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 Drakoen:


Did I? The blog looks fine for me.


Must be me.
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HPC Discussion

THE GULF COASTAL REGION SHOULD REMAIN WET THIS ENTIRE PERIOD WITH
A BROAD AREA OF LOW PRESSURE IN PLACE AND POSSIBLE INTERACTION
FROM THE MID LEVEL REMAINS OF A TROPICAL DEPRESSION. ALL MODEL
GUIDANCE INDICATES THIS WITH THE GFS THE MOST AGGRESSIVE AND
PERSISTENT DEVELOPING STRONGER SFC LOW PRESSURE. WHETHER THIS IS
REAL OR A FEEDBACK PROBLEM REMAINS TO BE SEEN. EXPECT THE LATTER
AS THIS NEW VERSION OF GFS HAS SHOWN POSSIBLE HYPERSENSITIVITY TO
CYCLOGENESIS OVER SUBTROPICAL MARINE REGIONS. THUS HAVE KEPT IN A
BROAD TROF AND AREA OF LOW PRESSURE OVER THIS REGION WITH AMBIENT
HIGH PWS.


...REMNANTS OF TROPICAL DEPRESSION NUMBER FIVE...

PREFERENCE: NAM OR ECMWF

THE NAM...UKMET...AND ECMWF HANDLE THE TRACK OF THE LOW LEVEL
CIRCULATION COMPARABLY THROUGH THE PERIOD...SENDING IT ON A TIGHT
ANTICYCLONIC LOOP INTO THE FLORIDA PANHANDLE BY THE END OF DAY 3.
THE GFS STALLS IT IN THE LOOP OVER NORTHERN ALABAMA DAY 3...SO
WILL CONSIDER IT A LOWER PROBABILITY OUTLIER. THE GEM GLOBAL
PULLS THE CIRCULATION INTO CENTRAL GEORGIA BY THE START OF DAY
3...SO WILL RULE IT AN OUTLIER AS WELL.
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Quoting NASA101:


Hmmm, not sure I agree with you Sir... a strengthening cylone at 45W north of 15N will be hard pressed to hit the CONUS - that's at least What I think...!! :)


Of course not saying that it cannot happen but most in that position to curve out to sea!
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Quoting twhcracker:


i love flood! he laughs at my corny jokes :)


That and the gherkins, darlin'!
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Dr. Masters great update today. Even though we have had 3 named storms in the Atlantic thus far, I must say that for the most part all of them have been weak and struggled most of their lives. The Tropical Storm that rolled through S.Florida, I don't believe should have ever been named. Question: Do you think that there are times when storms get named, when they really shouldn't have been?
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Quoting nrtiwlnvragn:
Is it me or did 480. Drakoen 3:12 PM EDT mess up the blog?


Did I? The blog looks fine for me.
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Quoting Enigma713:

Flood, what have you been feeding everyone on the blog? Where did this love-fest come from?

~Jeffs713


I'm not sure...if I figure it out I'm putting in a patent application and looking for FDA approval!
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Quoting Levi32:


It in fact happens all the time.


Hmmm, not sure I agree with you Sir... a strengthening cylone at 45W north of 15N will be hard pressed to hit the CONUS - that's at least What I think...!! :)
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494. Pat, ROFLMBO.
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Quoting NASA101:


If this entity is already a cyclone and north of 15N around 45 West then most likely it'll recurve to sea, unless there is a strong high pressure to make it go WNW/W - but it's not common!


It in fact happens all the time.
Member Since: November 24, 2005 Posts: 628 Comments: 26460
Quoting Levi32:




If this entity is already a cyclone and north of 15N around 45 West then most likely it'll recurve to sea, unless there is a strong high pressure to make it go WNW/W - but it's not common!
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Quoting IKE:


That's what I'm getting at...it shows it as a weaker low then the former TD that is near New Orleans.

Maybe it'll show it stronger on the next run.


Lessee... for comparison:

The Euro by 240 gives it 2 closed isobars.

The GFS gives it... 4 I think.

24 hours after that it gives it 6 or 7.

So, we'll see by tomorrow's 12z run whether the Euro wants to do the same. Or earlier.
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Quoting BahaHurican:
Hmmm.... Came across this in the comments section under Dr. Klotzbach's article from the other day....

JKrob says:
August 12, 2010 at 8:36 am
PolishG asked%u2026
%u201C%u2026Then suddenly there is the same temperature difference, and hurricanes! I ask %u2014 why? The message I gathered from the PT article is because heat input has increased due to high wind speeds %u2014 and high wind speeds are due to high heat input %u2014 but, my apologies, this is exactly what Baron Mnchhausen did when getting out of a swamp by pulling his own hair%u2026%u201D

If I may, the thing that separates a mass of showers/thunderstorms from an organized tropical cyclone is the Upper-Level High (ULH) at the top of the storm. The ULH is what is driving the cyclone and causing the pressure drop at the surface. It is fed by the latent heat released from the moisture drawn up from below.

The airflow in the lower levels into an organized storm is a fairly long path, round in circles, compaired to the slightly curved path out & away from the storm at the top. The ULH is pushing the exhaust air out away from the storm faster than is being supplied from below. Since it cannot draw air from above the tropopause, it must draw (lift) air from below. This lowers the pressure at the surface since the entire column of air across a relatively broad area is being lifted.

The ability of the ULH to do this is governed by the temperature contrast from the center to the outer edges. The warmer the center of the ULH is, the greater it%u2019s %u2018pumping%u2019 action is and since this heat is brought up from the surface, the warmer the water is, the stronger the ULH can be which translates to a stronger tropical cyclone.

The upper levels if the tropical cyclones have always been neglected from monitoring mainly due to the difficulty of reaching it but I believe *that* is where the %u2018engine%u2019 of the tropical cyclone resides and everyplace else below that we look, we are just seeing the effects of the storm (low pressure, high winds, eye wall, etc.) but not the cause and that is why I think this new NASA project to discover the cyclone genesis may miss the mark because they are looking in the wrong area. I notice the NASA ER-2 (U-2) is not involved with the project.

I have more details to this genesis theory if you are interested.

Jeff



According to Chris Davis, the leader of the project, The PREDICT aircraft will be sending in microwave temperature profilers that will give the temperature profile kilometers above and below the aircraft. Upper level highs reside around 200mb at a height of 11,800mb or 11.8km.

The NCAR G-V aircraft can fly above 40,00ft and cover 4,000nm.
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I think the Brady bunch series is in reruns now.
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Quoting RitaEvac:
Russian heatwave is just an isolated event

Wonder if the heat signature there corresponds to the location of the jet stream the last while...
Member Since: October 25, 2005 Posts: 19 Comments: 20742
Quoting Enigma713:

Flood, what have you been feeding everyone on the blog? Where did this love-fest come from?

~Jeffs713


i love flood! he laughs at my corny jokes :)
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Quoting jasoncoolman2010xx:
tom brady will not play in that game,,




Link

The Saints defense abused New England's pass protection in practice. In one-on-one drills, it seemed like the Saints rushers were consistently getting by New England's pass blockers. New England coaches at one point even yelled at their players demanding that they stop holding.

We likely won't see much of Aaron Hernandez in pass protection, as he was abused by Will Smith and gave up a strip sack on Tom Brady in practice.

New England's aerial attack is essential to their success on offense, and Brady is the engine that keeps the Flying Elvises flying.


Lucky for Him Cool Whip Jason
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Quoting Tropicsweatherpr:


Levi, do you have a graphic of the 12z run?


Member Since: November 24, 2005 Posts: 628 Comments: 26460
Quoting Floodman:


Why thank you Pottery...feel like I should be giving an acceptance speech or something

Flood, what have you been feeding everyone on the blog? Where did this love-fest come from?

~Jeffs713
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512. IKE
Quoting Cotillion:


Yeah, the Euro shows it, but I agree, both 500 and 850mb views do not exactly ramp it up the way the GFS wishes to.


That's what I'm getting at...it shows it as a weaker low then the former TD that is near New Orleans.

Maybe it'll show it stronger on the next run.
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I think PsychicMaria good forecast something to develop after the 20th in the Atlantic. These models are amazing I tell ya. What would we do without them.
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Quoting Levi32:
ECMWF shows Cape Verde development now as well.


Levi, do you have a graphic of the 12z run?
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Quoting IKE:


But what it shows is 1012 mb's....at 240 hours....the NHC update that nrtiwlnvragn just posted in post 459 on former TD5 shows a pressure of 1008 mb's, to show a comparison....



Yeah, the Euro shows it, but I agree, both 500 and 850mb views do not exactly ramp it up the way the GFS wishes to.
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A embeded you tube cant bogged the blog.

I suggest a No-ads membership or a good Ad Blocker.
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Is it me or did 480. Drakoen 3:12 PM EDT mess up the blog?
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Floater - Rainbow Color Infrared Loop
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Quoting pottery:

I love you too, Flood.

(it's Floodman appreciation day today)


Why thank you Pottery...feel like I should be giving an acceptance speech or something
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500. IKE
Quoting Jeff9641:


What? I see 2 systems.


See my previous post.
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Seems NOAA has the words on the heating.

Run with dem NOAA Hurricane Numbers,,but go ahead and dismiss the science on the warming.


The Dark Ages come to mind..

Not the "enlightenment"
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498. IKE
Quoting Cotillion:


The 850mb vorticity on the Euro from Raleighwx does, though.


But what it shows is 1012 mb's....at 240 hours....the NHC update that nrtiwlnvragn just posted in post 459 on former TD5 shows a pressure of 1008 mb's, to show a comparison....

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NOAA report,Global warming

About 1,670,000 results (0.28 seconds)
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Quoting RitaEvac:
where its below normal its gotta be above normal to balance itself, thats what makes the world go round!


Original Angular Momentumn makes it go round to be er,,correct.
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if the whole world was average, it would explode!!
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Quoting StSimonsIslandGAGuy:


Considering that the Russian heatwave has killed more than 15,000 people so far, I think the heatwave is considerably more serious than "blah, blah".

And arctic sea ice is well below normal.



Everyone knows that sea ice loss is driven by wind patterns. This year strong clockwise winds have pulled the ice away from the land.



ha!
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where its below normal its gotta be above normal to balance itself, thats what makes the world go round!
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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.