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 Levi32:


Something like 10 runs in a row on the GEFS now. The ensemble means have been pretty incredible for 2 weeks out.


Levi,
GFS seems to be hinting at the idea you were toying with re GOM/remnant TD5 in about 100 hrs etc (some convection dropping into N.GOM). Can you comment on that?
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Quoting FLdewey:
How many eyes does this monsta have?
I can answer that - there are no "i"s in monsta!
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Thank you very much for the explanation Doc. There is no doubt that something strange is happening.
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Quoting Patrap:
On a crude but lighter note today.

Millions Of Barrels Of Oil Safely Reach Port In Major Environmental Catastrophe

PORT FOURCHON, LA—In what may be the greatest environmental disaster in the nation's history, the supertanker TI Oceania docked without incident at the Louisiana Offshore Oil Port Monday and successfully unloaded 3.1 million barrels of dangerous crude oil into the United States.

According to witnesses, the catastrophe began shortly after the tanker, which sailed unimpeded across the Gulf of Mexico, stopped safely at the harbor and made contact with oil company workers on the shore. Soon after, vast amounts of the black, toxic petroleum in the ship's hold were unloaded at an alarming rate into special storage containers on the mainland.

From there, experts confirmed, the oil will likely spread across the entire country's infrastructure and commit unforetold damage to its lakes, streams, and air.

"We're looking at a crisis of cataclysmic proportions," said Charles Hartsell, an environmental scientist at Tufts University. "In a matter of days, this oil may be refined into a lighter substance that, when burned as fuel in vehicles, homes, and businesses, will poison the earth's atmosphere on a terrifying scale."


What is worse is the amount of dihydrogen monoxide being dumped into every part of the environment from multiple sources everyday.
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Afternoon StormW
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Quoting rentyotboy:
Global warming may attribute to fewer Hurricanes?
Never let the facts on the ground interfere with dialogue I guess.


The smart ones have been saying this all along; that there is a possiblity that a warmer atmosphere would produce not only fewer hurricanes, but also increase the intensity of the ones that do form....these theories were based in some part on the supposition the Doc mentions in his blog that a warmer landmass would decrease uplift over the oceans, reducing the number of storms.

Given that the storms are a function of the atmosphere trying to regulate temperature, this could lead some rather incredible storms...
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Wave to watch is the one between 10E and 20E
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176. JRRP
looks like Bill's track
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On a crude but lighter note today.

Millions Of Barrels Of Oil Safely Reach Port In Major Environmental Catastrophe

PORT FOURCHON, LA—In what may be the greatest environmental disaster in the nation's history, the supertanker TI Oceania docked without incident at the Louisiana Offshore Oil Port Monday and successfully unloaded 3.1 million barrels of dangerous crude oil into the United States.

According to witnesses, the catastrophe began shortly after the tanker, which sailed unimpeded across the Gulf of Mexico, stopped safely at the harbor and made contact with oil company workers on the shore. Soon after, vast amounts of the black, toxic petroleum in the ship's hold were unloaded at an alarming rate into special storage containers on the mainland.

From there, experts confirmed, the oil will likely spread across the entire country's infrastructure and commit unforetold damage to its lakes, streams, and air.

"We're looking at a crisis of cataclysmic proportions," said Charles Hartsell, an environmental scientist at Tufts University. "In a matter of days, this oil may be refined into a lighter substance that, when burned as fuel in vehicles, homes, and businesses, will poison the earth's atmosphere on a terrifying scale."
Member Since: July 3, 2005 Posts: 423 Comments: 128217
that was a very good analysis by Dr Masters on the slow atlantic season. now judging from the models again we shhould see a ramp up in activity and see our fisrt long track cape verde cyclone come 20th august.
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Quoting MiamiHurricanes09:
No, but it's a monster!





looks like its forcasting a other one
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Quoting Drakoen:


This reminds me of when the GFS sniffed out Dean almost two weeks in advance.


I was thinking the same thing. The situation is actually pretty realistic given the pattern, so something to watch for.
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Who knows what we might see in our lifetimes?.......Perhaps only one "monster cane" in a season taking out the entire Eastern Seaboard.......Sounds like a movie script..... :)
Member Since: August 8, 2006 Posts: 0 Comments: 9111
Global warming may attribute to fewer Hurricanes?
Never let the facts on the ground interfere with dialogue I guess.
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"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:

Might this then portend a VERY interesting fall part of the hurricane season? As I understand it tropical storms help to cool the sea surface. With such storms suppressed might the already record-warm seas become even warmer? Then, when the land cools in September might "perfect storm" conditions develop?
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Quoting Patrap:
the latest run of the gfs scares the carp out of me

One may need to see a Dr. about that..
Fish arent supposed to do that after digesting


That may be more a function of how it was eaten...LOL
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164. MahFL
Quoting FLdewey:
How is it nola.com doesn't mention anything about this storm? I know it's weak but come on Times Picayune. You open with "Benedictine monks suing Louisiana regulators over casket sales".

Really?

FAIL.


What storm ?
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Quoting Levi32:


Something like 10 runs in a row on the GEFS now. The ensemble means have been pretty incredible for 2 weeks out.


This reminds me of when the GFS sniffed out Dean almost two weeks in advance.
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Quoting DestinJeff:


Probably so.

Here is my concern. If we are to use the working theory of too much heat, then it is pointless to use analog years in determining seasonal forecasts ... since the excess heat variable will be missing from the analogs.

But if there is an analog with execessive heat, then our current theory of a warming climate is kind of questionable ... because why in the world would there have been anogulous excessive heat back in year X?

These circular references confuse me. And Excel.


The question isn't so much excessive heat (though this year that is the case), but steadily and incrementally increasing heat
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For those who missed it:

Shut up, already!
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the latest run of the gfs scares the carp out of me

One may need to see a Dr. about that..
Fish arent supposed to do that after digesting
Member Since: July 3, 2005 Posts: 423 Comments: 128217
Quoting Drakoen:
Impressive and consistent development on the GFS for a Cape Verde storm with support from the GEFS.


Something like 10 runs in a row on the GEFS now. The ensemble means have been pretty incredible for 2 weeks out.
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155. MahFL
Quoting BadHurricane:
In other words, scientists have no idea what was going on. So typical ... Why pay them at all?


So you want all the scientists children to starve slowly to death ?
Member Since: June 9, 2004 Posts: 0 Comments: 3487
what is a GEFS. ???
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Quoting clwstmchasr:



The good news is that it take it out to sea.


The High should take it further West.
Could be a buzzsaw
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151. BDAwx
the latest run of the gfs scares the carp out of me :O so glad its just a model.
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Quoting StormW:
Hey Levi!


Hey Storm, good update this morning.
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149. MahFL
"Computer simulations of a future warmer climate generally show a reduction in global number of tropical cyclones (though the strongest storms get stronger)" ,

That sounds potentially bad for someone....
Member Since: June 9, 2004 Posts: 0 Comments: 3487
Quoting MiamiHurricanes09:
No, but it's a monster!



WOW!
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Impressive and consistent development on the GFS for a Cape Verde storm with support from the GEFS.
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The circulation center seems to be drifting right over Lake Pontchartrain which is 88F currently.



Member Since: July 3, 2005 Posts: 423 Comments: 128217
Quoting Levi32:


Well it's a major on the model but a large one so the pressure will show lower, but ya. Specifics mean little but the Atlantic should be ripe to finally pop a big one in this pattern.
You said it.

Later everyone!
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Quoting JRRP:
cat 7




looks like its heading too FL
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I think part of the problem here is that we generally assume that there is a single outcome of GW or Climate Change. The reality is, as change is happening, there's no certainty in HOW it's changing. There's so many factors, that is why weather is so fascinating to me. In a chemistry experiment, very few unexpected outcomes occur. Troubleshooting and learning about processes is the fun of it all.

Bottomline: Don't jump to conclusions.

A side note, thanks to everyone here, or at least those not on my ignore list. You increase my knowledge and interest and weather every day.
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Quoting NEwxguy:
To me the key word is prediction,thats all these are,they look at all the indications and give their predictions.You can put any label you want,downcasting,upcasting,hypercasting,whatever,but what it is is a prediction.And anyone who has followed the seasonal forecasts knows the success rate,its not very high,why?Because mother nature doesn't follow statistics.
So what can we do,just wait and see what happens,and take heed to the indications that the environment is going to be ripe for developement in soon.


Spot on and well said...
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Quoting Patrap:


The motion has gone NULL the past few hours.



CST.

I was just about to say the same. Shell Beach has had winds basically out of the North for 9 hours and sustained near 20 kts. for 7 hours now. Reorganized xTD5 is going nowhere fast. I've been waiting all morning for the "eye" to reach me in Metairie!
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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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