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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Thats for the Synopsis Storm!
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Quoting Drakoen:
ECMWF 00z a little more aggressive on the GOM low:



0z UKMET
96hrs
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Quoting StormW:


???


Storm at this point the GFS has been back and forth showing a pretty substantial trough in the Western atl. Just some long range speculation. I've been on high the past couple days found out after a very long road that wifey is 5 weeks pregnant hope your doing ok.
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Quoting hydrus:
Check out the strength of the low that moves off of Africa in a few days. It looks like a tropical storm before it hits the water.Link


I know. Models are starting to pick up now on Cape Verde development. GFS and the ECMWF, our two most reliable are showing it.
Member Since: July 8, 2005 Posts: 259 Comments: 24476
Thanks StormW. Great synopsis and I will be listeng to you as the season ramps up. I live on the southeast coast in the beautiful "lowcountry" of SC. I remember vividly Hugo from 1989 and am now getting prepared.
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Good Morning all, Is the rain and thunderstorms here in Mobile come from the remnants of TD5? Just was wondering. It looks like on radar a little bity spin, I know it can't do much but at least where getting some rain and some cooler temps.
Sheri
Member Since: August 24, 2006 Posts: 21 Comments: 3683
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Member Since: July 8, 2005 Posts: 259 Comments: 24476
1778. Drakoen
ECMWF 00z a little more aggressive on the GOM low:

Member Since: October 28, 2006 Posts: 57 Comments: 30615
Interesting system drifting ESE toward Bermuda.
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1776. hydrus
Quoting CybrTeddy:
lotta MJO over Africa these days. More rain, more waves.

Check out the strength of the low that moves off of Africa in a few days. It looks like a tropical storm before it hits the water.Link
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The wave in the corner of this image is the wave that the models are developing.

Member Since: July 8, 2005 Posts: 259 Comments: 24476
Pretty favorable pattern in place were it will be pretty diffcult for CV wave to threaten the US.
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lotta MJO over Africa these days. More rain, more waves.

Member Since: July 8, 2005 Posts: 259 Comments: 24476
05L model runs

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1770. hydrus
Quoting BenBIogger:


That is what low MSLP can do to a model.
It does seem to have a thing for Nicaragua.:)
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DJ, I'm sure you'll be reported, after all there needs to be some standard in this well refined community.
A record high minimum temperature was observed yesterday morning
at Houston Intercontinental Airport. This reading tied the record
set for the month of August...and is only one degree shy of the
all-time high minimum temperature record for Houston.



They are projecting heat indexes of over 110 here this weekend.
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1766. hydrus
Quoting DestinJeff:


Posting The Chart is against Community Standards...



I am such a rebel!
Here ya go...Check out NOLA on the GFS, it looks like they get a hurricane directly out of the east...Link
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Quoting weathermanwannabe:
Good Morning. After reading Dr.M's Blog yesterday and some of the discussion, I don't know that anyone, including the Pros, quite know what exactly will happen this year in the Atlantic Basin.....I think that many assumed that record heat in May/June/July would automatically translate into a flurry of activity in the E-Pac, then shifting into the Atlantic, but it has not happend as of yet and lots of potential "unknowns" out there at the moment. The heat content is certainly still there and the next 6 weeks are the most active historically so I would certainly expect a cluster of storms coming sometime in September but you never know.


I think you have to be careful not to confuse scientific synopsis and climatology with what I would call absolute God like omniscience.

These Mets are really well trained and carry a list of creditials but they are making synopsis based on scientific data- facts...most of the time they are very close if not spot accurate. Sometimes they miss a little. All in all, they are trained and they are commited to helping us understand.

Lets not forget that they also have families, bills, other personal issues so they clock in and out just like us with simular pressures, yet the are commited to being a professional in their field.
Member Since: July 12, 2010 Posts: 0 Comments: 235
Quoting hurricane23:
Models certainly hinting at central/eastern tropical atl development in the coming days. Looks like a weakness is progged around 60-70w were it may have a shot at turning out to sea.


It might, but it is 10 days out or so. You never know.
Member Since: July 8, 2005 Posts: 259 Comments: 24476
Quoting hydrus:
And of course the NOGAPS model has a tropical cyclone striking Nicaragua for the eleventh time...Link


That is what low MSLP can do to a model.
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Models certainly hinting at central/eastern tropical atl development in the coming days. Looks like a weakness is progged around 60-70w were it may have a shot at turning out to sea.
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Quoting BahaHurican:
Sorry for the delay, folks. I had a matter to deal with that took longer than expected...

If you want to participate in the poll, you can go to my blog and post your response. I'm going to be in and out today, so it'll be a lot easier for me to collate all the responses that way. I put guidelines below, and I've repeated them in my blog post. I'd be grateful if someone would cut and paste this to the new blog, which will likely come out while I'm in a meeting this a.m.

--------------------------------

Legends of the Wunderground nominees in cronological order

1. Katrina 2005 "StormTop said it would hit NOLA"
2. Rita 2005 "I tried to evacuate"
3. Wilma 2005 "the definitive pinhole eye"
4. Chris 2006 "Sheared again%u2026 Naturally"
5. Ernesto 2006 "yes it is; no it's not"
6. Dean 2007 "is that cat 5 landfall????"
7. Felix 2007 "graupel in the guts"
8. Humberto 2007? "Talk about explosive cyclogenesis"
9. Karen 2007 "never say die"
10. Dolly 2008 "no closed low"
11. Fay 2008 "Florida vacation"
12. Gustav 2008 "I can fake u out"
13. Ike 2008 aka "Ike Jr."; "Beeline for South Florida! ... NOT"
14. Portlight 2008 formation "We are the Blog"
15. Marco 2008 "World's Smallest 'cane or Largest Tornado"

Now we are ready to vote on the top five legends of the blog. The main requirement is that each event has to have entered the "history" or collective memory of the blog as a notable event. This is beyond simply the fact that a storm was notable for breaking a record or causing a lot of damage.

List your top FIVE picks in order from most legendary to least. If you wish, you can add a comment that explains why you feel your top pick is the most legendary blog event.

The poll will close at midnight EDT [0400 UTC] and I will post results tomorrow morning.

Have fun!






1. Katrina 2005
2. Wilma 2005
3. Portlight 2008
4. Fay 2008 (aka The Joker)
5. Ernesto 2006
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Quoting gordydunnot:
All is quiet in the tropical Atlantic except there is enough dust coming off Africa to choke a horse. Good day everyone.


90% of the Atlantic is dust free
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1758. FLdewey
Community Standards? Don't they make toilets?
Member Since: August 19, 2008 Posts: 42 Comments: 6269
1757. hydrus
Quoting DestinJeff:


Posting The Chart is against Community Standards...



I am such a rebel!
And of course the NOGAPS model has a tropical cyclone striking Nicaragua for the eleventh time...Link
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Quoting DestinJeff:


Posting The Chart is against Community Standards...



I am such a rebel!

You rock, DJ!!
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Quoting gordydunnot:
All is quiet in the tropical Atlantic except there is enough dust coming off Africa to choke a horse. Good day everyone.


Yes, but only if that horse is above 20 latitude
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All is quiet in the tropical Atlantic except there is enough dust coming off Africa to choke a horse. Good day everyone.
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HPC Preliminary Extended Forecast Discussion

Excerpt:

PATTERN CHANGE UNDERWAY WILL PRODUCE WETTER THAN AVERAGE
CONDITIONS ACROSS MUCH OF CONUS FROM THE OH VALLEY TO THE SRN AND
CENTRAL PLAINS AND EWD TO THE EAST COAST. MONSOONAL ACTIVITY WILL
CONTINUE OVER THE MEXICAN SIERRA AND THE SOUTHWEST. THE GULF COAST
REGION FROM LA TO FLORIDA IS LIKELY TO SEE A PROLONGED DAILY
THREAT OF HVY CONVECTION FROM THEH MID LEVEL REMAINS OF A FORMER
TROPICAL DEPRESSION AND SFC LOW DEVELOPMENT IN THIS REGION.

ELSEWHERE STANDARDIZED VELOCITY POTENTIAL ANOMALIES ARE SHOWING
INCREASINGLY FAVORABLE CONDITIONS FOR TROPICAL DEVELOPMENT
BEGINNING LATE IN THE PERIOD OVER THE ERN TROPICAL ATLANTIC.
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Howdy all...GREAT second half last night
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1750. hydrus
Quoting DestinJeff:


The tropics are about to implode!
Interesting feature on the GEM down in the S.W.Caribbean. A few of the models have been picking up on it......Link Maybe more toward the Central Caribbean.
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Good Morning. After reading Dr.M's Blog yesterday and some of the discussion, I don't know that anyone, including the Pros, quite know what exactly will happen this year in the Atlantic Basin.....I think that many assumed that record heat in May/June/July would automatically translate into a flurry of activity in the E-Pac, then shifting into the Atlantic, but it has not happend as of yet and lots of potential "unknowns" out there at the moment. The heat content is certainly still there and the next 6 weeks are the most active historically so I would certainly expect a cluster of storms coming sometime in September but you never know.
Member Since: Posts: Comments:
Quoting LoneStarWeather:

I just wish there were some chart or graph that could help me understand just when that might happen...


You and me both lonestar.
Member Since: Posts: Comments:
Sorry for the delay, folks. I had a matter to deal with that took longer than expected...

If you want to participate in the poll, you can go to my blog and post your response. I'm going to be in and out today, so it'll be a lot easier for me to collate all the responses that way. I put guidelines below, and I've repeated them in my blog post. I'd be grateful if someone would cut and paste this to the new blog, which will likely come out while I'm in a meeting this a.m.

--------------------------------

Legends of the Wunderground nominees in cronological order

1. Katrina 2005 "StormTop said it would hit NOLA"
2. Rita 2005 "I tried to evacuate"
3. Wilma 2005 "the definitive pinhole eye"
4. Chris 2006 "Sheared again%u2026 Naturally"
5. Ernesto 2006 "yes it is; no it's not"
6. Dean 2007 "is that cat 5 landfall????"
7. Felix 2007 "graupel in the guts"
8. Humberto 2007? "Talk about explosive cyclogenesis"
9. Karen 2007 "never say die"
10. Dolly 2008 "no closed low"
11. Fay 2008 "Florida vacation"
12. Gustav 2008 "I can fake u out"
13. Ike 2008 aka "Ike Jr."; "Beeline for South Florida! ... NOT"
14. Portlight 2008 formation "We are the Blog"
15. Marco 2008 "World's Smallest 'cane or Largest Tornado"

Now we are ready to vote on the top five legends of the blog. The main requirement is that each event has to have entered the "history" or collective memory of the blog as a notable event. This is beyond simply the fact that a storm was notable for breaking a record or causing a lot of damage.

List your top FIVE picks in order from most legendary to least. If you wish, you can add a comment that explains why you feel your top pick is the most legendary blog event.

The poll will close at midnight EDT [0400 UTC] and I will post results tomorrow morning.

Have fun!




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Quoting DestinJeff:


The tropics are about to implode!

I just wish there were some chart or graph that could help me understand just when that might happen...
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Quoting IKE:
MJO charts...updated today....




and.....





Trust the 15 day but not the 40.
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1743. IKE
MJO charts...updated today....




and.....



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1742. hydrus
Quoting mrsalagranny:
I remember Fredrick in 1979 when it pulled the water from Mobile Bay.
I saw footage of Frederick burying a huge piece of plywood into a Buick. It is a good thing nobody was in it, they never would have made it. It was ugly.
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1741. Thaale
Quoting StormW:
EXPLANATION OF THE RELATION OF THE NAO and STORM RECURVATURE

Thanks again for the article, StormW. I just posted a comment with an implicit question in it about your post on your blog, as after I had initially your post the opther day I heard Jeff Masters answer a question about the NAO and steering on his radio show and his answer was somewhat different.
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Good morning tropic buddies! Hope all is well with everyone. Just got done serving breakfast to some very needy people here in Haiti. Breaks my heart at times. Some people just don't know how good they got it until you see hungry women and children pleading for more. Hope the storms stay away from here. That's the last thing these people need.
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Has it been SIX years already since Charley made landfall? Unbelievable... I can still remember sitting in the EOC waiting for the hit here in Clearwater.

Here's a video we did in our office about the storm's aftermath...



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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.