Greensburg tornado an EF-5; coastal storm will bring 3-5' storm surge to Carolinas

By: Dr. Jeff Masters , 2:42 PM GMT on May 07, 2007

Share this Blog
4
+

The huge, 1.4 mile-wide tornado that devastated Greensburg, KS on Friday night, May 4, was an EF-5 tornado on the Enhanced Fujita Scale. A preliminary damage survey by the National Weather Service found that the storm likely had 205 mph winds, putting it just above the 200 mph wind threshold for an EF5 rating. This is the first tornado ever rated as an EF5 using the new scale, adopted in February of 2007, and the first tornado to receive a "5" rating since the May 3, 1999 Moore-Bridge Creek tornado that devastated the southern suburbs of Oklahoma City. Had the Greensburg tornado hit downtown Chicago, the death toll could have easily been in the thousands, as I discussed last month in my blog, "Big Wind in the Windy City".

The severe storm action finally quieted down yesterday in Kansas and the Plains; only 11 reports of tornadoes were received, compared to 93 on Saturday and 33 on Friday. The severe weather action should stay at a slow simmer through Wednesday over the Plains; the Storm Prediction Center (SPC) has portions of the region under its "Slight Risk" area for severe weather through Wednesday. Flooding is a major concern now; most of eastern Kansas, plus large portions of Oklahoma, Texas, Missouri, Iowa, Nebraska, and South Dakota are under flood warnings. More heavy thunderstorm rains during the week are expected to add to the problem.

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.


Wunderblogger Mike Theiss was out chasing the weekend storms; be sure to tune into his blog over the next few days to read his chase accounts.


Figure 1. Visible satellite image of the May 7, 2007 coastal storm.

Coastal Carolina storm
A powerful non-tropical low pressure system formed off the coast of North Carolina last night, and is bringing tropical storm-force winds as high as 55 mph to the waters offshore the Carolina coast, according to the latest QuikSCAT satellite wind estimates. The North Carolina Diamond Shoals buoy had 17 foot seas and sustained winds of 43 mph at 9am EDT this morning, and buoy 41001 about 175 miles east of Cape Hatteras recorded sustained winds of 62 mph gusting to 80 mph at 1am this morning. Seas were 41 feet at this buoy this morning! The strong winds will bring 10-20 foot seas and significant beach erosion to the shores of North Carolina, South Carolina, and northeast Florida through Wednesday. A 3-5 foot storm surge is expected along portions of the North Carolina coast through Tuesday morning. The latest set of computer model runs have the storm drifting slowly southwest, and bring it ashore between the South Carolina and northern Florida coast on Wednesday. The storm will start to develop thunderstorm activity and a warm core, but will probably not have time to become fully subtropical and become Subtropical Storm Andrea. However, the storm is only expected to weaken slowly, and will have an impact similar to a tropical storm in regards to offshore winds and coastal flooding today and Tuesday. If the storm does indeed make landfall on Wednesday as expected, it will most likely be of tropical depression strength, with top sustained winds around 30-35 mph. Heavy rains of 1-3 inches can be expected to the north of where the center makes landfall, but rains will not be as significant as what a tropical storm would bring.

I'll have an update on this storm Tuesday morning.
Jeff Masters

Raging Waters - Mill Creek1 (Cptkirk)
Same location - evenig shots!
Raging Waters - Mill Creek1
()
Storm Cloud Formation (FT2)
Detail of Turbulance Under the Trough on 05/06/2007 in SE Iowa.
Storm Cloud Formation

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

Sign In or Register Sign In or Register

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: 75 - 25

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

75. thelmores
5:02 PM GMT on May 07, 2007
The Navy is just Lazy this early in the year! :)
Member Since: September 8, 2005 Posts: 0 Comments: 3830
74. Patrap
12:00 PM CDT on May 07, 2007
No invest here..Link
Member Since: July 3, 2005 Posts: 433 Comments: 132802
73. seminolesfan
5:00 PM GMT on May 07, 2007
With convection firing to the west, the low center would be moved west as well.
Member Since: June 14, 2006 Posts: 0 Comments: 2108
72. seminolesfan
4:50 PM GMT on May 07, 2007
More convection to the west of the coc today than yesterday. Its def. becoming less frontal, where the convection tends to be more east.

Link
Member Since: June 14, 2006 Posts: 0 Comments: 2108
71. thelmores
4:56 PM GMT on May 07, 2007
anybody else see a westward jog in 90L???

could be a wobble... but it is WEST!!!

WEST I SAY! :D
Member Since: September 8, 2005 Posts: 0 Comments: 3830
70. Tazmanian
9:58 AM PDT on May 07, 2007
Test Floater - Subtropical System

lol
Member Since: Posts: Comments:
69. lightning10
4:53 PM GMT on May 07, 2007
Today not expecting any record breaking heat but highs will still be in the low to mid 90's in valley and foothill areas. Some breezes in the passes and canyons 15-25 MPH combined with Humidity of less then 25% will and the DRYEST WINTER ON RECORD will make for an interesting day fire wise.
Member Since: Posts: Comments:
67. Thundercloud01221991
4:53 PM GMT on May 07, 2007
Thanks

http://www.ssd.noaa.gov/goes/east/nwatl/loop-vis.html

look here and see new convection near the center this could be trying to develop a CDO
Member Since: August 1, 2006 Posts: 28 Comments: 3716
66. weatherboykris
4:52 PM GMT on May 07, 2007
It is the satellite estimate of the storm's stregnth,according to the Dvorak system.It means 40mph.
Member Since: Posts: Comments:
65. Thundercloud01221991
4:49 PM GMT on May 07, 2007
What does 2.5 mean
Member Since: August 1, 2006 Posts: 28 Comments: 3716
63. weathermanwannabe
12:39 PM EDT on May 07, 2007
Ideally, I hope the system can move down South to Florida as far as possible to bring some releif to the Lake Okechobee region; makes for an interesting dichotomy for Florida at this time..........While we desperately need the rain, can we afford more beach erosion?....Tough call but given the current predictions for the tropical season, I would take the rain now as we will probably get the erosion anyway later on down the road...
Member Since: Posts: Comments:
62. IKE
11:47 AM CDT on May 07, 2007
Moving SW...or it has in the last 6 hours.
Member Since: Posts: Comments:
61. IKE
11:43 AM CDT on May 07, 2007
Latest GFS has it coming in across NE Florida in a weakened state...Link
Member Since: Posts: Comments:
60. weatherboykris
4:43 PM GMT on May 07, 2007
ST 2.5 is the T number.
Member Since: Posts: Comments:
59. GainesvilleGator
4:25 PM GMT on May 07, 2007
I hope this low pressure system can make it all the way to the FL/GA border & put out those fires! The smoke got cleared out yesterday with that cold front. Today is the first time in a while in which we had blue skys.
Member Since: Posts: Comments:
58. ricderr
4:42 PM GMT on May 07, 2007
all i got to say......is.....if there's rain..come on down!!!!!
Member Since: Posts: Comments:
57. weatherboykris
4:41 PM GMT on May 07, 2007
90L has formed!
Member Since: Posts: Comments:
56. thelmores
4:35 PM GMT on May 07, 2007



WE HAVE RAIN ONSHORE!!!!

well, a little rain! LOL
Member Since: September 8, 2005 Posts: 0 Comments: 3830
55. thelmores
4:30 PM GMT on May 07, 2007
hey, i been practicing for months just to draw that semi-circle! LOL
Member Since: September 8, 2005 Posts: 0 Comments: 3830
54. thelmores
4:24 PM GMT on May 07, 2007
"Posted By: Jedkins
And no, the Carolinas don't need the rain that much"


excuse me, but YES WE NEED RAIN!!!!
Member Since: September 8, 2005 Posts: 0 Comments: 3830
52. fredwx
12:25 PM EDT on May 07, 2007
The Coastal low is a cold-core system - look at the well developed 500mb cut-off low.

Tuesday Evening 500 mb Forecast
Member Since: Posts: Comments:
50. thelmores
4:23 PM GMT on May 07, 2007


looks like we finally have some thunderstorms firing on the west side......

GO WEST!! GO WEST!!
Member Since: September 8, 2005 Posts: 0 Comments: 3830
48. rxse7en
12:17 PM EDT on May 07, 2007
"I'll catch this bird for you, but it ain't gonna be easy."
Member Since: Posts: Comments:
47. Jedkins
4:18 PM GMT on May 07, 2007
Oh and there is some convective activity on the west side of the center, but its not deep moit tropical convection found in warm core yet, this thing is over too cool of water at this time to begin transition just yet.

Its chances to do so will not apply till tommorrow folks please don't overhype, be civilized.
46. Jedkins
4:17 PM GMT on May 07, 2007
And also, its not heading wsw, use your eyes, its moving south-southwest, as it has since last night.
45. V26R
4:17 PM GMT on May 07, 2007
Gotta get back to work, Talk to you later CB

Mike
Member Since: Posts: Comments:
44. Jedkins
4:08 PM GMT on May 07, 2007
And no, the Carolinas don't need the rain that much, Florida does, Lake Okee is at record low leves, heavy storms last 2 days has brought it back up just a bit, but we need alot more, yes the rain season is almost here, but its still about 3 weeks away on average, and with the strong Florida sun, thats plenty time to dry things up much further.


43. fredwx
12:17 PM EDT on May 07, 2007
NWS High Seas Forecast has a warning for Hurricane Force Winds:

NORTH ATLANTIC NORTH OF 31N TO 67N AND WEST OF 35W.
SYNOPSIS VALID 1200 UTC MAY 07.
24 HOUR FORECAST VALID 1200 UTC MAY 08.
48 HOUR FORECAST VALID 1200 UTC MAY 09.
.WARNINGS.

HURRICANE FORCE WIND WARNING
.LOW 32N 73W 998 MB MOVING SW 10 KT. OVER FORECAST
WATERS...WINDS 55 TO 70 KT SEAS 26 TO 39 FT BETWEEN 60 NM AND
180 NM N SEMICIRCLE. ELSEWHERE WINDS 40 TO 55 KT SEAS 18 TO 28
FT WITHIN 300 NM N SEMICIRCLE. WINDS 25 TO 40 KT SEAS 12 TO 24
FT ELSEWHERE FROM 31N TO 39N W OF 62W.
.24 HOUR FORECAST LOW MOVED S OF AREA NEAR 30N 77W 1002 MB.
FORECAST WINDS 40 TO 50 KT SEAS 16 TO 28 FT WITHIN 240 NM N
QUADRANT OVER FORECAST WATERS. ELSEWHERE FORECAST WINDS 25 TO 40
KT SEAS 12 TO 22 FT FROM 31N TO 38N W OF 68W.
.48 HOUR FORECAST LOW 31N 79W 1005 MB. FORECAST WINDS 25 TO 40
KT SEAS 11 TO 18 FT FROM 31N TO 34N W OF 71W.
Member Since: Posts: Comments:
42. V26R
4:14 PM GMT on May 07, 2007
Closest Bouy at Frying Pan Sholes showing
about 68 degs. Theres another one that I think could be closer to the Center but its OOS

Link
Member Since: Posts: Comments:
40. V26R
4:08 PM GMT on May 07, 2007
LilMax did you getthe Link for the Lightning Tracking site I posted for you last night?
Member Since: Posts: Comments:
39. lilmax
4:04 PM GMT on May 07, 2007
Thanks Dr. M.
Member Since: Posts: Comments:
38. weathermanwannabe
12:02 PM EDT on May 07, 2007
Hey all......We need a rainmaker for the SE so I hope it lingers around and sqeezes out the juice...........
Member Since: Posts: Comments:
37. V26R
4:06 PM GMT on May 07, 2007
Whats Up CB? How Ya Been?
Member Since: Posts: Comments:
35. V26R
4:02 PM GMT on May 07, 2007
Aren't Rouge Waves part of the red Menace?
Member Since: Posts: Comments:
34. melwerle
3:58 PM GMT on May 07, 2007
Nap time for me...catch y'all later!
Member Since: Posts: Comments:
33. Parkay
3:58 PM GMT on May 07, 2007
I captured my own loop of the storm cluster spinning up and spreading out. Its not the same zoom in as Dr. Master's, but it gives you an idea of the scale of the system.

Its a capture of all of the n0r reflectivity images on May 5 as they came in over my NOAAPORT feed.

http://weather.psychoses.org/ddc-n0r-may5-radloop.gif
Member Since: Posts: Comments:
32. StormJunkie
3:57 PM GMT on May 07, 2007
Thanks mel :~)

Maybe later tonight...Maybe. You will know for sure what it is going to do when it does it though...lol

Morning GS...lmao...
Member Since: Posts: Comments:
30. StormJunkie
3:54 PM GMT on May 07, 2007
lol SS.

Next GFS run should be coming out soon. Other models to follow between one and two. Someone wundermail me with anything interesting the next GFS says. For some reason, can't view the NWS model page from work, can't use the SSD page either.

Thanks, back to work!

Quick Links-Easily find model pages, imagery, marine data, wind data, and much more.
Member Since: Posts: Comments:
29. melwerle
3:54 PM GMT on May 07, 2007
yeah - it was pretty crazy. Kid had a BLAST - flipped the boat a couple of times but she was having a great time. Won't be doing THAT again. So when will they have a better grip on what this thing is or isn't? Later today? Tonight? Hey - great page btw SJ - you have everything on there. wooo hoooo!
Member Since: Posts: Comments:
28. SavannahStorm
3:52 PM GMT on May 07, 2007
Beware of the rouge waves- they might bring a blush to your cheeks.
Member Since: September 22, 2005 Posts: 18 Comments: 2344
27. StormJunkie
3:50 PM GMT on May 07, 2007
Mel, maybe in rain bands, but the low should start weekening if the models are correct. The worst winds should remain off shore, but as the low approaches the coast, could see some 30+mph sustained winds.

Can't believe you went sailing when we had those winds. That was a odd event. Windy as hell when that system passed through.
Member Since: Posts: Comments:
25. melwerle
3:46 PM GMT on May 07, 2007
Hey SJ - yep - it's breezy but not that bad. It was worse a couple of weekends ago - gusts at 45. I actually went SAILING in that nonsense. My daughter is bugging me to go out this week in this but I think I will play it safe. Should the winds be getting stronger throughout the week?
Member Since: Posts: Comments:

Viewing: 75 - 25

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

Top of Page

About

Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

Local Weather

Scattered Clouds
83 °F
Scattered Clouds

JeffMasters's Recent Photos

Dunham Lake Sunset
Carrot Nose in Danger
Deep Snow in Brookline, MA
Sunset at Fort DeSoto