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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Link
Still shouldnt be closed, this is the first crash since 1986.
What are the reports?
Nothing yet.
Plane took off, all the sudden there were 3 loud popping sounds afterwords the pilots took the plane vertical with no sound, the plane went into the nosedive and the pilots waited for the last possible moment to eject. The pilots aimed the plane for the middle of the courtyard and appears they hit their mark.
The pops were compressor stalls in the engines/engine. If you look at the picture of the crashed aircraft, you will see the left engine's exhaust nozzle is closed, it shouldn't be for takeoff. The right nozzle is open.
This is the season that big birds are flying North in that area. My guess is that the F-18 hit some birds shortly after take off.
I'm glad you know that, im shocked the pilots were able to still aim for a unpopulated area and miss 264.
This has got to be the smallest slight risk area I have ever seen...
Go check out Mesoscale Discussion
#269#469 for the smallest MD ever issued.Glad it appears no fatalities in that crash, sounds like the pilots did a great job getting it down before their last second ejection.
This one?
Oops, lol.
I meant #469.
Like, is that serious? That's like the size of one county! Maybe 1 supercell could fit in there, but is that really worth a discussion?
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
Atmospheric conditions still act like we're in a La Nia. In fact, we are still on the Neutral/La Nia border according to the Climate Prediction Center.
Naw, naw, last April wasn't even a TAD ridiculous.
I think that's more tornadoes than the other 6 years combined!
It's got at least 12 to 36 before it does anything, I think, IF it does develop.
It's still under and upper level cyclone so it's never going to get true tropical characteristics until that gets out of the way.
Heck, right now, the blob of convection 15 degrees south and east is actually stronger than the "invest".
I still think that's kind of a cheap invest... It looks subtropical at best, and that is probably generous, plus it is almost in the West Pac, which as has already been stated can and does see development at this time of year... Certainly not a big deal IMO
2011 was tame before April...at least compared to other years.
These are conformed tornado totals for 2006-2012 for the combined months of January, February, and March.
On top of that, the Central Pacific Hurricane Center is taking no notice of Invest 90C at this time...LOL
http://www.prh.noaa.gov/hnl/cphc/
Link
Reminds me of Tropical Storm Sean from last year.
Like the 3 county Severe Thunderstorm Watch last week in Kansas?? LOL!
Thanks much
I'm happy there are no fatalities
The SST checkbox in that anim shows 26 to 27 deg C waters below Invest 90C. The high-level winds check box confirms the subtropical structure with a cold core upper low above it. If its sufficiently cold (coupled with those warm waters)....t-storms could continue to fire and gradually build a vertical warm core over time. This is a pretty respectable invest actually given the water temps...
The mid-level & low-level winds check boxes shows extensive anticyclonic flow to the north of 90C...signatory of a subtropical ridge (since I don't have a surface map of the area). Looks like then 90C should continue to be pushed west by the ridge into the West-Pac area of responsibility.
That's what I have to repeat endlessly in these blogs.
Link
Here's a link to the West Pacific side of it
From NWS Great Falls:
... Winter Storm Warning remains in effect until 6 am MDT
Saturday...
A Winter Storm Warning remains in effect until 6 am MDT Saturday.
* Timing and main impact: snow will continue through this
afternoon before diminishing tonight.
* Snow accumulations: storm total snow accumulation 5 to 9
inches. 10 to 20 inches in the mountains.
* Winds and visibility: north winds will increase to 10 to 20 mph
with gusts to 30 mph will create localized blowing and drifting
of snow and visibility below one quarter of a mile at times.
* Other impacts: roads will become snow covered and slippery.
Heavy wet snow could cause damage to trees and possible
power outages. Young unprotected livestock could become
stressed.
* Locations affected include: White Sulphur Springs... Boulder...
Boulder Hill... Elk Park Pass... Homestake pass... Whitehall...
Townsend... Great Falls... Kings Hill Pass... Flesher Pass...
Helena... Lincoln... MacDonald Pass... Rogers Pass.
Precautionary/preparedness actions...
A Winter Storm Warning for heavy snow means severe winter weather
conditions are expected or occurring. Significant amounts of snow
are forecast that will make travel dangerous. If you must... keep
an extra flashlight... food... and water in your vehicle in case of
an emergency.
For specific Road and travel conditions in Montana... dial 5 1 1.
???
Just more evidence that the Caribbean and Gulf of Mexico especially will be much more favorable for tropical development as opposed to the open Atlantic and Eastern Atlantic.
He's right.
The amount of damage this is going to do during the next couple generations, maybe even the next several centuries, is going to be a couple orders of magnitude greater than all other man-made disasters in human history combined.
It's not just the loss of property, but the loss of ecosystems and damage to the food supply.
World population may peak around 9 billion or so in a few decades, but God help us, because if the ocean acidification predictions and a simple exponential trend in arctic (and possibly antarctic) melting follows through, it will really be unimaginably different world in 100 to 200 years.
Take a look at the deserts in Africa and the Middle East.
For all we know, what's left of Texas, Louisiana, Mississippi, and Alabama may look like that in 200 years, but you have to adjust also for all the land they will lose from the sea level rise as well.
Hurricanes may be making landfall in an otherwise desertified Arkansas, if they go straight up the Mississippi River.
Imagine a hot summer day under high pressure in Oklahoma or Nebraska, even up into the Dakotas in 200 years, when the Earth's mean temperature is like 6C hotter. It will bake the life right out of plants, just like Death Valley or Gobi desert.
If it gets hot enough, the lakes in Minnesota and even the Great Lakes might dry up in a couple hundred years, and lead to even more massive inland desertification.
Sound far-fetched?
it HAS happened before even in modern times, such as Lake Chad.
There was also several ancient lakes a few thousand years ago in Libya which are now totally evaporated and desertified. that took a few thousand years to happen, but with accelerated global warming due to man made GHG, it might only take a few centuries for similar changes to happen in modern times.
I like your avatar...is that a nebula?
agreed!
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.
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