CSU: expect a quiet 2012 Atlantic hurricane season; EF-3 tornado confirmed in Texas

By: Dr. Jeff Masters , 2:47 PM GMT on April 05, 2012

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Expect one of the quietest Atlantic hurricane seasons since 1995 this year, say the hurricane forecasting team of Dr. Phil Klotzbach and Dr. Bill Gray of Colorado State University (CSU) in their latest seasonal forecast issued April 4. They call for an Atlantic hurricane season with below-average activity: 10 named storms, 4 hurricanes, and 2 intense hurricanes. An average season has 10 - 11 named storms, 6 hurricanes, and 2 intense hurricanes. The 2012 forecast calls for a below-average chance of a major hurricane hitting the U.S., both along the East Coast (24% chance, 31% chance is average) and the Gulf Coast (24% chance, 30% chance is average). The Caribbean is forecast to have a 34% chance of seeing at least one major hurricane (42% is average.) Four years with similar pre-season March atmospheric and oceanic conditions were selected as "analogue" years that the 2012 hurricane season may resemble: 2009, 2001, 1965, and 1957. These years all had neutral to El Niño conditions during hurricane season. The average activity for these years was 9.5 named storms, 4.8 hurricanes, and 2.3 major hurricanes.


Figure 1. Departure of sea surface temperature (SST) from average for April 5, 2012, as computed by NOAA's NESDIS branch. SSTs in the hurricane Main Development Region (red box) were near average to below-average.

Why the forecast of a quiet season?
The CSU team cited two main reasons why this may be a quieter than average hurricane season:

1) La Niña has weakened rapidly over the tropical Eastern Pacific over the past month, and is expected to be gone by the end of April. In its wake, El Niño conditions may develop in time for the August - September - October peak of hurricane season. If El Niño conditions are present this fall, this will likely bring about a quiet Atlantic hurricane season due to increased upper-level winds over the tropical Atlantic creating wind shear that will tend to tear storms apart. The CSU team is leaning towards putting their trust in the ECMWF model, which is predicting that a weak El Niño event will be in place by fall.

2) Sea surface temperatures (SSTs) in the Main Development Region (MDR) for hurricanes from the Caribbean to the coast of Africa between 10°N and 20°N were near average to below average in March 2012. Virtually all African waves originate in the MDR, and these African waves account for 85% of all Atlantic major hurricanes and 60% of all named storms. When SSTs in the MDR are much above average during hurricane season, a very active season typically results (if there is no El Niño event present.) Conversely, when MDR SSTs are cooler than average, a below-average Atlantic hurricane season is more likely. This year's SSTs in the MDR are among the coolest we've seen since our current active hurricane period began in 1995. The cool temperatures are largely due to strong surface winds that blew during the winter over the tropical Atlantic in response to the positive phase of the North Atlantic Oscillation (NAO.) The strong winds stirred up the water, bringing up cooler waters from the depths.

How good are the April forecasts?
The forecasters are using a new statistical model developed last year for making April forecasts, so we don't have a long enough track record to judge how good the new model is. The new model correctly predicted a more active than average season for last year, though called for more activity than was actually observed. However, April forecasts of hurricane season activity are low-skill, since they must deal with the so-called "predictability barrier." April is the time of year when the El Niño/La Niña phenomenon commonly undergoes a rapid change from one state to another, making it difficult to predict whether we will have El Niño, La Niña, or neutral conditions in place for the coming hurricane season. Correctly predicting this is key, since if El Niño, conditions are present this fall, this will likely bring about a quiet Atlantic hurricane season due to increased upper-level winds over the tropical Atlantic creating wind shear that will tend to tear storms apart.

CSU maintains an Excel spreadsheet of their forecast errors ( expressed as a mathematical correlation coefficient, where positive means a skilled forecast, and negative means they did worse than climatology) for their their April forecasts. For now, these April forecasts should simply be viewed as an interesting research effort that has the potential to make skillful forecasts. The next CSU forecast, due by June 1, is the one worth paying attention to. Their early June forecasts have shown considerable skill over the years.

Preliminary NWS survey of the April 3rd, 2012 Dallas, Texas tornadoes
The Fort Worth Weather Service office began surveying tornado damage yesterday from three tornadoes that ripped through the Dallas metro area on Tuesday afternoon. Official storm surveys will be released in the next few days. The Arlington/Kennendale tornado has a preliminary rating of EF-2. They suspect wind speeds peaked around 135mph, a path length of 4.6 miles, and a maximum width of 400 yards (1/4 mile). The Lancaster/Hutchins tornado has a preliminary rating of EF-2, and they suspect it had a maximum width of 200 yards (1/8 mile). The Forney tornado has a preliminary rating of EF-3, with suspected winds up to 150 mph. Surveys are ongoing--there's a lot of damage to see along the tornado paths. These ratings reflect the most severe damage the teams have seen so far. Eighteen tornado warnings were issued by the National Weather Service in Fort Worth on Tuesday, which saved hundreds of lives. There were no fatalities Tuesday, which is welcome news in the wake of 2011's deadly tornado season.


Figure 2. This photo was taken by a NWS Storm Survey team in Lancaster TX on April 4, 2012. It shows EF-2 tornado damage that occurred in parts of Lancaster on April 3, 2012.


Figure 3. From the Weather Service: This is an aerial photograph of a tornado damaged area in Arlington TX. The damage from the tornado that affected Kennedale and Arlington on April 3, 2012 has been given a preliminary rating of EF-2. The photo was taken on Wednesday, April 4, looking to the east.

Portlight disaster relief charity responds to this year's tornadoes
Disaster relief charity portlight.org sent Thomas Hudson to the DFW area yesterday to do damage assessment and determine whether there is a need for Portlight's services in the wake of the tornadoes. Check out the Portlight blog to see the latest updates, and catch up the great work they've been doing in Harrisburg, Illinois in the wake of the devastating EF-4 tornado that hit the town on Leap Day, 2012.

Jeff Masters

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Since it's really quiet right now
Let's have an APPROPRIATE
Weather Related Meme Contest!!


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Quoting washingtonian115:
I'm tlking about post 554.They need to modify the lat part of the comment.

Oh, lol.
Member Since: July 6, 2010 Posts: 113 Comments: 32811
Quoting TropicalAnalystwx13:

Huh?
I'm talking about post 554.They need to modify the last part of the comment.
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Quoting TropicalAnalystwx13:
12Z ECMWF at 240 hours.




My god...
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Quoting washingtonian115:
Does I'm correct??

Huh?
Member Since: July 6, 2010 Posts: 113 Comments: 32811
Does I'm correct??
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There was a tornado report in Nebraska about one hour ago when an oil rail car was turned over, but I believe it was actually straight-line wind damage from that squall line I briefly mentioned a few hours ago.

2305 ALLIANCE BOX BUTTE NE 4210 10287 ONE RAIL CAR TURNED OVER AT THE RAILYARD ON THE SOUTH SIDE OF ALLIANCE FROM POSSIBLE TORNADO. (CYS)
Member Since: July 6, 2010 Posts: 113 Comments: 32811
Quoting PensacolaDoug:




THE SKY IS FALLING! THE SKY IS FALLING!


I'm not being chicken little.

I hang around science and global warming forums all day long and read all the latest projections and trends.

Even with linear melt rates for ice caps continuing from present rate of melting, you'd get 27.3cm of mean sea level rise in the next 88 years, which is about 11 inches...

Greenland's rate of net annual melting has been doubling about every five years for the past 10 or 15 years.

Comprehend?

With just 1 more doubling in the next five years, and then remaining linear, that would give you about 21 inches of rise by 2100.

With two more doubling within the next 10 years or so, and then becoming linear thereafter, that would give over 40 inches of rise by 2100.

With a couple more doublings...

At least another one or two doubling from today's melt rate of Greenland are easily possible within the next decade or two, and I do mean very, very easily possible.


It's not a joke.

A sea wall or levee cannot stop permanent sea level rise.

Sea walls and levees are intended to stop temporary floods caused by storm surge, rainfall, or wave action, not a permanent, sustained water level rise.
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Quoting TropicalAnalystwx13:

Something is wrong with your battery, I thought your battery would have been fully charged after you sleep
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Quoting tropicfreak:


Development closer to home, so maybe not so much development close to Cape Verde islands, like what we saw with TS Harvey last season, we probably won't see any development from the tropical systems coming off Africa until they are in the Caribbean.
but in el Niño years Central America is rarely hit with tropical cyclones does I am correct?
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Quoting TropicalAnalystwx13:
Tropical Cyclone Heat Potential was not high at all when Hurricane Dean was passing through in the western Caribbean. At least, not compared to recent years at the same time.

2007:



Then again, this was the Tropical Cyclone Heat Potential for Category 5 Hurricane Wilma:



Imagine what would have happened if a hurricane would have passed over this in 2010:



And this is how the Caribbean looks at this time. Let's see how will it be when September arrives.

Member Since: April 29, 2009 Posts: 75 Comments: 14890
Quoting NCHurricane2009:


I think because the Caribbean has the highest heat content in the Atlantic basin.
That could be another reason.Like how Gustav bombed out in the northweast carribean as well.
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12Z ECMWF at 240 hours.


Member Since: July 6, 2010 Posts: 113 Comments: 32811
Quoting TropicalAnalystwx13:
Tropical Cyclone Heat Potential was not high at all when Hurricane Dean was passing through in the western Caribbean. At least, not compared to recent years at the same time.

2007:



Then again, this was the Tropical Cyclone Heat Potential for Category 5 Hurricane Wilma:



Imagine what would have happened if a hurricane would have passed over this in 2020:


You are reading my mind...I was just going to post the same thing. The TCHP in 2007 was still high enough to support quite a few Major hurricanes
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Been waiting for this....thunderstorms getting better organized SE of North Carolina tonight...

http://www.goes.noaa.gov/browsh.html

This system has mainly been a cut-off upper low vortex I've been tracking for days since I first saw it over SW Texas. The same system produced the strong T-storms over the Gulf and SW Florida (I am not sure if it had anything to do with the Dallas tornadoes). I've watched the upper low merge with a persistent northwest Atlantic upper trough today...which probably means subtropcal development is less likely down the road.

The organzing system SE of NC tonight is a surface frontal boundary low supported by the upper low as it merged with the northwest Atlantic upper trough. I think someone posted a model run of a possible subtropical storm by April 9 last week...so that's why I've been watching this system. But unless the northwest Atlantic upper trough amplifies into a cut-off upper low, nothing interesting is going to happen beyond this...
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Quoting allancalderini:
But they are always exceptions Like hurricane Omar of 2008 btw anyone in here knows why tropical depression 16 never strength to a tropical storm?

Land interaction.
Member Since: July 6, 2010 Posts: 113 Comments: 32811
Quoting RTSplayer:


Don't forget Felix and Dean.

Plus Camille also went through the same area, but obviously hooked much harder northwards.

edit:

Camille formed in that area, but didn't really "power up" until in the Gulf, so maybe not the best example.


there is an atmospheric reason for this, which is ironically related to the John Hope rule.

The air moving over Mexico and Central America is forced upward, producing extra lift in the western Caribbean. However, it sinks in the eastern Caribbean, producing the "John Hope Rule" effect. Thus cyclone formation is greatly hindered in the Eastern Caribbean, but enhanced in the Western Caribbean, because of the "lift" produced by the...land mass...ironically...
But they are always exceptions Like hurricane Omar of 2008 btw anyone in here knows why tropical depression 16 never strength to a tropical storm?
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Quoting RTSplayer:


it doesn't matter.

Ok fine, worry about a slightly stronger hurricane, or one in a weird location a decade or two from now...

BS.

In the greater scheme of things, that's not even what global warming is about.

In my little nephew's natural lifetime, the Gulf of Mexico is going to rise so much that it could potentially swallow as much as half of the land south of Highway 190 if the 10 to 11ft of sea level rise prediction comes true.

Even if the more conservative 18 to 36 inches of sea level rise were to happen, that would be devastating for many areas.


A slightly stronger hurricane almost doesn't even matter, since the mean global effects will be so devastating in their own right. In fact, the mean global sea rise and temperature rise will easily do more damage than probably thousands of years worth of "weather".




THE SKY IS FALLING! THE SKY IS FALLING!
Member Since: Posts: Comments:
Tropical Cyclone Heat Potential was not high at all when Hurricane Dean was passing through in the western Caribbean. At least, not compared to recent years at the same time.

2007:



Then again, this was the Tropical Cyclone Heat Potential for Category 5 Hurricane Wilma:



Imagine what would have happened if a hurricane would have passed over this in 2010:

Member Since: July 6, 2010 Posts: 113 Comments: 32811
Quoting TropicalAnalystwx13:
Gilbert looks almost like Wilma, doesn't it?

Amazing storm!!!! this storm was more amazing than Wilma or other recent storms.
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Member Since: July 6, 2010 Posts: 113 Comments: 32811
Quoting TropicalAnalystwx13:
Gilbert looks almost like Wilma, doesn't it?

Amazing storm!!!for me this storm was more amazing than Wilma.
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Quoting RTSplayer:


Don't forget Felix and Dean.

Plus Camille also went through the same area, but obviously hooked much harder northwards.

edit:

Camille formed in that area, but didn't really "power up" until in the Gulf, so maybe not the best example.


there is an atmospheric reason for this, which is ironically related to the John Hope rule.

The air moving over Mexico and Central America is forced upward, producing extra lift in the western Caribbean. However, it sinks in the eastern Caribbean, producing the "John Hope Rule" effect. Thus cyclone formation is greatly hindered in the Eastern Caribbean, but enhanced in the Western Caribbean, because of the "lift" produced by the...land mass...ironically...

Yeah...and we strong hurricanes in the western Caribbean quite often
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Hurricane Dean peaked in the western Caribbean
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Quoting LargoFl:
pilots ejected so could'nt steer the plane but luck was with them, 9 confirmed injured now but there will be a secondary search of each apt and building once its safe and all the fires are out..lord only knows if one of those people was trapped inside when this happened..


They could have set the auto pilot before leaving the F-18.
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Quoting nigel20:
Hurricane Mitch

Some of the strongest hurricanes in the atlantic occured in the western Caribbean


Don't forget Felix and Dean.

Plus Camille also went through the same area, but obviously hooked much harder northwards.

edit:

Camille formed in that area, but didn't really "power up" until in the Gulf, so maybe not the best example.


there is an atmospheric reason for this, which is ironically related to the John Hope rule.

The air moving over Mexico and Central America is forced upward, producing extra lift in the western Caribbean. However, it sinks in the eastern Caribbean, producing the "John Hope Rule" effect. Thus cyclone formation is greatly hindered in the Eastern Caribbean, but enhanced in the Western Caribbean, because of the "lift" produced by the...land mass...ironically...
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Quoting washingtonian115:
Mmmm I noticed that some of the strongest storms in history have always formed in the northwest carribean....


I think because the Caribbean has the highest heat content in the Atlantic basin.
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yeppers
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Hope this nice little cluster of storms hit me... wouldn't mind a small distraction from work.
Member Since: July 18, 2010 Posts: 50 Comments: 1909
Quoting RTSplayer:


Over water, yes.

But as far as I've ever been able to determine, Labor Day Hurricane 1935 is still by far the strongest known landfall of a TC anywhere in the world.

There have been several stronger storms over water in the modern era, especially in the pacific, but none of them made landfall this strong, as far as I'm aware...

"A landfall intensity of 200 mph makes it both the most intense land-falling hurricane and hurricane in general on record in the Western Hemisphere in terms of maximum sustained wind speed. The recorded central pressure was reported as 26.35 inHg (892 mbar hPa). This was the record low pressure for a hurricane anywhere in the Western Hemisphere until surpassed by Hurricane Gilbert in 1988 and Hurricane Wilma in 2005." - Wiki article.

That's a nice article
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Quoting nigel20:

Yeah...I would want be be at the coast with hurricane as strong as Gilbert and Wilma


I bet you wouldn't after you live through it....probably extremly vicious conditions....
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Mmmm I noticed that some of the strongest storms in history have always formed in the northwest carribean....
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Hurricane Mitch

Some of the strongest hurricanes in the atlantic occured in the western Caribbean
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Quoting NCHurricane2009:
Yep...the hurricanes that rapidly deepen into the upper 800s of mb (like Wilma and Gilbert) seem to show a remarkably small pinhole eye at the time of intensfication.

Yeah...I would want be be at the coast with hurricane as strong as Gilbert and Wilma
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Quoting nigel20:

Yes it does...Gilbert looks like the perfect hurricane from that pic. After crossing Jamaica Gilbert rapidly strengthen to a cat 4 and later became the strongest hurricane in the atlantic...now the second strongest. Hurricane Gilbert was quite large as well


Over water, yes.

But as far as I've ever been able to determine, Labor Day Hurricane 1935 is still by far the strongest known landfall of a TC anywhere in the world.

There have been several stronger storms over water in the modern era, especially in the pacific, but none of them made landfall this strong, as far as I'm aware...

"A landfall intensity of 200 mph makes it both the most intense land-falling hurricane and hurricane in general on record in the Western Hemisphere in terms of maximum sustained wind speed. The recorded central pressure was reported as 26.35 inHg (892 mbar hPa). This was the record low pressure for a hurricane anywhere in the Western Hemisphere until surpassed by Hurricane Gilbert in 1988 and Hurricane Wilma in 2005." - Wiki article.
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Quoting swampdooogggg:

They call that a pinhole eye.
Thanks Tazz. lol/jk
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Quoting swampdooogggg:

They call that a pinhole eye.

I know
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Yep...the hurricanes that rapidly deepen into the upper 800s of mb (like Wilma and Gilbert) seem to show a remarkably small pinhole eye at the time of intensfication.
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Hurricane Wilma

Wilma's eye was extremely small!
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The 18Z GFS has trended much more bullish with the 04/14-04/17 "outbreak" and is now more in line with the ECMWF.

Member Since: July 6, 2010 Posts: 113 Comments: 32811
Quoting NCHurricane2009:
El Nino seems to be recently on a 3 to 4 year frequency based on the last few hurricane seasons when we had one (seasons...2009...2006...2002). I guess then its not surprising that El Nino could pop up during this 2012 season like CSU is saying...

Its also odd that the Atlantic naming list that will be used this year (the one that starts with Alberto) gets "bad luck" such that many of the names on that list never get used

2012--> El Nino?
2006--> El Nino
2000--> A year we finally get far down this name list, ending with Nadine that year
1994--> Cold AMO (Atlantic Multidecadal Oscillation) and moderate El Nino
1988--> Another year we get down this name list, making it to Keith (this was also the year of Gilbert which got retired)
1982--> First year this naming list was used. El Nino & Cold AMO only allow five names to be used on the list
I had pointed this out earlier this year that this naming list has bad luck when it comes to El nino.I generally like the names on the list.Like Oscar...and Issac..
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Quoting TropicalAnalystwx13:
Gilbert looks almost like Wilma, doesn't it?


Yes it does...Gilbert looks like the perfect hurricane from that pic. After crossing Jamaica Gilbert rapidly strengthen to a cat 4 and later became the strongest hurricane in the atlantic...now the second strongest. Hurricane Gilbert was quite large as well
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Gilbert looks almost like Wilma, doesn't it?

Member Since: July 6, 2010 Posts: 113 Comments: 32811
Quoting NCHurricane2009:


I should add that there was a weak El Nino towards the end of the 2004 season...but that didn't affect the 2004 season really.

So I guess its more appropriate to say the recent frequency of which Atlantic hurricane season gets affected by El Nino is 3 to 4 years...so 2012 would fit that trend if El Nino suppresses it as well.

Gilbert (which was replaced with Gordon) was the ONLY name that was retired on the list we are going to use this year. Of the six Atlantic naming lists, this one really doesn't get that much "action" as stated in post 510.

Gilbert was the last hurricane to hit Jamaica...it was a strong cat 3 upon Impact and its the most costly storm in Jamaica's history. Most of the warming in 2004 took place in the central pacific making 2004 a modiki el nino year(Japanese word for same, but different)..
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Quoting NCHurricane2009:


I should add that there was a weak El Nino towards the end of the 2004 season...but that didn't affect the 2004 season really.

So I guess its more appropriate to say the recent frequency of which Atlantic hurricane season gets affected by El Nino is 3 to 4 years...so 2012 would fit that trend if El Nino suppresses it as well.

Gilbert (which was replaced with Gordon) was the ONLY name that was retired on the list we are going to use this year. Of the six Atlantic naming lists, this one really doesn't get that much "action" as stated in post 510.

Just a note, but the 2004 season reached the El Niño criteria in June.

If we do indeed see an El Niño this season, I do not think it will be a typical one. Vertical instability is much, much higher this year compared to previous years, the West Atlantic is much wetter, and Sea Surface Temperatures are much warmer.
Member Since: July 6, 2010 Posts: 113 Comments: 32811
Quoting yqt1001:
First sign of an El Nino.

Central pacific invest.



On a La Nina year your lucky to get 1 or 2 of these..in the summer let alone in April. :P


that storm is surely becoming a tropical cyclone (Pewa) is east of the 180 degree DL..
hopefully they won't f*c*k it up!


1001 MB
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