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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By looking at the ensemble variance one can see the different locations where the GEFS wants to put the hurricane in 16 days. The choices picked by the model are either a run at the SE US coast, a slow, late recurve, or a rapid and early recurve.

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Damage coming in well to the north of Washington D.C.



08/12/2010 0622 am

4 miles SW of Green Valley, Frederick County.

Thunderstorm wind damage, reported by trained spotter.


Numerous trees down and wires down

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Quoting psuweathernewbie:


Storm it is too bad this wave is moving out to sea, given that it has a tremendous low level circulation which is stronger than the second wave.


please explain to me just why it is so bad that it is going out to sea?
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633. xcool


xcool
Member Since: September 26, 2009 Posts: 2 Comments: 15670
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
427 PM EDT THU AUG 12 2010

MDC013-021-122100-
/O.CON.KLWX.TO.W.0015.000000T0000Z-100812T2100Z/
CARROLL MD-FREDERICK MD-
427 PM EDT THU AUG 12 2010

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 500 PM EDT FOR
NORTHEASTERN FREDERICK AND NORTHWESTERN CARROLL COUNTIES...

AT 425 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
STRONGLY INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR
TANEYTOWN... OR 5 MILES SOUTHEAST OF EMMITSBURG...MOVING SOUTHEAST
AT 20 MPH.

LOCATIONS IMPACTED INCLUDE...
KEYMAR...
TANEYTOWN...
LADIESBURG...
NEW MIDWAY...
MIDDLEBURG...
UNION BRIDGE...
LINWOOD...
UNIONTOWN...
WAGNERS MILL...

TAKE COVER NOW! MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING AND AVOID WINDOWS. IF OUTDOORS OR IN A MOBILE HOME OR
VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.
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Quoting hcubed:


With all his different handles, couldn't that "un-named individual" qualify as a group?

He already suffers from "multiple personality disorder".

is it multiple personality disorder when they all act the same with different names?
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Quoting SQUAWK:


Would you believe just South of DC?




The one north of Washington D.C is showing stronger rotation. Plus its just north-west of Baltimore, very populated area compared to warnings to the south. The one to the south needs to be watched too tho.


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Quoting psuweathernewbie:


Storm it is too bad this wave is moving out to sea, given that it has a tremendous low level circulation which is stronger than the second wave.
like the spin you saw west of tampa?
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Quoting hcubed:


With all his different handles, couldn't that "un-named individual" qualify as a group?

He already suffers from "multiple personality disorder".


Most definitely...a largish group (some 17 or so strong) with a terrifyingly similar method of communication and an attitude that says:
"If nothing else works, a total pig-headed unwillingness to look facts in the face will see us through"...no wait, that's someone else...
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SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
432 PM EDT THU AUG 12 2010

VAC099-177-179-630-122042-
/O.CAN.KLWX.TO.W.0014.000000T0000Z-100812T2045Z/
CITY OF FREDERICKSBURG VA-SPOTSYLVANIA VA-KING GEORGE VA-STAFFORD VA-
432 PM EDT THU AUG 12 2010

...THE TORNADO WARNING IS CANCELLED FOR THE CITY OF FREDERICKSBURG...
AND SOUTHEASTERN STAFFORD...KING GEORGE AND EAST CENTRAL SPOTSYLVANIA
COUNTIES...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS EXITED THE WARNED
AREA. THUS THE TORNADO WARNING HAS BEEN CANCELLED.
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Quoting StormW:


The one behind it:

EUMETSAT
img src="


Storm it is too bad this wave is moving out to sea, given that it has a tremendous low level circulation which is stronger than the second wave.
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Quoting Neapolitan:


Thanks for the request, but several forum members seem to be deficient in their ability to read the calendar, so I'll continue to post the "You Are Here" version of that image from time to time for their benefit. If you don't like it, simply press the 'HIDE' button, as I do with many of the multiple illiterate and senseless comments I read here.


Posting it is a good reminder always as memories here run very short for some
Member Since: July 3, 2005 Posts: 424 Comments: 128273
Quoting Floodman:


...I tend to have issues with individuals and not groups (though I could name a few groups that are working their way on to my list)...


With all his different handles, couldn't that "un-named individual" qualify as a group?

He already suffers from "multiple personality disorder".
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Quoting Tazmanian:




we dont need too keep seeing it plzs


Thanks for the request, but several forum members seem to be deficient in their ability to read the calendar, so I'll continue to post the "You Are Here" version of that image from time to time for their benefit. If you don't like it, simply press the 'HIDE' button, as I do with many of the multiple illiterate and senseless comments I read here.
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Quoting Walshy:
Tornado Warnings just north of Washington D.C.


Would you believe just South of DC?

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
417 PM EDT THU AUG 12 2010

VAC099-177-179-630-122045-
/O.CON.KLWX.TO.W.0014.000000T0000Z-100812T2045Z/
CITY OF FREDERICKSBURG VA-SPOTSYLVANIA VA-KING GEORGE VA-STAFFORD VA-
417 PM EDT THU AUG 12 2010

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM EDT FOR THE CITY
OF FREDERICKSBURG...AND SOUTHEASTERN STAFFORD...KING GEORGE AND EAST
CENTRAL SPOTSYLVANIA COUNTIES...

AT 415 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS
TORNADO WAS LOCATED 7 MILES SOUTHWEST OF POTOMAC CREEK...MOVING
SOUTHEAST AT 15 MPH.

LOCATIONS IMPACTED INCLUDE...
SEALSTON...
FAIRVIEW BEACH...
LAMBS CREEK...
DOGUE...
KING GEORGE...
JERSEY...
WEEDONVILLE...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING AND AVOID WINDOWS. IF OUTDOORS OR IN A MOBILE HOME OR
VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.
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Tornado Warnings just north of Washington D.C.
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Quoting DestinJeff:


Don't forget the 12Z IKE Model shows little to nothing through Aug 21.


lol
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Quoting psuweathernewbie:
StormW, that is a huge wave with a large low level circulation reaching from 20N to 10N and from 5W to 10W.


I think this was the wave that may have to be watched in the long range forecast that Storm was alluding to in his blog today.

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610. Prgal
Quoting palmasdelrio:


Can you tell me where you got this map?


Sure! I got it from this page but one of the fellow bloggers pointed out that it was an old image. Link
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609. xcool
THURSDAY 1 PM


Dissipated????


Here is the definition of dissipate...

1. To vanish by dispersion: The dark clouds finally dissipated.


The tropical depression dissipated. Doesn't look that way to me.


In any case, enough of that. The Big Dog today looks at this system and what is going on. The Long Ranger shows why the hurricane season is about to start, and actually I make the case for why the next place to look for development is off the southern Atlantic coast. The European has it. A Midwest trough split, and we open up the area off the southern Atlantic coast. This is the rabbit being pulled out of the hat idea I have reviewed with you. The trough moving off the East Coast now leaves a front off the Southeast coast. In the meantime, the trough that comes into the Plains forces big height rises over the Atlantic northeast of where the surface trough is laying off the southern Atlantic coast. The next front stalls farther north, and then the trough splits over the nation's mid section, with major ridging ballooning northeast out of the Rockies for the Great Lakes and hooking over the top with the Atlantic ridge. Anything off the southern Atlantic coast is then forced up the coast.

Ever wonder why there are big rains in the Northeast when storms are brewing off the southern Atlantic coast? Because you get some kind of front close by. Doria, 1967, Belle, 1976, Gloria, all shared that aspect. But it's the pattern, just like the pattern said to watch the Gulf this week, and we had two, and next week it's off the southern Atlantic coast.

Now once to that, it's look out, the Atlantic wave train starts up. In fact, the GFS has the first of its parade is on it now, though on this run it re-curves, and of course we all know how that model loves to do that. How many times 10-15 days before a storm it has it going to New Orleans on one run, then Newfoundland the next? But the point is looking at the height rise center developing over the top, and you set off the classic pattern at the time of the year when the season ramps up. Remember in 2008, once to Sept. 5, it shut down completely till the 25th. This year when it starts, it will keep going. I showed my clients the similarities to what is setting up with the year of the Florida hurricane, 2004 (strange how we had an El Nino then... I thought that was supposed to shut everything down. The broad brushers love to explain the tropics with one or two spin points, when it's so much more than that).

By the way, the top gusts so far have been near 30 knots at Shell Beach. La., and Southwest Pass. I am not going to score this... unless I see something gusting over 35 knots. I just want to make sure, though, that you understand my consternation with the term "dissipate." You may downgrade it, fine, but this is more organized than it has been for the past couple of days, and certainly has not dissipated... 10 inches of rain on Louisiana coastal waters is not from a dissipated system.

And I see the feared excessive rain corridor is setting up over the East. The upper disturbance is spinning southeast just to the east of me and unloading on my house now... which is making me mad since it means that the grass is going to start growing again, and my of late 220-yard drives (with roll) on the golf course out here will be back down to less than 200 yards.

Ciao for now.


by joe b
Member Since: September 26, 2009 Posts: 2 Comments: 15670
StormW, that is a huge wave with a large low level circulation reaching from 20N to 10N and from 5W to 10W.
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Quoting clwstmchasr:
I post this again for this evening's astute shoppers:

I think we have see that chart about a thousand times now.




we dont need too keep seeing it plzs
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Quoting clwstmchasr:
I post this again for this evening's astute shoppers:

I think we have see that chart about a thousand times now.


Not that version of it you haven't. This is only the third one, so your estimate is roughly 997 too high. ;-)
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Quoting RitaEvac:
it starts at post 480

Mine was jacked up for a bit, but it is OK now. It is only jacked up if you are on the page with post# 480. (so its either 480 or 479 that messed it up)
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Quoting Prgal:
Is this suggesting that there will be two systems one right after the other?



Can you tell me where you got this map?
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Quoting psuweathernewbie:


See the SAL outbreak cloud in the Top right corner of the image? Amazing.
Theres a big wave that will clean everything up for the monster behind.
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Tornado Warning north-west of Baltimore too.

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Quoting pottery:

Hey Baha.
Just had a Compatriot of yours here.
K. Scott? 25-ish.
I know quite a few Scotts. A couple of them school down that way. Or was there on business?
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Latest SAL Atlantic,Re-Loaded
Member Since: July 3, 2005 Posts: 424 Comments: 128273
I post this again for this evening's astute shoppers:

Shut up, already!

bust-cast-ing: (BUST-kasst-ing or BUST-kass-ting) verb 1 : the act of downplaying the eventuality of some future event or condition based solely on one's negative thoughts and/or hopes rather than the study and analysis of available pertinent data 2 : spec. meteorology: the act of ignoring in whole or in part any logical, climatological, and computational data that contradicts one's thoughts and/or hopes when forecasting that a particular weather event will not occur, while putting full faith in only those data which correlate with and support those same negative thoughts and/or hopes.
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Quoting NASA101:


Ya okay! But how many in similar positions went out to sea?! All i am saying that yes it's possible but from what I have seen in the past a storm strengthening into hurricane around 15N-45W needs a very strong high pressure to keep it going WestNW/W
Yeah, I did say MOST others. The landfalling storms, I have to agree with you, were very likely under the influence of a strong SW extending ridge.
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See the SAL outbreak cloud in the Top right corner of the image? Amazing.
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589. Prgal
Quoting nrtiwlnvragn:


So did I, it should go "current" when PREDICT officially starts on Aug 15. He does have another page that seems up to date Link


Thanks!
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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.