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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here ya go shaa; games on
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I want to watch the Saints game tonight but can't find it on our lineup. That really bites! Guess I could watch it online or something. Geez.
Member Since: September 7, 2005 Posts: 0 Comments: 274
Howdy all...
Member Since: July 30, 2010 Posts: 0 Comments: 491
Quoting OpusDei:
Hey All,
Seems like we are getting a bit of alignment of expectations for the models re what Levi32 was hinting at yesterday (GOM potential "TD5" being dropped back into gulf).
Link
Wow almost every model is hinting at it.
Member Since: September 7, 2005 Posts: 0 Comments: 274
933. xcool
DestinJeff /ha
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5 minutes with not one post...Thats what I call a dead blog!
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930. xcool
wow blog deaddd
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Quoting OpusDei:
Hey All,
Seems like we are getting a bit of alignment of expectations for the models re what Levi32 was hinting at yesterday (GOM potential "TD5" being dropped back into gulf).
Link


I heard on the news this evening from a local met'gst that we are going to have a hot weekend here in Houstoin then Monday, more into Tuesday what is left of td 5 could move this way and bring us rain.
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Hey All,
Seems like we are getting a bit of alignment of expectations for the models re what Levi32 was hinting at yesterday (GOM potential "TD5" being dropped back into gulf).
Link
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927. xcool
SPECIAL MARINE WARNING
GMZ435-455-130000-
/O.NEW.KLCH.MA.W.0115.100812T2303Z-100813T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE LAKE CHARLES LA
603 PM CDT THU AUG 12 2010

THE NATIONAL WEATHER SERVICE IN LAKE CHARLES HAS ISSUED A

* SPECIAL MARINE WARNING FOR...
VERMILION BAY OVER GULF OF MEXICO WATERS...
COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA
OUT 20 NM OVER GULF OF MEXICO WATERS...
INCLUDING VERMILION BAY...

* UNTIL 700 PM CDT

* AT 559 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF THUNDERSTORMS...PRODUCING STRONG WINDS 34 KNOTS OR GREATER
FROM 15 NM NORTHEAST OF VERMILION BAY TO 20 NM EAST OF VERMILION
BAY...OR FROM 15 NM NORTHEAST OF VERMILION BAY TO 16 NM NORTHEAST
OF MARSH ISLAND...MOVING SOUTHWEST AT 10 KNOTS.

* THESE STRONG THUNDERSTORMS WILL BE NEAR
2 NM NORTHEAST OF VERMILION BAY BY 700 PM CDT

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MARINERS CAN EXPECT GUSTY WINDS...HIGH WAVES...DANGEROUS LIGHTNING...
AND HEAVY RAINS. BOATERS SHOULD SEEK SAFE HARBOR IMMEDIATELY...UNTIL
THIS STORM PASSES.

&&

LAT...LON 2983 9193 2985 9183 2980 9181 2978 9186
2973 9185 2977 9175 2976 9163 2965 9162
2965 9157 2947 9169 2952 9178 2956 9172
2964 9191 2961 9194 2975 9220 2978 9215
2976 9209 2981 9199 2985 9196
TIME...MOT...LOC 2303Z 042DEG 11KT 2993 9192 2971 9163

$$
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926. skook
Quoting IKE:
Nice afternoon here in the Florida panhandle...only 80.2 outside. Picked up .15 of an inch of rain today.

Signed,

The blogger that only posts models that show nothing.





standard reply

Reported (for stating your thoughts and opinions)


sarcasm off.
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Looks like the North Pakistan floods will probably last longer than the Russian heat wave, since the ridge over Russia will be weakened as temperature zones shift south as fall starts but the troughs such as the one producing rainfall over Pakistan should be amplified.
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I like having a variety of different personalities on here... Not everyone forecasts a Cat 5 going over Florida and re-forming into a Cat 7 MegaCane filling the entire Gulf of Mexico.

Basically, all of the disagreement just reflects the uncertainty in the business in general and each storm individually.

When you see Ike posting one day something like, "I'm serious guys, this storm's for real." You will probably pay attention. Of course by the time Ike's said that, some of the more excitable bloggers have evac'ed to Canada. ;) JK LoL
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Xcool, Jase, Most u'd use that view for is to see if there's potential for something to form. Where it's going to end up really can hardly be verified 3 days out, much less 12...
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922. xcool
jasoncoolman2010xx .IKNOW :)
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920. xcool
trees down Pearl River Co, MS
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Hey everyone! I heard today that the remnants of td 5 could emerge back intot he gulf and head towards the Houston area. Anyone have any models suggesting this? Thanks for the help!
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Quoting Chucktown:


This potential recurve wouldn't be caused by a trough, looks like a weakness in what I like to call "the ridge bridge".


I would hate to disagree with you but in that run the 18z GFS develops a pretty strong shortwave trough coming off of canada which causes the weakness in the A/B high. Based on the look of things in that run a weaker storm would indeed continue w-wnw whereas a storm of the magnitude predicted by GFS would feel the weakness and recurve. We shall wait and see. It is still far out but with the model support from GFS, CMC, and ECMWF of a cv system forming around that time period it bears watching and development seems likely. Way too early to speculate on track
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Quoting DestinJeff:


Yeah, well, he is only posting it because it showed a fish. I'll bet if it shows a CONUS threat he'll not be so quick to post it.


lol
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If it hit Bermuda, it ain't a fish, folks.
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914. xcool
Chucktown .You're Right
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Quoting Jeff9641:
fishy
come on now Jeff, now is your cue, you have every storm, rain band and every other feature bottoming out and hitting the state of Florida, how can you even think to say fish.
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Quoting xcool:
GFS tendency TOO overdo troughs & therefore recurve storm JMO


This potential recurve wouldn't be caused by a trough, looks like a weakness in what I like to call "the ridge bridge".
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Quoting IKE:
264 hour GFS should lead to numerous fights over whether it's a fish or not....

Ike, you must have posted the wrong model, that one clearly shows something more than nothing :)
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Quoting IKE:


He use to crack me up trying to say players names like Bobby Abreu...after two cases of cold Bud Light.




GFS might be on to something and it's usual for that model to flip-flop on track that far out. It may show it heading into the GOM on the next run.

Problem is...a select few on here will jump on that GOM run and the...."it's a definite track to Florida" crowd will show up.


Maybe I should start the 'it's a definite track to Britain' crowd...

And hey Press! Lurkin' there in the shadows.
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Quoting IKE:


Most overused in 2010....

(1)Flagged and reported.
(2)Just minus him.
(3)Stick him on ignore.
(4)Teh.
(5)Just wait til.....
(6)Next week...
names created by JFV
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If the GFS pans out, could be looking at same type of track as Bill and same exact week as in 2009.
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baha- are you gonna do a blog on this?
Member Since: August 13, 2005 Posts: 163 Comments: 25732
Cotillion, I just put them in the way pple gave them to me. I'll likely reorder them by year when I post them for voting...
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897. xcool
btwntx08 GFS tendency TOO overdo troughs & therefore recurve storm
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896. IKE
I'll check back in a while.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
895. IKE
Quoting asgolfr999:


Ike you have lost your mind again!!!

Clearly S Florida


LOL...from 4,000 miles away.

How can anybody seriously say that?
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting BahaHurican:
Anyway, I'll keep this open 'til tomorrow about this time and post results in the blog then...

Added so far:

12. Chris 2006 "Sheared again… Naturally"
13. Portlight 2008 formation "We are the Blog"


Swap them around.

Portlight sounds better at 12... the 'Twelfth Man' and all...

And 13 is a good number to reflect Chris' luck.
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Quoting thelmores:


And you forgot.....

"Is that you JFV?"



LOL!!
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891. IKE
Quoting DestinJeff:



Action:
Quote
| Ignore User





That's Harry Caray. Sounds like he had had a few by that HR for Grace. I wonder what inning it was? lol.....
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Good day everyone!
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Quoting IKE:
As Harry Caray would say when an opposing player belted one 450 feet....it might be...it could be....it is....a fishie...



Ike you have lost your mind again!!!

Clearly S Florida
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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.