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

Share this Blog
38
+

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

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1166 - 1116

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26Blog Index

Quoting Tropicsweatherpr:
Nrt, another question,this one related to 90C. Why after crossing into the Western Pacific is still 90C and not a WPAC invest?


They must be treating it as an "unnamed tropical depression" per National Hurricane Operations Plan:

An unnamed tropical depression will also retain its number (e.g.
Tropical Depression Six-E remains Tropical Depression Six-E) if it crosses into another area of
responsibility.
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

It is according to the Joint Typhoon Warning Center (JTWC). However, according to the Japan Meteorological Agency (JMA), it is a tropical depression.

I think I prefer JTWC here.



TS JOSE REBORN!!!

Member Since: Posts: Comments:
1164. KEEPEROFTHEGATE (Mod)
ABPW10 PGTW 081500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS REISSUED/081500Z-090600ZAPR2012//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION HAS PERSISTED NEAR 17.3N 178.5E,
APPROXIMATELY 680 NM EAST OF WAKE ISLAND. ANIMATED INFRARED
SATELLITE IMAGERY SHOWS FLARING CONVECTION NEAR THE LOW-LEVEL
CIRCULATION CENTER (LLCC) WITH PERIPHERAL BANDS OVER THE EASTERN
SEMICIRCLE. A SERIES OF SCATTEROMETRY PASSES INDICATE CENTRAL WINDS
OF 10-15 KNOTS WITH STRONGER GRADIENT INDUCED PERIPHERAL WINDS OVER
THE NORTHERN AND EASTERN QUADRANTS, APPROXIMATELY 1.5-2.0 DEGREES
REMOVED FROM THE LLCC. A 080901Z AMSU-B IMAGE DEPICTS A SMALL DEEP
CONVECTIVE CLUSTER APPROXIMATELY 90 NM TO THE NORTH OF THE LLCC.
ANIMATED TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE LLCC TO BE
NEARLY COCOONED BY A RELATIVELY DRIER AIR MASS WITH LIMITED MOIST
AIR ENTRAINMENT PROVIDED BY TRADE WIND FLOW. ANIMATED WATER VAPOR
IMAGERY CLEARLY DEPICTS THE SUBSIDENT DRY AIRMASS THAT SURROUNDS
THE LLCC. THE MOST RECENT AMSU CROSS-SECTION (070900Z) REVEALS A
WEAK WARM CORE ANOMALY THAT IS HORIZONTALLY LARGE AND DISPLACED
HIGHER IN THE TROPOSPHERE THAN WHAT IS NORMALLY SEEN FOR A TYPICAL
WARM CORE TROPICAL DISTURBANCE. THEREFORE, DUE TO THE WEAK CENTRAL
WINDS, DISPLACED CONVECTION, AND TEMPERATURE CHARACTERISTICS, THIS
DISTURBANCE IS CLASSIFIED AS A SUB-TROPICAL SYSTEM. MODEL GUIDANCE
DOES NOT SUGGEST A TRANSITION INTO A WARM CORE TROPICAL SYSTEM BUT
RATHER OPENS THE CIRCULATION INTO A WAVE OVER THE NEXT FEW DAYS.
UPPER-LEVEL ANALYSIS SHOWS A CYCLONIC CIRCULATION POSITIONED
DIRECTLY OVER THE LLCC. SEA SURFACE TEMPERATURES ARE ON THE LOW
THRESHOLD FOR TROPICAL DEVELOPMENT AT 26-27 DEGREES CELSIUS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1009 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS LOW.
(2) NO OTHER SUSPECT AREAS.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: ADDED AREA IN PARA 1.B.(1) AS A LOW.//
NNNN

Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

I used to think it would be hard to reach El Niño as well, but with the recent jump to -0.2 °C, I think a weak El Niño is definitely within the realms of possibility by July/August.


Infact Dr. Gray even mentions the fact that they are leaning toward the Euro as that model has been predicting this quick increase in SST's for months now across the the E-Pac. I would bet that tomorrow's update will have us in nuetral. Whether people believe it or not on here we are heading for a El-nino question becomes now how strong?
Member Since: Posts: Comments:
1162. Grothar
Quoting nrtiwlnvragn:


Would think the different physics packages and increased resolution in v2.


Yes, it is always good to examine physics packages closely.
Member Since: Posts: Comments:
Quoting weatherh98:


Where is the loft coming from

The what?
Member Since: July 6, 2010 Posts: 113 Comments: 32032
1160. Grothar
Quoting GeoffreyWPB:
Come out from hiding Grothar!


Grothar knows when to come out and play and when to lurk.

Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
Some very large hail is possible tomorrow...that seems to be a theme this Severe Weather season.





Where is the lift coming from
Member Since: June 17, 2011 Posts: 11 Comments: 6493
Quoting Tropicsweatherpr:
Nrt, another question,this one related to 90C. Why after crossing into the Western Pacific is still 90C and not a WPAC invest?

It is according to the Joint Typhoon Warning Center (JTWC). However, according to the Japan Meteorological Agency (JMA), it is a tropical depression.

I think I prefer JTWC here.

Member Since: July 6, 2010 Posts: 113 Comments: 32032
1157. KEEPEROFTHEGATE (Mod)
Quoting nrtiwlnvragn:
National Multi-Model Ensemble (NMME). Models: NCEP coupled forecast system model (CFSv1), NCEP coupled forecast system model 2 (CFSv2), ECHAMA, ECHAMF, GFDL, NCAR, NASA still forecasting an El Nino


the question is how long do we take to get to the full event
Member Since: Posts: Comments:
My blog is messed up?
Member Since: June 17, 2011 Posts: 11 Comments: 6493
Quoting HadesGodWyvern:
Japan Meteorological Agency
Tropical Disturbance Summary
TROPICAL DEPRESSION XX
3:00 AM JST April 9 2012
=====================================

Tropical Depression Near Midway Island

At 18:00 PM UTC, Tropical Depression (1006 hPa) located at 17.7N 176.5E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The depression is reported as moving west southwest at 18 knots.
I am assuming this is the CPac AOI we were watching last week?

Quoting nofailsafe:


I've already tapered off my driving, 3.87-4.05 here in Houston gives me plenty of reason to take the bus and train. I can take the heat so I don't have a problem with sitting in a bus shelter for 10 minutes waiting. Besides, I can catch up on my reading.
I've also been adjusting my departure / arrival times so that I'm in / out before / after rush hour. This cuts a bundle weekly on the amound of gas I burn. Even minimizing extra trips to the grocery store etc helps. I know walking in urban Texas is not necessarily a good choice [distance-wise], but outside of the summer it can be a practical solution in Nassau.
Member Since: Posts: Comments:
Nrt, another question,this one related to 90C. Why after crossing into the Western Pacific is still 90C and not a WPAC invest?
Member Since: Posts: Comments:
Some very large hail is possible tomorrow...that seems to be a theme this Severe Weather season.



Member Since: July 6, 2010 Posts: 113 Comments: 32032
Quoting GeoffreyWPB:


Why not think for yourself. Take in all sourses of media.


I do, but I use morals instilled in me
Member Since: June 17, 2011 Posts: 11 Comments: 6493
Quoting Tropicsweatherpr:


Why CFS and CFSv2 are different with their forecasts as CFS is in Neutral and CFSv2 is at El Nino by July?


Would think the different physics packages and increased resolution in v2.
Member Since: Posts: Comments:
Quoting weatherh98:


I'm tired of GW talks and arguing over pointless stuff arguing over windspeed is better
Yeah that and where will the storm be going.LOL.Just two more months.
Member Since: Posts: Comments:
Quoting weatherh98:


Nothing is unbiased now adays.. I just happen to agree with one source because of the way I am raised..


Why not think for yourself. Take in all sourses of media.
Member Since: September 10, 2007 Posts: 0 Comments: 11151
1148. geepy86
Quoting TropicalAnalystwx13:
I'm so ready for hurricane season...

I'm not
Member Since: Posts: Comments:
Quoting caneswatch:


Rush is just as biased as any other cable news source. Read unbiased and you'll notice a huge difference.


Nothing is unbiased now adays.. I just happen to agree with one source because of the way I am raised..
Member Since: June 17, 2011 Posts: 11 Comments: 6493
Quoting TropicalAnalystwx13:
I'm so ready for hurricane season...


Only 53 days and counting until June 1rst.

Link
Member Since: Posts: Comments:
Quoting washingtonian115:
Who isn't at this point.


I'm tired of GW talks and arguing over pointless stuff arguing over windspeed is better
Member Since: June 17, 2011 Posts: 11 Comments: 6493
Quoting GeoffreyWPB:
Come out from hiding Grothar!


I know he's out there!
Member Since: Posts: Comments:
Quoting GeoffreyWPB:


Funny he didn't mention Fox.


Yeah I know.
Member Since: Posts: Comments:
Quoting weatherh98:


Well don't pounce on what I listen too


Rush is just as biased as any other cable news source. Read unbiased and you'll notice a huge difference.
Member Since: Posts: Comments:
Come out from hiding Grothar!
Member Since: September 10, 2007 Posts: 0 Comments: 11151
Quoting TropicalAnalystwx13:
I'm so ready for hurricane season...
Who isn't at this point.
Member Since: Posts: Comments:
Quoting nrtiwlnvragn:
National Multi-Model Ensemble (NMME). Models: NCEP coupled forecast system model (CFSv1), NCEP coupled forecast system model 2 (CFSv2), ECHAMA, ECHAMF, GFDL, NCAR, NASA still forecasting an El Nino




Why CFS and CFSv2 are different with their forecasts as CFS is in Neutral and CFSv2 is at El Nino by July?
Member Since: Posts: Comments:
I'm so ready for hurricane season...
Member Since: July 6, 2010 Posts: 113 Comments: 32032
Quoting GeoffreyWPB:


Funny he didn't mention Fox.


Fox is right wing the others are left...
Member Since: June 17, 2011 Posts: 11 Comments: 6493
Quoting GeoffreyWPB:
Hi canes...you are on a roll tonight!


Hi Geoff! I know, my weekend just keeps on going! It definitely was sad to hear of Mike Wallace's passing. I knew he was up there but didn't see it coming.
Member Since: Posts: Comments:
Quoting caneswatch:


Just because I said what I said makes you think I watch that? I just prefer to stick with the newspaper and local TV. I don't watch all of the big network TV news stuff, it's too biased.


Funny he didn't mention Fox.
Member Since: September 10, 2007 Posts: 0 Comments: 11151
Quoting caneswatch:


Just because I said what I said makes you think I watch that? I just prefer to stick with the newspaper and local TV. I don't watch all of the big network TV news stuff, it's too biased.


Well don't pounce on what I listen too
Member Since: June 17, 2011 Posts: 11 Comments: 6493
Quoting weatherh98:


I suppose u watch CNN and msnbc


Just because I said what I said makes you think I watch that? I just prefer to stick with the newspaper and local TV. I don't watch all of the big network TV news stuff, it's too biased.
Member Since: Posts: Comments:
1132. hydrus
Quoting wunderkidcayman:

well don't know about El nino but maybe nutral
It will be late in the year, but its my guess that it will be official by September or October.
Member Since: Posts: Comments:
09 same time



Member Since: Posts: Comments:
Hi canes...you are on a roll tonight!
Member Since: September 10, 2007 Posts: 0 Comments: 11151
Evening all. Did anybody notice this?

7.Aspen, CO set a record high temperature of 63 for Apr 08

9.Craig, CO set a record low temperature of 12 for Apr 08

Just FYI, Aspen and Craig are about 100 miles apart...
Member Since: Posts: Comments:
National Multi-Model Ensemble (NMME). Models: NCEP coupled forecast system model (CFSv1), NCEP coupled forecast system model 2 (CFSv2), ECHAMA, ECHAMF, GFDL, NCAR, NASA still forecasting an El Nino


Member Since: Posts: Comments:
Quoting caneswatch:


An obviously hugely biased person who just hates the Democratic party altogether and tries to smear everything they do. You obviously should listen to non-biased sources.


I suppose u watch CNN and msnbc
Member Since: June 17, 2011 Posts: 11 Comments: 6493
WE NEED RAIN!!!.I Feel like I live in Cali right now with all the gusty winds and bone dry ground...
Member Since: Posts: Comments:
So sad to hear Mike Wallace passed away.
Member Since: September 10, 2007 Posts: 0 Comments: 11151
Quoting hydrus:
It may not be strong, but it is a good bet that El-Nino will show itself. Very unusual to have a La-Nina stick around any longer then it already has.

well don't know about El nino but maybe nutral
Member Since: Posts: Comments:
Quoting weatherh98:


My mom heard it on rush radio...


An obviously hugely biased person who just hates the Democratic party altogether and tries to smear everything they do. You obviously should listen to non-biased sources.
Member Since: Posts: Comments:
Quoting wunderkidcayman:

hey cybrteddy that one is for 2011 not 09


I'm aware.
Member Since: Posts: Comments:
Quoting CybrTeddy:


Another reason why 2009 isn't a good analog year, this time 2009 it was predicted to be a weak El Nino, this year it's predicted to be very warm neutral before going back.

hey cybrteddy that one is for 2011 not 09
Member Since: Posts: Comments:
Quoting caneswatch:


Where does this come from?


My mom heard it on rush radio...
Member Since: June 17, 2011 Posts: 11 Comments: 6493
1119. hydrus
Quoting FrankZapper:
We have analyzed the most recent data and our high level seasonal forecast is 7-2-1.
That would be a slow season indeed...Last one like that was in 92...Still a bad year for a lot of people. P,S. 94 ..my bad..
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

No, both the SOI and Sea Surface Temperatures have fallen, and risen, respectively, more drastically recently.
Member Since: July 6, 2010 Posts: 113 Comments: 32032
Quoting CybrTeddy:


Another reason why 2009 isn't a good analog year, this time 2009 it was predicted to be a weak El Nino, this year it's predicted to be very warm neutral before going back.

I used to think it would be hard to reach El Niño as well, but with the recent jump to -0.2 °C, I think a weak El Niño is definitely within the realms of possibility by July/August.
Member Since: July 6, 2010 Posts: 113 Comments: 32032
Quoting TropicalAnalystwx13:

No, both the SOI and Sea Surface Temperatures have fallen, and risen, respectively, recently.

Ik but the pase of change is less drastic...
Member Since: June 17, 2011 Posts: 11 Comments: 6493

Viewing: 1166 - 1116

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.