Dr. Jeff Masters' WunderBlog

Another wild night in Tornado Alley
Posted by: Dr. Jeff Masters, 11:40 AM GMT on May 06, 2007 +6
The sirens sounded two more times in tornado-ravaged Greensburg, Kansas last night, as two more twisters tore through the county. However, both tornadoes missed populated areas, as did most of the approximately 75 tornadoes that touched down yesterday. The action should quiet down considerably today; the Storm Prediction Center (SPC) has placed most of Kansas and Nebraska under its "Slight Risk" area for severe weather. Sweetwater, Oklahoma received significant damage from a tornado last night, and we've saved 300 Kb animations of the radar reflectivity and Doppler velocities of the tornado.

It will take a long time for Greensburg to recover from Friday's tornado. To get an idea of the scale of devastation, see the aerial photos posted by the Wichita Eagle. Damage surveys are not yet complete on the tornado, but photos I've seen of the destruction show damage consistent with EF4 winds(168-199 mph). It is possible the storm was an EF5 (winds more than 200 mph). The nine deaths from the tornado bring the U.S. tornado death toll to 68 so far this year, two more than the toll for all of last year.

We've saved some extraordinary 1 Mb animations of the radar reflectivity and Doppler velocities of the tornado. I asked wunderground meteorologist and tornado expert Rob Carver to comment on what's going on in the animations, and here was his analysis:

This was likely an example of cyclic mesocyclogenesis. In a nutshell, the rear-flank downdraft surges out, wraps around and occludes the mesocyclone (Meso A for short). Meso A then veers to the left and dies, this is why tornado family members curve to the left as they dissipate. While Meso A is dying, a new meso spins up and becomes the dominant meso. Now, while I've seen plenty of simulated cyclic cases where the hook retreats when Meso A occludes, I don't think I've seen anything as dramatic.



Figure 1. Radar image of the storm that spawned the Greensburg, KS tornado of May 4, 2007, showing the clearly defined hook echo associated with the twister.

Coastal Carolina storm
The latest (8pm EDT) computer forecast models continue to show a moderately strong coastal storm developing several hundred miles southeast of Cape Hatteras, North Carolina, on Monday. The storm will be extratropical in nature when it forms. We'll have a lot of time to watch the storm, as it is expected to meander offshore for five days and gradually weaken. Water temperatures are 22-23 C off of the coast, which may be warm enough to allow the low to acquire some subtropical characteristics and become the season's first named storm. The models are hinting that the storm could remain over water long enough for this to happen, and I put the odds of a Subtropical Storm Andrea forming late this week at about 20%.

Wunderblogger Mike Theiss was out chasing yesterday and caught some of the storms; be sure to tune into his blog over the next few days to read his chase accounts. Stormchaser Dan Robinson posted some video stills of the Greensburg tornado.

Jeff Masters
()
Storm Brewing (thomasanthony)
A big storm moved in on the 3rd. Wasn't as bad as it looked though.
Storm Brewing
Categories: Tornado
  Permalink | A A A
Reader Comments
Display: 0, 50, 100, 200 Sort: Newest First - Order Posted
Viewing: 751 - 801

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19Blog Index

751. lilmax 1:57 AM GMT on May 07, 2007    
Another batch of thunderstorms moving in from the north-northeast. Thankfully it doesn't look so concentrated as the first batch.
752. KoritheMan 1:59 AM GMT on May 07, 2007    
Yeah kris, I agree. Shear will improve, and Andrea might form. The most it'll get I think is 60 mph as a tropical storm, and 45 mph as a subtropical storm.
Member Since: March 7, 2007 Posts: 421 Comments: 15643
753. stormhank 1:59 AM GMT on May 07, 2007    
Hey Kris n Adrian!!! I wonder when or if the GFDL model will start up? It doesnt go year round like the CMC n GFS does it??
Member Since: September 8, 2005 Posts: 0 Comments: 1378
754. weatherboykris 2:00 AM GMT on May 07, 2007    
The GFDL only runs on invests.
Member Since: December 9, 2006 Posts: 125 Comments: 11343
755. lilmax 2:00 AM GMT on May 07, 2007    
You have a point there Jackp0t, but it is about to become a warm-core storm, nor'easters aren't warm-core.
756. kmanislander 2:00 AM GMT on May 07, 2007    
Stormhank

They will crank up the gfdl when an invest is declared
Member Since: August 19, 2006 Posts: 0 Comments: 14988
757. KoritheMan 2:02 AM GMT on May 07, 2007    
Who here thinks Andrea will develop? I give it a 35% chance of occuring.
Member Since: March 7, 2007 Posts: 421 Comments: 15643
758. weatherboykris 2:03 AM GMT on May 07, 2007    
I'll go with 45%.
Member Since: December 9, 2006 Posts: 125 Comments: 11343
762. hurricaneman23 2:05 AM GMT on May 07, 2007    
45%? thats pretty high
763. lilmax 2:06 AM GMT on May 07, 2007    
40% Chance.
764. weatherboykris 2:07 AM GMT on May 07, 2007    
I don't think so...after all,it is May.We aren't THAT far from the start of the season.
Member Since: December 9, 2006 Posts: 125 Comments: 11343
765. pottery 2:07 AM GMT on May 07, 2007    
Where is bouy ..001 ??
Member Since: October 24, 2005 Posts: 0 Comments: 20866
767. FTmyersZ 2:08 AM GMT on May 07, 2007    
Station 41001 - 150 NM East of Cape HATTERAS
Member Since: August 26, 2005 Posts: 0 Comments: 60
768. Patrap 2:09 AM GMT on May 07, 2007    
NDBC Hatteras Buoy Link
Member Since: July 3, 2005 Posts: 377 Comments: 112996
770. pottery 2:10 AM GMT on May 07, 2007    
Thanks
Member Since: October 24, 2005 Posts: 0 Comments: 20866
771. Patrap 2:10 AM GMT on May 07, 2007    
The buoy 5 day plot..graphically..Link
Member Since: July 3, 2005 Posts: 377 Comments: 112996
773. StormJunkie 2:10 AM GMT on May 07, 2007    
Evening all. It is E of Hatteras pottery. Good to see you.

You can find the National Bouy Data center from the marine section here.

All right y'all I am off to bed. Got to work early. Will be intersting to see if it can build some moisture on that western side.
Member Since: August 17, 2005 Posts: 26 Comments: 15240
774. pottery 2:13 AM GMT on May 07, 2007    
.Thanks again.
Member Since: October 24, 2005 Posts: 0 Comments: 20866
775. stormhank 2:12 AM GMT on May 07, 2007    
Wouldnt u all agree though that the GFDL is probably one of the best models?I remember back in 2005 it forecast the SW motion of Katrina over south Fla a day or so before it really happened?
Member Since: September 8, 2005 Posts: 0 Comments: 1378
776. WKendallGuy 2:13 AM GMT on May 07, 2007    
The tornado will be near...
intersection krome and Kendall drive by 845 PM EDT...
Kendall Lakes by 850 PM EDT...
The Hammocks and West Kendall by 855 PM EDT...

I'm in the Hammocks and didn't notice any tornado, the dogs were barking fiercely though. Missed another bullet.

Member Since: August 1, 2006 Posts: 0 Comments: 24
777. Ldog74 2:14 AM GMT on May 07, 2007    
Hows everyone doin tonite. Usual suspects are here, and the heated debates continue. I see we have a potential system to keep an eye on over the next couple of days. I'd give it 25-30%, but count your blessings, if this storm were taking place in '05, it'd probably be a full-fledged hurricane by now.
Member Since: June 11, 2006 Posts: 0 Comments: 165
778. hurricane23 2:18 AM GMT on May 07, 2007    
This lows chance at becoming hybrid or tropical will be within 24-36 hours.
Member Since: May 14, 2006 Posts: 8 Comments: 13331
780. KoritheMan 2:20 AM GMT on May 07, 2007    
cyclonebuster, tornadoes will always occur. No one can stop them. I love life too, but nothing I or anyone else can do about disasters. Keep up the preparation for them, since they WILL continue to happen. I hate complacency more than anything (not offending you or anything).

Also cyclone, WHAT THE HECK is a tunnel? o_O
Member Since: March 7, 2007 Posts: 421 Comments: 15643
781. weatherboykris 2:23 AM GMT on May 07, 2007    
Just don't ask...LOL.BBL
Member Since: December 9, 2006 Posts: 125 Comments: 11343
782. CryptKicker 2:25 AM GMT on May 07, 2007    
Doc, last night's tornado was in Sweetwater, OK, not Sweetwater, TX.
783. RL3AO 2:25 AM GMT on May 07, 2007    
Posted By: KoritheMan at 9:20 PM CDT on May 06, 2007.

Also cyclone, WHAT THE HECK is a tunnel? o_O


Here we go.
785. Bamatracker 2:26 AM GMT on May 07, 2007    
nnooooooooooooooooo....dont ask about the tunnels!!!! LOL
Member Since: May 17, 2006 Posts: 6 Comments: 1364
786. KoritheMan 2:26 AM GMT on May 07, 2007    
I'm sorry if I started anything by asking. Can't someone MAIL me and tell me? I'm really curious.
Member Since: March 7, 2007 Posts: 421 Comments: 15643
787. pottery 2:27 AM GMT on May 07, 2007    
" use our tunnels
to stop those funnels " tm

I'm the marketing dept....................
Member Since: October 24, 2005 Posts: 0 Comments: 20866
788. lilmax 2:27 AM GMT on May 07, 2007    
I'm tired people, all this watching loops of the future system in the Atlantic, watching Tornado Warnings pop up in my side of town and tracking the severe weather in the Central Plains has made me tired. Good night everyone and be safe.
790. stormhank 2:31 AM GMT on May 07, 2007    
new 00Z NAM 48hr..Link
Member Since: September 8, 2005 Posts: 0 Comments: 1378
791. BahaHurican 2:32 AM GMT on May 07, 2007    
If u want a satellite closeup of that cell as it moves off the FL coast, go here.

I notice it seems to be losing power as it slides off the coast, but it still has enough oomph to it it (hopefully) give us a good night's rain shower. I did check car windows and house windows just now to make sure nothing got wet.

One of the advantages of living in the islands is that tornados rarely form here and even more rarely do damage on land. Mostly we see waterspouts, and the rare tornado is usually embedded in a hurricane.
Member Since: October 25, 2005 Posts: 19 Comments: 17961
792. Bamatracker 2:32 AM GMT on May 07, 2007    
well that looks the same...looks like the low is starting to wrap a little
Member Since: May 17, 2006 Posts: 6 Comments: 1364
793. seminolesfan 2:34 AM GMT on May 07, 2007    
buster-I remember when the admins 'requested' that you leave the tunnels out of the underground ,if you'll pardon the pun.


Member Since: June 14, 2006 Posts: 0 Comments: 1864
794. hurricane23 2:36 AM GMT on May 07, 2007    
Right now the NHC has at 1005mb area of low pressure.We'll see what happens over the next day or two.

frr
Member Since: May 14, 2006 Posts: 8 Comments: 13331
795. pottery 2:36 AM GMT on May 07, 2007    
Bahahurican, what are the sea conditions there now ?
Member Since: October 24, 2005 Posts: 0 Comments: 20866
796. stormhank 2:38 AM GMT on May 07, 2007    
66 Hr 00Z NAM.. looks almost stationary?Link
Member Since: September 8, 2005 Posts: 0 Comments: 1378
798. seminolesfan 2:42 AM GMT on May 07, 2007    
you need to be given your meds.
Member Since: June 14, 2006 Posts: 0 Comments: 1864
799. seminolesfan 2:43 AM GMT on May 07, 2007    
f-this; nite all!!!!
Member Since: June 14, 2006 Posts: 0 Comments: 1864
800. KoritheMan 2:43 AM GMT on May 07, 2007    
Would SOMEONE PLEASE mail me and tell me what TUNNELS are??
Member Since: March 7, 2007 Posts: 421 Comments: 15643

Viewing: 751 - 801

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19Blog Index

New Comment
Community Standards Policy Comments will take a few seconds to appear.
Post Your Comments
Please sign in to post comments.
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.
About JeffMasters
Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Community Activity