279 

WWUS20 KWNS 092010

SEL7  

SPC WW 092010

ARZ000-ILZ000-KYZ000-MOZ000-TNZ000-100300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 677

NWS STORM PREDICTION CENTER NORMAN OK

210 PM CST SUN DEC 9 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF 



       CENTRAL AND NORTHEAST ARKANSAS

       SOUTHERN ILLINOIS

       WESTERN KENTUCKY

       SOUTHEAST MISSOURI

       NORTHWEST TENNESSEE



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 210 PM UNTIL 900

PM CST.



TORNADOES...HAIL TO 2 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 EAST AND WEST OF A LINE FROM 30 MILES NORTHEAST OF CAPE

GIRARDEAU MISSOURI TO 25 MILES WEST OF PINE BLUFF ARKANSAS.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU7).



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.



DISCUSSION...THUNDERSTORMS ARE BEGINNING TO INTENSIFY OVER CENTRAL

AR ALONG/AHEAD OF COLD FRONT.  STORMS SHOULD INCREASE IN COVERAGE

THROUGH THE AFTERNOON ACROSS THE WATCH AREA AS LOW LEVEL WINDS

STRENGTHEN.  A FEW SEVERE STORMS CAPABLE OF DAMAGING WINDS AND HAIL

ARE EXPECTED.  ISOLATED SUPERCELLS ARE ALSO POSSIBLE WITH A RISK OF

A TORNADO OR TWO THROUGH THE EARLY EVENING.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

400. MEAN STORM MOTION VECTOR 25035.





...HART






697 

WWUS20 KWNS 092350

SEL8  

SPC WW 092350

ARZ000-LAZ000-MSZ000-TXZ000-100600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 678

NWS STORM PREDICTION CENTER NORMAN OK

550 PM CST SUN DEC 9 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 



       SOUTHERN ARKANSAS

       WESTERN AND NORTHERN LOUISIANA

       EXTREME WESTERN MISSISSIPPI

       SOUTHEAST TEXAS



EFFECTIVE THIS SUNDAY AFTERNOON FROM 550 PM UNTIL MIDNIGHT CST.



HAIL TO 1.5 INCHES 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 90

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH

NORTHWEST OF MONTICELLO ARKANSAS TO 45 MILES SOUTHEAST OF

HUNTSVILLE TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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 677...



DISCUSSION...SCATTERED TSTMS NEAR FRONT...AS WELL AS CLUSTERED

CONVECTION TO ITS E...SHOULD POSE RISK FOR SVR HAIL AND DAMAGING

GUSTS THROUGH EVENING.  MRGL SUPERCELL SCENARIO EXISTS FOR

DISCRETE/PREFRONTAL CONVECTION...WITH 45-55 KT EFFECTIVE SHEAR

MAGNITUDES BUT WEAK NEAR-SFC WINDS.  EFFECTIVELY SFC-BASED PARCELS

SHOULD PERSIST THROUGH ABOUT 06Z OVER MUCH OF AREA AS LONG AS

WARM/MOIST ADVECTION OFFSETS DIABATIC SFC COOLING.  TSTMS NEAR FRONT

SHOULD BE UNDERCUT QUICKLY...PER SPC MESOSCALE DISCUSSION 2141.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM

MOTION VECTOR 23035.





...EDWARDS