Another wild night in Tornado Alley
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
A big storm moved in on the 3rd. Wasn't as bad as it looked though.
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 — Blog Index
Ya know, to be honest, I think it's starting to look a lot like Alberto on the infrared.
In fact Miami reported 2.90 inches in a half hours time, pretty darn heavy.
Even bouy 41012 off the coast of northern FLA is registering 9 foot waves and 30 mph winds. Tropical or not, this is a strong storm.
-Dang- it's workday tomorrow. Guess I'll check up on it in the morning, to see what happened overnight!
The National Weather Service in San Angelo has issued a
* Tornado Warning for...
southern Irion County in southwest Texas...
* until 1245 am CDT
will give you much higher odds of a tornado manifesting, and on the other hand, a thunder
storm with no jet stream with in , lets say 500
miles will have a slim chance of producing a tornado! is this a fairly true statment?
Significant Wave Height (WVHT): 32.2 ft
Swell Height (SwH): 28.9 ft
Swell Period (SwP): 14.3 sec
Wind Wave Height (WWH): 13.5 ft
Wind Wave Period (WWP): 5.9 sec
Wave Steepness (STEEPNESS): AVERAGE
Average Wave Period (APD): 9.9 sec
Would u believe it's barely rained here? That blob just fizzled out as it crossed the Gulf Stream. However, I just heard a bit of thunder, so perhaps later this a. m. we will get a bit of rain. Meanwhile, the temperature has really dropped; it feels almost 10 degrees cooler out there than it did yesterday morning around this time . . .
I'm out for the day. Have a good one! (hope nobody gets hit with another tornado)
If the SE coastal low is to start becoming tropical or sub tropical it would likely not start happening until later tonight. That being said, it will have to get rid of that dry air if it has any shot. Will still be interesting to watch the evolution of this low either way though.
See y'all later
Quick Links
Link
ATTENTION REMAINS FOCUSED ON THE STRONG LOW PRES SYSTEM OFF THE
CAROLINA COASTLINE....ANALYZED 998 MB NEAR 33N72W. A BACK DOOR
COLD FRONT IS PROGRESSING SWD FROM THE LOW TO SOUTH FLORIDA.
SCATTERED SHOWERS WITH ISOLATED TSTMS WITH THE FRONT ARE MOSTLY
WITHIN 60NM EITHER SIDE OF THE FRONT...THOUGH MIAMI RADAR AND
LIGHTNING DATA DEPICT TSTMS ARE MORE SCATTERED BETWEEN SFL AND
THE SE BAHAMAS. THE MAIN IMPACT WITH THIS SYSTEM IS THE STRONG
WINDS AND LARGE SEAS AS A VERY TIGHT PRES GRADIENT HAS SET UP
BETWEEN THE LOW AND STRONG HIGH PRES OVER THE NORTHEAST STATES.
A STORM WARNING HAS BEEN POSTED FOR THE FAR NW PORTION OF THE
AREA AS DESCRIBED IN THE HIGH SEAS FORECAST. IN ADDITION TO THE
ALREADY VERY IMPRESSIVE FETCH...AS THE STORM MOVES SSW IT WILL
PROMOTE A CAPTURE FETCH TOWARDS THE BAHAMAS AND FLORIDA. THIS
WILL FURTHER ADD TO THE VERY LARGE N/NE SWELL EVENT. HIGH SURF
ADVISORIES HAVE THUS BEEN POSTED FOR MUCH OF THE SOUTHEAST
COAST...SEE STATEMENTS FROM LOCAL FORECAST OFFICES FOR MORE
DETAILS. FARTHER E...A 1008 MB LOW LOCATED NEAR 29N62W ATTACHED
IS EXPECTED TO DISSIPATE OVER THE NEXT 24 HOURS. SCATTERED TSTMS
ARE MAINLY E OF THE LOW N OF 26N BETWEEN 53W-61W.
7am central NHC discussion
Morning GR and Dnalia
We're finally getting the rain we so desperately needed. I just wish it didn't come with the weather we got last night. I was driving back up to Kendall from Homestead and saw lots of cloud to ground lightning (I'm sure this sparked off a few brush fires out in the Everglades), and the sky had a bit of a green tinge. by the time I got home the sky was black. Then I got the tornado warning for our area. It was a wild night.
Viewing: 801 - 851
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 — Blog Index