SEL7
   
   URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 127
   NWS STORM PREDICTION CENTER NORMAN OK
   825 PM CDT TUE APR 5 2005
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
   
          SOUTHWEST ARKANSAS
          NORTHWEST LOUISIANA
          EXTREME SOUTHEAST OKLAHOMA
          CENTRAL AND EAST TEXAS
   
   EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 825 PM
   UNTIL 400 AM CDT.
   
   HAIL TO 2 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 75
   STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH
   NORTHEAST OF TEXARKANA ARKANSAS TO 45 MILES EAST OF SAN ANTONIO
   TEXAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
   WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).
   
   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...THIS SEVERE THUNDERSTORM WATCH REPLACES
   TORNADO WATCH NUMBER 125. WATCH NUMBER 125 WILL NOT BE IN EFFECT
   AFTER 825 PM CDT. CONTINUE...WW 123...WW 126...
   
   DISCUSSION...BROKEN LINE OF SEVERE STORMS WILL CONTINUE TO MOVE EWD
   OFF DRYLINE IN CENTRAL AND NE TX.  LOW-LEVEL LIFT ALONG THE DRYLINE
   AND STORM SCALE OUTFLOWS...ALONG WITH A MID LEVEL SPEED MAX ROTATING
   ESEWD TOWARD CENTRAL TX...WILL HELP MAINTAIN STORMS INTO TONIGHT. 
   MODERATE INSTABILITY /MLCAPE NEAR 1500 J/KG/ AND RELATIVELY STRONG
   DEEP LAYER SHEAR WILL SUPPORT A CONTINUED THREAT OF SUPERCELLS AND
   EMBEDDED BOW ECHOES CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING
   WINDS. WHILE AN ISOLATED TORNADO CANNOT BE RULED OUT GIVEN THE
   MODEST LOW-LEVEL SHEAR E OF THE ONGOING STORMS FROM SW AR INTO NE
   TX...THE TENDENCY FOR STORMS TO MERGE INTO LARGER LINE SEGMENTS AND
   GRADUALLY WEAKENING INSTABILITY SUGGESTS THAT ANY TORNADO THREAT
   WILL BE MARGINAL.
   
   AVIATION...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 500. MEAN STORM
   MOTION VECTOR 27025.
   
   
   ...THOMPSON