving W-WNW



ok
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Taz, that tells me what happening to it but not what it IS.... lol. I didn't realize that the TWave hadn't gone into the Car but was still headed NW...

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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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