Southern US derecho - May 3

[CrazyC83]

Started a new thread, surprised there wasn't one. Finally able to get on after 3 days on the road (not in that area, fortunately).

[CrazyC83]

So far 1 person dead based on SPC reports. Surprised they never went high risk.

[CrazyC83]

MESOSCALE DISCUSSION 0691
NWS STORM PREDICTION CENTER NORMAN OK
0536 PM CDT SUN MAY 03 2009

AREAS AFFECTED...GA

CONCERNING...SEVERE THUNDERSTORM WATCH 234...235...

VALID 032236Z - 040000Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
234...235...CONTINUES.

DERECHO WAS BEGINNING TO DIMINISH...BUT LAST VESTIGES OF THE BOW
ECHO CONTINUE TO HAVE THE POTENTIAL FOR DMGG WINDS/ISOLD BRIEF
TORNADOES ACROSS ESPECIALLY CNTRL/NRN GA THROUGH 00Z AT LEAST.

STRONGEST TSTMS HAVE BEEN FAVORING A ZONE ACROSS CNTRL/NRN GA WHERE
AIR MASS HEATED THE MOST TODAY AMIDST COMPARATIVELY RICHER BOUNDARY
LAYER MOISTURE THAN FARTHER TO THE S. LINE IS MOVING ROUGHLY 260/40
AND SHOULD REACH THE ERN END OF WW 235 BY 00Z. BY THEN...BOUNDARY
LAYER SHOULD BEGIN TO STABILIZE AND BECOME MORE HOSTILE AT
SUPPORTING WIDESPREAD SVR WEATHER. THERE WILL BE SOME CONTINUING
THREAT OF DMGG WINDS INTO UPSTATE SC LATER THIS EVENING...GENERALLY
SINCE THE LINE OF STORMS WILL CONTINUE NEWD WITHIN A 60 KT MID-LVL
JET CORE. HOWEVER...IT IS NOT YET CLEAR ON WHETHER ANOTHER WW WILL
BE NEEDED.

MEANWHILE...THROUGH 00Z...THREAT FOR DMGG WINDS WILL ACCOMPANY THE
LINE. FFC VWP SAMPLED AROUND 200 M2/S2 0-1KM SRH JUST BEFORE THE
STORMS MOVED THROUGH THE RADAR SITE...AND EMBEDDED ROTATING
COMMA-HEAD FEATURES WILL KEEP THE THREAT FOR AN ISOLD BRIEF TORNADO
ALIVE AS WELL.

..RACY.. 05/03/2009


ATTN...WFO...CAE...GSP...FFC...TAE...BMX...

LAT...LON 31308548 32528471 34158481 34868432 34378338 33618214
32418241 31958336 31298421 31308548

[CrazyC83]

SEL6

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 236
NWS STORM PREDICTION CENTER NORMAN OK
730 PM EDT SUN MAY 3 2009

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

NORTHEAST GEORGIA
UPSTATE AND CENTRAL SOUTH CAROLINA

EFFECTIVE THIS SUNDAY NIGHT FROM 730 PM UNTIL MIDNIGHT EDT.

HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45
STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES WEST
NORTHWEST OF GREENVILLE SOUTH CAROLINA TO 70 MILES SOUTH
SOUTHEAST OF ANDERSON SOUTH CAROLINA. FOR A COMPLETE DEPICTION
OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS
WOU6).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 235...

DISCUSSION...BOWING LINE OF THUNDERSTORMS WILL CONTINUE TO POSE A
RISK OF LOCALLY DAMAGING WINDS FOR ANOTHER FEW HOURS AS THEY TRACK
INTO SC. SATELLITE...RADAR...AND LIGHTNING DATA SUGGEST LINE IS
DECREASING IN INTENSITY. HOWEVER...STRONG WINDS ALOFT AND MESOSCALE
ORGANIZATION OF SYSTEM WILL MAINTAIN RISK OF SEVERE WEATHER FOR
AWHILE LONGER.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. MEAN STORM MOTION
VECTOR 25035.


...HART