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 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!
Quoting MiamiHurricanes09:
No, but it's a monster!



Thank god that's 384 hours out. Lets see if models will jump on with this system. CMC and ECMWF are only hinting at it.
Member Since: July 8, 2005 Posts: 259 Comments: 24186
Quoting StormSurgeon:


Yep, I hear some thunder. Need the rain too, all these T-storms lately have managed to miss me
Tell me about it. I'm by the Island and all I can get is a sprinkle.
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Quoting MiamiHurricanes09:
I've never seen the GFS go so aggressive on a system...I mean this has to be a category 5 what it develops.


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.
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Member Since: July 3, 2005 Posts: 426 Comments: 128668
Thanks Dr. Masters...

Hmm, record warm SST's accompanied by drier than normal air... Is there any possibility that there's enough oil mixed in with the water out there in the Atlantic that evaporation is reduced? I would think we could detect something like that, but reduced evaporative cooling would cause warmer SST's and drier air.
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Quoting MiamiHurricanes09:
No, but it's a monster!



Holy heck.
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I've never seen the GFS go so aggressive on a system...I mean this has to be a category 5 what it develops.
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Quoting Patrap:
Zoomed out to Long Range,,Mobile is going to get a feeder ..and the energy has spread out some since dawn too.



Yep, I hear some thunder. Need the rain too, all these T-storms lately have managed to miss me
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126. JRRP
cat 7
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125. Prgal
Quoting MiamiHurricanes09:
Link.


Thank you very much!
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Quoting Levi32:
12z GFS 252 hours....guess where this is going during the next several days on the model....see the ridge? It's going west. 384 hours will likely show this threatening the US again.

No, but it's a monster!

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Quoting DestinJeff:
If there is a 90% chance of rain on a given day, you rightfully expect some rain.

Now if it is mid afternoon and no rain is in the area, then typically you will say "busted forecast" Usually won't just say, well the 90% chance from today is actually tomorrow or "next week. you'll see."


True. But if the forecast calls for a 90% chance of evening showers, you don't start calling "busted forecast" just because it hasn't started pouring by 3:30 in the afternoon.
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Quoting Levi32:
12z GFS 252 hours....guess where this is going during the next several days on the model....see the ridge? It's going west. 384 hours will likely show this threatening the US again.

The GFS and NAM both picked up on that storm. Preparation and knowledge are key during this time.
Member Since: July 12, 2010 Posts: 0 Comments: 235
Quoting Prgal:


Link please?
Link.
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Quoting RuBRNded:


But you can hang your hat on it.


That's just wrong...funny, yes, but oh so wrong...LOL
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Hi sheri..all the convection is part of the former TD in the GOM..as for the event tonight its after Sunset..




A Perseid meteor photographed in Aug. 2009 by Pete Lawrence of Selsey, UK.

Planets Align for the Perseid Meteor Shower

August 5, 2010: You know it's a good night when a beautiful alignment of planets is the second best thing that's going to happen.

Thursday, August 12th, is such a night.

The show begins at sundown when Venus, Saturn, Mars and the crescent Moon pop out of the western twilight in tight conjunction. All four heavenly objects will fit within a circle about 10 degrees in diameter, beaming together through the dusky colors of sunset. No telescope is required to enjoy this naked-eye event: sky map.
Perseids 2010 (Pete Lawrence, 200px)
A Perseid meteor photographed in Aug. 2009 by Pete Lawrence of Selsey, UK. [more]

The planets will hang together in the western sky until 10 pm or so. When they leave, following the sun below the horizon, you should stay, because that is when the Perseid meteor shower begins. From 10 pm until dawn, meteors will flit across the starry sky in a display that's even more exciting than a planetary get-together.

The Perseid meteor shower is caused by debris from Comet Swift-Tuttle. Every 133 years the huge comet swings through the inner solar system and leaves behind a trail of dust and gravel. When Earth passes through the debris, specks of comet-stuff hit the atmosphere at 140,000 mph and disintegrate in flashes of light. These meteors are called Perseids because they fly out of the constellation Perseus.
Member Since: July 3, 2005 Posts: 426 Comments: 128668
Quoting RMCF:

with your screen name i thought you were on summer break to.


Not sure how my screen name computes to Summer Break in your head but I've been around here for a few years with the same name. Anyone that wishes for a Cat 5 is either a child or not of sound mind, I chose the child route because that's typically less insulting but should get the point across.
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Quoting Patrap:


Was bad at 4-6 am..then it slacked off Rain wise,,but just now beginning again.
Some street flooding occurred at Rush hour in the City in the reg areas and in Metairie as well.



Yeah, TS and TD are not a great deal for the NOLA area; it's par for the course...the last thing anyone wants is a major in SELA
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114. TGTTX
Quoting Patrap:
51. Floodman 11:17 AM CDT on August 12, 2010


I agree with Sgt. Hulka for sho.


I lack the knowledge and experience to forecast anything objectively. Having said that, I do live on the coast (SETX) and have witnessed firsthand the destruction hurricanes can bring, and have experienced the angst over making difficult and important decisions under the pressure of lurking, real danger.

In that light, I find what I perceive to be "the need to be right" equally fascinating and disturbing when expressed in this numbers game. I tend to mostly disregard those folks who want to argue over the numbers and say "I'm right and you're wrong" or "See, I told you so!" The folks I respect the most on here are those who have the humility to avoid that silliness. I understand they are expressing their opinions on risk based upon what they have learned and seen and experienced from their studies, observations and present and historical data. Given that, I really don't care whether they are dead-on or not. I do care that they continue to share with us.

So, thanks to you folks (there really are many -- Dr. M., Storm W, Pat, Drak, Levi, Flood, and more) for sharing your thoughts with us. To me, whether you are always 100% accurate in your predictions is not nearly as important nor as valuable as your willingness to share them with us, along with your reasoning and observations, so we can make our own informed decisions.
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Living here in Puerto Rico, we're right in the bullseye (or at least close to it) and it has been a slow start to the 2010 hurricane season. I expected to see more activity in the GOM/Western Caribbean early on which to me was odd. I was also concerned with the activity off the coast of Africa as I somewhat expected that that area would not start firing off until mid to late August. I was also surprised with the number of tropical waves coming off of Africa. All said, I would think that we are in for an unusual year. Unfortunately here in PR, all it takes is a cat 1 to really mess things up.....
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iVideo: Street flooding Uptown

Posted on August 12, 2010 at 8:12 AM

Street flooding at the intersection of State Street and Claiborne Avenue.
Member Since: July 3, 2005 Posts: 426 Comments: 128668
110. Prgal
Quoting MiamiHurricanes09:
12z GFS 252 hours:



Link please?
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12z GFS 252 hours....guess where this is going during the next several days on the model....see the ridge? It's going west. 384 hours will likely show this threatening the US again.

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Quoting angiest:


I've suggested a warmer climate (regardless of cause) would possibly lead to less tropical cyclones..

But, didn't we hear in 2005 that the hyperactivity was due to global warming?


Some were saying that the intensity was a function of the warming atmosphere, but yes, you're right, there some that said the heightened activity was casued by it
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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.
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Quoting Floodman:


Yeah, man...it's dangerous and it supposedly hurts1


But you can hang your hat on it.
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Quoting vinotinto:
So I guess Al Gore was wrong....again.Quoting Patrap:
NEXRAD Radar
New Orleans, Composite Reflectivity Range 124 NMI






Morning Pat, I was wondering on ur second image what is that other big glob out there is apart of td5? Also do you think here in Alabama we can see the solar thing you posted would love to be able to see it and which way do I look? don't mean to sound stupid just wondering.
sheri
Member Since: August 24, 2006 Posts: 21 Comments: 3678
Quoting Floodman:



How is it at your house, Pat? It was looking like a hit on the Rigolets for a minute there


Was bad at 4-6 am..then it slacked off Rain wise,,but just now beginning again.
Some street flooding occurred at Rush hour in the City in the reg areas and in Metairie as well.

Member Since: July 3, 2005 Posts: 426 Comments: 128668
Atlantic Ocean View (Updated ~3 hours)
Member Since: July 3, 2005 Posts: 426 Comments: 128668
Quoting Patrap:
Zoomed out to Long Range,,Mobile is going to get a feeder ..and the energy has spread out some since dawn too.



How is it at your house, Pat? It was looking like a hit on the Rigolets for a minute there
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12z GFS 252 hours:

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99. JRRP
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Quoting clwstmchasr:
In Dr. Master's blog he indicates that unusually dry atmosphere in the Atlantic is mainly responsible for the lack of instability.

What he does not say is that there are signs of this changing.




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.
Member Since: July 3, 2005 Posts: 426 Comments: 128668
Zoomed out to Long Range,,Mobile is going to get a feeder ..and the energy has spread out some since dawn too.

Member Since: July 3, 2005 Posts: 426 Comments: 128668
Quoting weathermancer:
Red Sky in the Morning
The IR looks boring
lol


Nah, more like

Red sky in the morning
Here comes the gale warning

LOL
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94. JRRP
Quoting MiamiHurricanes09:
12z GFS 144 hours develops the tropical wave currently over Central Africa. It already looks like a tropical depression(on the GFS) and it only was a couple of hours over water.



By 192 hours we are dealing with our first Cape Verde hurricane.



omg a beast
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93. RMCF
Quoting 69Viking:


Proof that school's still out in some areas!

with your screen name i thought you were on summer break to.
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Quoting Floodman:


Yeah, let's go back to "Red sky at morning, sailor take warning, red sky at night sailor's delight"

Do that for a while and tell nme how it works out for you...in the meantime I'll pay attention to the guys who do this for a living...they may be wrong soemtimes but I do tend to get a few days warning before any major changes...LOL


+1 for sure...I was ROTFLMAO on this one Floodman...thanks for making my morning...

v/r

Jon
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Quoting DestinJeff:
So, in fact, this season has been a dud up to this point (especially relative to expectations)

I like this from the entry:

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

I'll go with natural variability.


I've suggested a warmer climate (regardless of cause) would possibly lead to less tropical cyclones..

But, didn't we hear in 2005 that the hyperactivity was due to global warming?
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Quoting KEEPEROFTHEGATE:
iam sticking with my too much heat approach and doc appears to be thinking that way as well and maybe some others we are at the half time getting ready for the start lets finish the game


Personally I think it's not the excess heat but the lack of wind....
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Quoting Patrap:
TD..all I can say..iz

ooofh,,dats a Hotsui


its gonna be a good night to sit in, enjoy a few brews, and watch the game :)

errrr..... at least the first few possessions lol
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Quoting FLdewey:
If you experience natural variability for more than 4 hours please consult a doctor.


Yeah, man...it's dangerous and it supposedly hurts1
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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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