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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Yes,I did that and all is fine.
Lemme guess...your in Raleigh?
I moved from there to SE Michigan last summer...its 39 here so I wanted to see how things back at home were....and they're not much better right now...LOL
Nah, I am in Wilmington. It wont even get out of the 50's today here.
From about SC north will be in for a shock next week as it will really get cold.
gonna have to drive through this on the way to Tampa Bay.
I hope i intersect a severe thunderstorm with golfball and 70mph. or a freak tornado.
none of them are really likely :(
I don't believe the cool air later next week will materialize for Florida, I said this 2 days ago and I stand by it now. It might cool down for a little, but I highly doubt we will be seeing some big cool down with below normal temps, I expect it just to bring more comfortable, "normal" temps for this time of year like what is moving through this weekend.
Good suggestion Taz, but I can't install any other browser at work. Not allowed. So it's messed up for me when I read now.
it's pretty darned chilly @ Folly Beach right now...
I wish he would just link. It's not that we don't appreciate his efforts; it's just the videos screw up the blog. I've had him on ignore for a while, which is sad because I appreciate his comments.
and then on the GFS it dies.
Pooooooof..........
Issued by The National Weather Service
Binghamton, NY
Fri, Apr 6, 2012, 10:03 AM EDT
Local Temperature Map
Updated Apr 6, 2012, 11:05am EDT
Weather in Motion® | Enlarge Map Get WeatherReadyWhen a Wildfire Threatens
What to Do After a Wildfire
Prepare for Wildfires
Facts About Wildfires
More Information About Wildfires
... RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM EDT THIS EVENING FOR ALL OF NORTHEAST PENNSYLVANIA...
* WIND... NORTHWEST INCREASING TO 15 TO 25 MPH... WITH OCCASIONAL HIGHER GUSTS.
* HUMIDITY... FALLING TO BETWEEN 15 AND 25 PERCENT THIS AFTERNOON.
* IMPACTS... ANY UNCONTROLLED FIRES THAT DEVELOP MAY SEE EXTREME FIRE BEHAVIOR. OUTDOOR BURNING IS NOT RECOMMENDED.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS ARE EITHER OCCURRING NOW... OR WILL SHORTLY. A COMBINATION OF STRONG WINDS... LOW RELATIVE HUMIDITY... AND WARM TEMPERATURES WILL CREATE EXPLOSIVE FIRE GROWTH POTENTIAL.
NATIONAL WEATHER SERVICE MIAMI FL
1121 AM EDT FRI APR 6 2012
FLZ070-071-061545-
INLAND BROWARD COUNTY FL INLAND COLLIER COUNTY FL
1121 AM EDT FRI APR 6 2012
THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A
* SIGNIFICANT WEATHER ADVISORY FOR...
EXTREME WEST CENTRAL BROWARD COUNTY
EAST CENTRAL COLLIER COUNTY
* UNTIL 1145 AM EDT
* AT 1115 AM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM 8 MILES NORTHWEST OF BIG CYPRESS NATIONAL
PRESERVE...AND MOVING EAST AT 25 MPH.
* THE STORM WILL AFFECT...
BIG CYPRESS NATIONAL PRESERVE...
MILE MARKER 60 ON ALLIGATOR ALLEY...
AND SURROUNDING COMMUNITIES.
FREQUENT TO EXCESSIVE LIGHTNING...GUSTY WINDS FROM 45 T0 55 MPH...UP
TO NICKEL-SIZED HAIL...TORRENTIAL DOWNPOURS...OR A COMBINATION OF
THESE ARE POSSIBLE. LIGHTNING IS THE NUMBER ONE WEATHER RELATED
KILLER IN FLORIDA. TREES AND OPEN SHELTERS OFFER NO PROTECTION. THESE
WINDS CAN DOWN SMALL TREE LIMBS AND BRANCHES...AND BLOW AROUND
UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE BUILDING UNTIL THE
STORM PASSES.
LAT...LON 2622 8088 2599 8087 2601 8124 2618 8122
TIME...MOT...LOC 1521Z 275DEG 22KT 2610 8113
$$
AK
Just report and ignore people...report and ignore.
ALERT! ALERT! ALERT! This is the user I warned you about earlier. He is a troll- StormTrackr2K is not StormTracker2K
NATIONAL WEATHER SERVICE MIAMI FL
1139 AM EDT FRI APR 6 2012
FLZ067-068-071-072-168-172-061615-
COASTAL BROWARD COUNTY FL COASTAL PALM BEACH COUNTY FL INLAND BROWARD
COUNTY FL INLAND PALM BEACH COUNTY FL METRO BROWARD COUNTY FL METRO
PALM BEACH COUNTY FL
1139 AM EDT FRI APR 6 2012
THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A
* SIGNIFICANT WEATHER ADVISORY FOR...
NORTHEASTERN BROWARD COUNTY
SOUTHEASTERN PALM BEACH COUNTY
* UNTIL 1215 PM EDT
* AT 1134 AM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM NEAR CORAL SPRINGS...AND MOVING EAST AT 40 MPH.
* THE STORM WILL AFFECT...
COCONUT CREEK...
DEERFIELD BEACH...
LIGHTHOUSE POINT...
AND SURROUNDING COMMUNITIES.
THE PRIMARY IMPACTS WILL BE UP TO NICKEL SIZED HAIL AND GUSTY WINDS
OF 45 TO 55 MPH. THESE WINDS CAN DOWN SMALL TREE LIMBS AND
BRANCHES...AND BLOW AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A
SAFE BUILDING UNTIL THE STORM PASSES.
LAT...LON 2618 8009 2616 8036 2636 8037 2641 8006
2637 8006
TIME...MOT...LOC 1539Z 261DEG 33KT 2628 8023
$$
AK
Any rain by you this morning as I saw some pretty nasty cells heading your way earlier?
Good morning friend! It looks as if some hefty severe wx events are on the horizon for the midwest. This cool snap next week is what seems to be creating more buckling of the jetstream out west and as it comes east later next week then watch out. Look at day 10 on the Euro.
Is that normal?
I was kind of wondering the same thing...
MESOSCALE DISCUSSION 0469
NWS STORM PREDICTION CENTER NORMAN OK
1046 AM CDT FRI APR 06 2012
AREAS AFFECTED...SE FLORIDA COASTAL AREAS
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 061546Z - 061715Z
GENERALLY WEAK LOW-LEVEL CONVERGENCE OVER THE INTERIOR SOUTHERN
FLORIDA PENINSULA PROBABLY WILL CONTINUE TO LIMIT THE CONVECTIVE
POTENTIAL TODAY. BUT A WEAK PRE-FRONTAL CONFLUENCE ZONE APPEARS TO
BE FORMING ALONG A EAST-WEST AXIS ACROSS PARTS OF COLLIER AND
BROWARD COUNTIES...WHICH COULD BECOME A FOCUS FOR CONVECTIVE
DEVELOPMENT/INTENSIFICATION DURING THE NEXT COUPLE OF HOURS. IN THE
PRESENCE OF SIZABLE CAPE OF 2000+ J/KG...DEEP LAYER VERTICAL SHEAR
IS STRONG BENEATH 40-50 KT WEST NORTHWESTERLY 500 MB FLOW. ISOLATED
SUPERCELL DEVELOPMENT APPEARS A POSSIBILITY BY 17-18Z...
PARTICULARLY NEAR EASTERN BROWARD COUNTY COASTAL AREAS. WITH THE
SEA-BREEZE LIKELY TO REMAIN OFFSHORE...TORNADIC POTENTIAL OVER
INLAND AREAS SEEMS LOW...BUT LARGE HAIL IS POSSIBLE...ALONG WITH
SOME RISK FOR A LOCALLY STRONG WIND GUST OR TWO.
..KERR.. 04/06/2012
No, that is a low pressure area that will move into the United States within the next few days.
This is Invest 90C.
That is to be expected in my opinion.
Unusually warm weather resulted in the warmest March on record in most of central and southeast Illinois, with monthly average temperatures as much as 16 degrees above normal. The image above, from the Midwestern Regional Climate Center, shows the departure from normal for average temperatures across the Midwest.
That west coast low look real deep
One way to get around this is to get VirtualBox or VMWare player installed on your machine, get one of the free main-line linux virtual machines out there (distributed as appliances) and use firefox or chrome from within the VM.
Within the virtual machine you have admin rights so you can do whatever you want, and if it gets wrecked your normal OS remains unscathed.
This assumes of course that:
1. You can install a virtual machine manager like VirtualBox or VMWare player.
2. You have the hardware capable for running a VM (you usually want to set aside at least a GB or two and at least one cpu core to the VM).
The mainline linux distros like Ubuntu are pretty user friendly these days, and they usually come with firefox pre-installed.
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