CSU: expect a quiet 2012 Atlantic hurricane season; EF-3 tornado confirmed in Texas
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
Reader Comments
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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.
You are right as we only need a week or two of favourable conditions to produce one or two dangerous Hurricanes
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".
Thanks, yes it is a nebula but I have forgotten which one. Maybe you can ID if for me!
No, I cannot tell you which one it is, but it's very nice
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
Nice info
Beat me to it. Only ones I found with those colors were Carina and Orion. Didn't know of that TinEye tool. Bookmarked that one for sure. Thanks for posting that helpful tool.
NATIONAL WEATHER SERVICE BLACKSBURG VA
329 PM EDT FRI APR 6 2012
...FREEZING CONDITIONS LATE TONIGHT AND EARLY SATURDAY MORNING...
.CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT. WITH
CLEAR SKIES...AND DIMINISHING WINDS...TEMPERATURES WILL DROP TO
AT OR BELOW THE FREEZING MARK ACROSS MUCH OF THE AREA.
NCZ001-018-VAZ010>020-022>024-034-035-044>047-058 -059-WVZ042>045-
070330-
/O.CON.KRNK.FZ.W.0002.120407T0600Z-120407T1400Z/
ASHE-WATAUGA-BLAND-GILES-WYTHE-PULASKI-MONTGOMERY -GRAYSON-CARROLL-
FLOYD-CRAIG-ALLEGHANY VA-BATH-ROANOKE-BOTETOURT-ROCKBRIDGE-
BEDFORD-AMHERST-PITTSYLVANIA-CAMPBELL-APPOMATTOX- BUCKINGHAM-
HALIFAX-CHARLOTTE-MERCER-SUMMERS-MONROE-GREENBRIE R-
INCLUDING THE CITIES OF...WEST JEFFERSON...BOONE...BLAND...
PEARISBURG...WYTHEVILLE...RADFORD...PULASKI...BLA CKSBURG...
INDEPENDENCE...WHITETOP...TROUTDALE...VOLNEY...GA LAX...FLOYD...
NEW CASTLE...CLIFTON FORGE...COVINGTON...HOT SPRINGS...ROANOKE...
SALEM...FINCASTLE...LEXINGTON...BUENA VISTA...BEDFORD...AMHERST...
DANVILLE...LYNCHBURG...APPOMATTOX...SOUTH BOSTON...KEYSVILLE...
BLUEFIELD...FLAT TOP...HINTON...HIX...UNION...LEWISBURG...
QUINWOOD...DUO...RAINELLE
329 PM EDT FRI APR 6 2012
...FREEZE WARNING REMAINS IN EFFECT FROM 2 AM TO 10 AM EDT
SATURDAY...
* LOCATIONS...THE NORTH CAROLINA MOUNTAINS...MOST OF SOUTHWEST
VIRGINIA...AND SOUTHEAST WEST VIRGINIA.
* HAZARDS...FREEZING TEMPERATURES AND FROST.
* TEMPERATURES...UPPER 20S TO LOWER 30S.
* IMPACTS...DAMAGE TO UNPROTECTED VEGETATION.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL CROPS AND OTHER
SENSITIVE VEGETATION.
&&
$$
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.
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
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.
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)..
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
Wilma's eye was extremely small!
I know
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.
Yeah...I would want be be at the coast with hurricane as strong as Gilbert and Wilma
Some of the strongest hurricanes in the atlantic occured in the western Caribbean
I bet you wouldn't after you live through it....probably extremly vicious conditions....
That's a nice article
Hope this nice little cluster of storms hit me... wouldn't mind a small distraction from work.
I think because the Caribbean has the highest heat content in the Atlantic basin.
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...
They could have set the auto pilot before leaving the F-18.
Yeah...and we strong hurricanes in the western Caribbean quite often
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:
THE SKY IS FALLING! THE SKY IS FALLING!
Land interaction.
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...
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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