Things starting to rev up, big derecho in central Texas:
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 85
NWS STORM PREDICTION CENTER NORMAN OK
240 PM CDT MON MAR 19 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
CENTRAL AND NORTH CENTRAL TEXAS
EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 240 PM UNTIL
1000 PM CDT.
TORNADOES...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 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 10 MILES EAST NORTHEAST OF
SHERMAN TEXAS TO 85 MILES SOUTH SOUTHWEST OF JUNCTION TEXAS. FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU5).
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...CONVECTION HAS SHOWN A TENDENCY TO INTENSIFY ALONG AN
OUTFLOW BOUNDARY THAT IS DRIFTING EWD ACROSS CENTRAL/N CENTRAL
TX...PARTIALLY AIDED BY THE GLANCING INFLUENCE OF AN EMBEDDED SPEED
MAX EJECTING NEWD OVER W TX. MODERATE-STRONG INSTABILITY IS PRESENT
E OF THE BOUNDARY...AND VERTICAL SHEAR IS FAVORABLE FOR SUPERCELLS
AS WELL AS BOWING SEGMENTS. AS A RESULT...THE RISK FOR LARGE HAIL
AND DAMAGING WINDS SHOULD INCREASE THIS AFTERNOON AND PERSIST INTO
THIS EVENING. ADDITIONALLY...ANY OF THE STORMS ROOTED ALONG THE
IMMEDIATE SURFACE BOUNDARY WILL HAVE THE POTENTIAL TO PRODUCE A FEW
TORNADOES.
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
550. MEAN STORM MOTION VECTOR 23045.