Saturday, May 10, 2008

Rare PDS watch to the west


URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 296
NWS STORM PREDICTION CENTER NORMAN OK
335 PM CDT SAT MAY 10 2008

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

SOUTHERN ARKANSAS
NORTHWEST MISSISSIPPI

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 335 PM UNTIL
1000 PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 2.5 INCHES IN DIAMETER...
THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE
POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 65 MILES NORTH NORTHWEST OF
TEXARKANA ARKANSAS TO 35 MILES NORTH OF GREENWOOD MISSISSIPPI.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 292
. WATCH NUMBER 292 WILL NOT BE IN EFFECT AFTER
335 PM CDT. CONTINUE...WW 293...WW 294...WW 295...

DISCUSSION...POTENTIALLY VOLATILE SITUATION MAY BE UNFOLDING ACROSS
PORTIONS OF SOUTHWEST AND SOUTHERN AR...EWD TO NWRN/CNTRL MS THROUGH
THIS EVENING AS LARGE DEEP-LAYER CYCLONE CONTINUES TO INTENSIFY
ACROSS KS/MO AND ASCENT STRENGTHENS ACROSS VERY UNSTABLE AIR MASS.
WARM FRONT NOW BISECTING AR NW-SE HAS BEEN REINFORCED BY DAYLONG
STRONG TO SEVERE ELEVATED CONVECTION ACROSS THE OZARK PLATEAU. AS
STRONGER FORCING NOW EMERGES WITH THE ADVANCING UPPER
TROUGH...RESIDUAL WEAK INHIBITION SHOULD BE REMOVED AND ALLOW FOR
SURFACE-BASED STORM DEVELOPMENT. STORMS/SUPERCELLS DEVELOPING IN
UNPERTURBED AIR MASS ACROSS ERN/SERN OK WILL ENCOUNTER MOIST LOW
LEVEL ELY/SELY FLOW NEAR THE WARM FRONT/OUTFLOW BOUNDARY ACROSS AR
SHORTLY. LOW LEVEL SHEAR ALONG THIS BOUNDARY...AND ACROSS THE REST
OF THE WARM SECTOR...WILL SUPPORT LONG-LIVED UPDRAFT ROTATION. A
CORRIDOR OF GREATER POTENTIAL FOR STRONG TO INTENSE LOW LEVEL STORMS
ROTATION MAY EVOLVE THROUGH THE EVENING HOURS WITH THE THREAT OF ONE
OR TWO LONGER-LIVED STRONG TORNADOES WITHIN THE WATCH AREA.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 26030.


...CARBIN

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