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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Quoting hurricanehunter27:
The post he is comparing is from December of 2011 not April. There is nothing you cant take from that post except the water is colder in December.

You are right...the sst anomaly chart gives one a better idea of what is happening
Member Since: November 6, 2010 Posts: 11 Comments: 8317
Quoting Tropicsweatherpr:


Keeper,that is a notable difference that for sure will cause the EPAC season to be very active.
The post he is comparing is from December of 2011 not April. There is nothing you cant take from that post except the water is colder in December. Keep, if you want to make a good comparison get a map of the same month a nino occurred.
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Quoting StormGoddess:
Thanks Dr. Masters.
Glad that we are expecting a quiet season this year.
Happy Easter everybody!

Happy Easter to you too.Don't let down your guard because forecasters are predicting an average to below average hurricane season...though we may have less storm when compared to the past two hurricane season, we may get more impacts this season
Member Since: November 6, 2010 Posts: 11 Comments: 8317
April 4, 2011

April 5, 2012
Member Since: November 6, 2010 Posts: 11 Comments: 8317
Quoting Tropicsweatherpr:


Keeper,that is a notable difference that for sure will cause the EPAC season to be very active.
shear already dropped in the se regions of epac by southern cen america and nw south america east that season is 37 days away its getting closer now




Member Since: July 15, 2006 Posts: 175 Comments: 54847
Quoting KEEPEROFTHEGATE:



The wind shear in the central and eastern tropical atlantic is very high at the moment
Member Since: November 6, 2010 Posts: 11 Comments: 8317
Thanks Dr. Masters.
Glad that we are expecting a quiet season this year.
Happy Easter everybody!
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Quoting KEEPEROFTHEGATE:
nino compare maps dec 2011 april 2012



That's a big difference
Member Since: November 6, 2010 Posts: 11 Comments: 8317
Quoting KEEPEROFTHEGATE:
nino compare maps dec 2011 april 2012




Keeper,that is a notable difference that for sure will cause the EPAC season to be very active.
Member Since: April 29, 2009 Posts: 75 Comments: 14559
nino/nina region compare maps dec 2011 april 2012


Member Since: July 15, 2006 Posts: 175 Comments: 54847
Quoting WxGeekVA:




Pay no attention to the man behind this curtain...




LOL



open it and you may find me in a dress
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Quoting FrankZapper:
You seen JFV lately?




Pay no attention to the man behind this curtain...
Member Since: September 3, 2011 Posts: 13 Comments: 3476
Quoting Tazmanian:
wind shear is still high


Member Since: July 15, 2006 Posts: 175 Comments: 54847
April 6, 2011

April 6, 2012

Member Since: November 6, 2010 Posts: 11 Comments: 8317
Quoting Tazmanian:
am here i come and i go
You seen JFV lately?
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Quoting StormTracker2K:


Did you see any storms in S FL on Friday? I don't know about you guys in GA but we in FL need rain bad and I don't know when we will see rain again. Maybe not until 9 or 10 days from now.


yah on friday there were a few warnings and some heavy rain, today i am in tampa.
The beach was nice and warm, tomorrow i go back to GA.
It is actually a little chilly right now.
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Quoting tropicfreak:


The winter of 09-10 had an El Nino that was very strong, prob something we won't see for another 10-20 years.
Not even that I think.
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Quoting GeorgiaStormz:
i hope this next system trends south instead of so far north.
lifting north is a may/june pattern, not an april one


Did you see any storms in S FL on Friday? I don't know about you guys in GA but we in FL need rain bad and I don't know when we will see rain again. Maybe not until 9 or 10 days from now.
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Quoting TropicalAnalystwx13:

No clue what post you are referring to, could you be more specific? :P

Post 811
Member Since: November 6, 2010 Posts: 11 Comments: 8317
wind shear is still high
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Quoting TropicalAnalystwx13:

A tornado producing supercell.

I hope there were no damage reports
Member Since: November 6, 2010 Posts: 11 Comments: 8317
i hope this next system trends south instead of so far north.
lifting north is a may/june pattern, not an april one
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hurricane season is a bust this year
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am here i come and i go
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Quoting Articuno:

Not much, it was actually a quiet day.

Ok, thanks
Member Since: November 6, 2010 Posts: 11 Comments: 8317
Quoting nigel20:

Is that hurricane Dean?

No clue what post you are referring to, could you be more specific? :P
Member Since: July 6, 2010 Posts: 113 Comments: 32524
Quoting StormTracker2K:
Rays taking care of business!


For now. Let's wait until September and see who is where. (hint: it will be a team that rhymes with Zankees winning the division)
Member Since: September 3, 2011 Posts: 13 Comments: 3476
Quoting nigel20:
What did I miss today?

A tornado producing supercell.
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Quoting TropicalAnalystwx13:

Is that hurricane Dean?
Member Since: November 6, 2010 Posts: 11 Comments: 8317
Quoting Tropicsweatherpr:


Last CPC update on April 2 has Nino 3.4 at -0.2C and that is up from -0.5C on prior update.

Link


La-Nina is gone and were on our way to El-nino.
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Rays taking care of business!
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Quoting washingtonian115:
D.C weather just goes with the flow :).But the mets are not willing to eat crow. Oh n o a winter like that I read comes every 6,000-10,000 years.So won't be expecting another one like that in my life time.


The winter of 09-10 had an El Nino that was very strong, prob something we won't see for another 10-20 years.
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Quoting nigel20:
What did I miss today?

Not much, it was actually a quiet day.
Member Since: October 22, 2011 Posts: 0 Comments: 2543
Quoting tropicfreak:


Sorry, haven't been on this blog since last hurricane season lol.

Welcome back.
Member Since: October 22, 2011 Posts: 0 Comments: 2543
Quoting tropicfreak:


Well, that DCers for ya. Mets here are willing to eat crow, but I don't think they should. Forecasting winter weather here in Richmond is like hitting a pinata blindfolded. It's just so unpredictable. Sometimes that may be good, or bad.
D.C weather just goes with the flow :).But the mets are not willing to eat crow.
Quoting tropicfreak:


El Nino does generally favor an active winter for the eastern US, in this case maybe not like 09-10, but something to be reckoned with.
Oh n o a winter like that I read comes every 6,000-10,000 years.So won't be expecting another one like that in my life time.
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What did I miss today?
Member Since: November 6, 2010 Posts: 11 Comments: 8317
Quoting Articuno:

I personally don't want to know. lol.


Sorry, haven't been on this blog since last hurricane season lol.
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Quoting tropicfreak:


What is with Taz?

I personally don't want to know. lol.
Member Since: October 22, 2011 Posts: 0 Comments: 2543
Quoting TropicalAnalystwx13:

How is hitting a pinata unpredictable? You hit it and candy falls out. :P


Meaning, you don't know if you will hit it or not, or even what you will hit. Ok more like pin the donkey.
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Good day all!
I hope everyone is having a happy Easter......
Member Since: November 6, 2010 Posts: 11 Comments: 8317
Quoting tropicfreak:


Well, that DCers for ya. Mets here are willing to eat crow, but I don't think they should. Forecasting winter weather here in Richmond is like hitting a pinata blindfolded. It's just so unpredictable. Sometimes that may be good, or bad.

How is hitting a pinata unpredictable? You hit it and candy falls out. :P
Member Since: July 6, 2010 Posts: 113 Comments: 32524
Quoting help4u:
Taz will return!!!!I BIT ONN ITT!!!!!!!!!!


What is with Taz?
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Quoting washingtonian115:
I was ashame.And then to make matters worst Doug on channel 4 was bragging about how he was right about the "winter that never was".I wanted to jump into the T.V screen to choke him!.He can have a very cocky attitude at times..


Well, that DCers for ya. Mets here are willing to eat crow, but I don't think they should. Forecasting winter weather here in Richmond is like hitting a pinata blindfolded. It's just so unpredictable. Sometimes that may be good, or bad.
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Taz will return!!!!I BIT ONN ITT!!!!!!!!!!
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Quoting washingtonian115:
I think we had something similar to that.If a El nino does form I hope it makes up for the lame snow totals.


El Nino does generally favor an active winter for the eastern US, in this case maybe not like 09-10, but something to be reckoned with.
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Quoting tropicfreak:


To be honest, by the beginning of Feb I never even thought that we would even see a measurable snowfall here in Richmond. Now I guess we earn bragging rights since we've received more snow than most of the big cities in the NE.
I was ashame.And then to make matters worst Doug on channel 4 was bragging about how he was right about the "winter that never was".I wanted to jump into the T.V screen to choke him!.He can have a very cocky attitude at times..
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Quoting washingtonian115:
We didn't even have 6 inches as the final winter snow amount here in D.C.Quite pitiful if you ask me.


To be honest, by the beginning of Feb I never even thought that we would even see a measurable snowfall here in Richmond. Now I guess we earn bragging rights since we've received more snow than most of the big cities in the NE.
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None are visible right now, but here is a friendly reminder:

Member Since: September 3, 2011 Posts: 13 Comments: 3476
Quoting help4u:
what happen to taz?does he still post?


well

toz has othr stuff to do and ca't be on hair all the time and has a lie outsid wunderworld

i tried to write it in tazs own words the best i could


lol
Member Since: July 15, 2006 Posts: 175 Comments: 54847
Quoting WxGeekVA:


I had a grand total of 2.3 inches for the winter.
I think we had something similar to that.If a El nino does form I hope it makes up for the lame snow totals.
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TORNADO WARNING
NATIONAL WEATHER SERVICE SAN ANGELO TX
802 PM CDT SAT APR 7 2012

THE NATIONAL WEATHER SERVICE IN SAN ANGELO HAS ISSUED A

* TORNADO WARNING FOR...
NORTHWESTERN IRION COUNTY IN WEST CENTRAL TEXAS...

* UNTIL 815 PM CDT

* AT 757 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
TORNADO WAS OVER EXTREME NORTHWESTERN IRION COUNTY...OR 24 MILES
NORTHEAST OF BIG LAKE...MOVING SOUTH SOUTHWEST AT 15 MPH. THIS
STORM HAS A HISTORY OF PRODUCING A TORNADO AND MAY PRODUCE A
TORNADO AT ANY TIME.

IN ADDITION TO DANGEROUS TORNADIC WINDS...OTHER HAZARDS INCLUDE...
LARGE DAMAGING HAIL UP TO TENNIS BALL SIZE.
DAMAGING STRAIGHT LINE WINDS IN EXCESS OF 60 MPH.
POTENTIALLY DEADLY LIGHTNING.

*THE TORNADO WILL REMAIN OVER MAINLY RURAL AREAS OF...
NORTHWESTERN IRION COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT
SATURDAY EVENING FOR WEST CENTRAL TEXAS.
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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.