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 LoneStarWeather:
So a TD, an open wave and a ULL walk into a bar and the ULL says...


..."looks like i'm taking you both home for a spanking..."
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Quoting StormGoddess:

Hey there Ripplin! :)
Howdy Ma'am...
Member Since: July 30, 2010 Posts: 0 Comments: 491
So a TD, an open wave and a ULL walk into a bar and the ULL says...
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Quoting DestinJeff:


Brownsville, TX. Go ahead.

Blogger? Hello, Brownsville, TX.

he is a nightmare though..
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Quoting RipplinH2O:
Howdy all...

Hey there Ripplin! :)
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979. Vero1
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU AUG 12 2010

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 18N32W TO 6N29W MOVING W 10-15 KT.
THE WAVE LOCATION IS BETTER APPARENT IN THE MID LEVELS OF THE
ATMOSPHERE...SUCH AS THE 700 MB STREAMLINE ANALYSIS. SATELLITE
IMAGERY INDICATES WEAK LOW-LEVEL CYCLONIC FLOW IN THE VICINITY
OF THE WAVE AXIS CONFIRMED BY SATELLITE DERIVED WINDS. DUE TO A
LARGE AREA OF DRY SAHARAN AIR AND DUST EAST OF THE WAVE
AXIS...CONVECTION IS CONSTRAINED TO THE ITCZ.

TROPICAL WAVE IS NORTHEAST OF THE LEEWARD ISLANDS FROM 22N58W TO
16N60W MOVING NW 10-15 KT. SATELLITE IMAGERY INDICATES
LOW/MID-LEVEL CYCLONIC TURNING AROUND THE WAVE AXIS.
THE WAVE
ALSO LIES EMBEDDED IN A DEEP LAYER MOISTURE MAXIMUM EVIDENT IN
TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS FROM 16N TO 20N BETWEEN 57W AND 61W...AND
FROM 20N TO 23N BETWEEN 54W AND 57W.

TROPICAL WAVE EXTENDS ACROSS HISPANIOLA FROM 23N70W TO 17N73W
MOVING WNW NEAR 10 KT. TOTAL PRECIPITABLE WATER IMAGERY
INDICATES AN AREA OF ENHANCED MOISTURE ACROSS THE N CENTRAL
CARIBBEAN IN WHICH THE WAVE IS EMBEDDED. WEAK TURNING IS
OBSERVED IN THE VICINITY OF THE WAVE. MOST OF THE SHOWER
ACTIVITY ASSOCIATED WITH THE WAVE IS OVER HISPANIOLA AND WITHIN
90 NM OFF THE SOUTHERN COAST OF THE ISLAND. DOPPLER RADAR
IMAGERY FROM PUERTO RICO ALSO INDICATES SCATTERED SHOWERS ACROSS
THE ISLAND WITH ISOLATED SHOWERS SURROUNDING THE ISLAND FROM 15N
TO 20N WEST OF 63W.

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978. SLU
Goodnight all

I've been very busy today so I haven't been up to date with the lasted happenings. Apparently I haven't missed anything.

Just so add to what Dr. Masters said in his blog earlier. The Northern Hemisphere is off to a record slow start and going back to my post last night, I indicated that we could be in line for a season that conforms to climatology as far as when the main activity occurs. Now when you look at the SSTs profile of the whole world, the warmest anomalies in the tropics exist in the Atlantic. Based on that fact, there's no need to guess where the party will take place in 2010.

Now since the majority of the activity this year could take place in the Atlantic Basin, the main reason why the Northern Hemisphere's storm count is the lowest in recorded history could be because the Atlantic hasn't reached it's climatological peak as yet. When it does shortly, we could easily catch up.

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Quoting RipplinH2O:
The "New's" play tonight and we'll either have the entire NOLA crowd doing the "TWO DAT" for the next month and a half or everyone else taking off the S...


You're going to have to forgive me...I do not follow sports at all...what's the "news"?
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Quoting Krycek1984:
I'm sick of seeing that chart several times a day with a snarky comment attached. It's condescending.

Which chart is that? Oh Jeff, could you help us out and clarify which chart this blogger is talking about?
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Member Since: July 15, 2006 Posts: 169 Comments: 53296
Quoting Krycek1984:
What's all this talk about football...I thought football season doesn't start for a long time?
The "New's" play tonight and we'll either have the entire NOLA crowd doing the "TWO DAT" for the next month and a half or everyone else taking off the S...
Member Since: July 30, 2010 Posts: 0 Comments: 491
969. JLPR2
Hello to everyone in the very quiet blog!
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I'm sick of seeing that chart several times a day with a snarky comment attached. It's condescending.
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967. JLPR2
Quoting DestinJeff:
Wow. What a find! I was cleaning out some drawers and I found an old copy of a chart we used to refer to when discussing average seasonal activity patterns in the Atlantic.



impressive XD
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Quoting Krycek1984:
What's all this talk about football...I thought football season doesn't start for a long time?

Football is always a valid topic regardless of time of year.
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What's all this talk about football...I thought football season doesn't start for a long time?
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963. IKE
Quoting DestinJeff:


should I go ahead and blast you now for using the NOGAPS as support for non-development off of Africa, or would you rather wait for the usual suspects?


Que the Brownsville,TX. blogger.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
TD5 has never left the gulf.. The center is spinning directly below the sate of Mississippi. Check it out on radar out of Gulfport. Plain as day.
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Quoting IKE:
NOGAPS at 18Z @ 144 hours...nothing off of Africa....Link


Speaking of Africa....
yep them there be the ones everyone needs to see
Member Since: July 15, 2006 Posts: 169 Comments: 53296
959. IKE
Quoting KEEPEROFTHEGATE:


silence

we only want to see the models that show nothing from you

lol


C post #956...courtesy of the Navy.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Why aren't the models picking up on that strong 850mb vort max associated with the wave near 10W/15N?
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956. IKE
NOGAPS at 18Z @ 144 hours...nothing off of Africa....Link


Speaking of Africa....
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Now now boys....yall play nice!!

Oh and one more thing, WHO DAT BABY!
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Quoting DestinJeff:


Big Time Rush is on. I know that is where Dewey is.


Yeah, it's on in the background here too!
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Thank goodness finally found the game. Don't like that NE already has 3 though! URGHHHHHH
Member Since: September 7, 2005 Posts: 0 Comments: 274
Quoting IKE:
Combination of A and C.


silence

we only want to see the models that show nothing from you

lol
Member Since: July 15, 2006 Posts: 169 Comments: 53296
951. RipplinH2O
11:48 PM GMT on August 12, 2010
Quoting aquak9:
(ooops)

hi ripplin'. Blog is SO SLOW. I'm worn out from bein' bored.
Dang! So much for the new car...Hi Water Pup, how's the water?
Member Since: July 30, 2010 Posts: 0 Comments: 491
950. aquak9
11:46 PM GMT on August 12, 2010
(ooops)

hi ripplin'. Blog is SO SLOW. I'm worn out from bein' bored.
Member Since: August 13, 2005 Posts: 163 Comments: 25732
949. robj144
11:46 PM GMT on August 12, 2010
Quoting jasoncoolman2010xx:
tom brady will not play in that game,,


Hmm... that looks like Tom Brady on the field right now. Weird...
Member Since: August 19, 2008 Posts: 0 Comments: 825
948. KEEPEROFTHEGATE (Mod)
11:45 PM GMT on August 12, 2010
NMFC Norfolk Tropical Feed
No Active Tropical Warnings in the Atlantic, Caribbean, or Gulf of Mexico


As of Thu 12 Aug 2010 23:30:01Z
Member Since: July 15, 2006 Posts: 169 Comments: 53296
947. stormy3
11:45 PM GMT on August 12, 2010
E) all of the above
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946. RipplinH2O
11:45 PM GMT on August 12, 2010
In case anyone else is counting, that was my 20th new guy "Howdy all" without a response. I'm celebrating with a drink. If I get to 50, I'm buying a new car...
Member Since: July 30, 2010 Posts: 0 Comments: 491
945. IKE
11:45 PM GMT on August 12, 2010
Combination of A and C.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
944. TropicalAnalystwx13
11:44 PM GMT on August 12, 2010
000
ABNT20 KNHC 122343
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT THU AUG 12 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE BROAD AREA OF LOW PRESSURE ASSOCIATED WITH THE REMNANTS OF
TROPICAL DEPRESSION FIVE HAS MOVED LITTLE OVER THE PAST FEW HOURS
AND IS LOCATED NEAR THE COAST OF SOUTHEASTERN LOUISIANA AND
MISSISSIPPI. THE LOW IS EXPECTED TO PRODUCE LOCALLY HEAVY RAINS AND
OCCASIONALLY GUSTY WINDS IN SQUALLS AS IT DRIFTS INLAND DURING THE
NEXT DAY OR SO. THERE IS A LOW CHANCE...NEAR 0 PERCENT...OF THIS
SYSTEM REDEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT 48
HOURS. LOCALIZED FLOODING IS POSSIBLE OVER SOUTHERN LOUISIANA AND
COASTAL MISSISSIPPI...PLEASE REFER TO STATEMENTS FROM LOCAL NATIONAL
WEATHER SERVICE FORECAST OFFICES FOR ADDITIONAL INFORMATION ON THIS
SYSTEM.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
Member Since: July 6, 2010 Posts: 113 Comments: 31446
943. aquak9
11:44 PM GMT on August 12, 2010
D
Member Since: August 13, 2005 Posts: 163 Comments: 25732
942. KEEPEROFTHEGATE (Mod)
11:43 PM GMT on August 12, 2010
time for a little poll
next TWO will show

A)NO CYCLONES AT THIS TIME
B)NO CYCLONES AT THIS TIME
C)NO CYCLONES AT THIS TIME
D)NO TROPICAL CYCLONES NEXT 48 HRS
Member Since: July 15, 2006 Posts: 169 Comments: 53296
941. STXpat
11:42 PM GMT on August 12, 2010
Here's what i think is a cause for less than the hyped expectations,(so far). Oceans are Hot;Atmosphere is Hot.Cyclones need temperature,contrasts?; in order to generate convection.There's plenty of heat,plenty of moisture,but it can't rise to the upper atmosphere,any more than sweat will cool you in houston when it's 100 deg.,and 100% humidity.Lotsa steam,but no action.
Member Since: September 18, 2008 Posts: 0 Comments: 36
940. JRRP
11:39 PM GMT on August 12, 2010
GFS still show a super hyper extra mega hurricane
Member Since: August 16, 2007 Posts: 0 Comments: 5337
938. blsealevel
11:38 PM GMT on August 12, 2010

here ya go shaa; games on
Member Since: August 23, 2008 Posts: 0 Comments: 1918

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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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