

374 

WWUS20 KWNS 082157

SEL6

SPC WW 082157

COZ000-KSZ000-NEZ000-090600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 746

NWS STORM PREDICTION CENTER NORMAN OK

355 PM MDT MON AUG 8 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST COLORADO

       NORTHWEST KANSAS

       WESTERN NEBRASKA



EFFECTIVE THIS MONDAY AFTERNOON FROM 355 PM UNTIL MIDNIGHT MDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75

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 30 MILES EAST

NORTHEAST OF CHADRON NEBRASKA TO 15 MILES SOUTH SOUTHEAST OF

GOODLAND KANSAS.  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.



DISCUSSION...TSTMS NOW FORMING IN WRN NEBRASKA EXPECTED TO INCREASE

IN COVERAGE AND STRENGTH THROUGH MID EVE AS SFC HEATING AND ASCENT

WITH UPR DISTURBANCE PASSING IMMEDIATELY TO THE N FURTHER

DESTABILIZE REGION.  LOW LVL CONVERGENCE WILL REMAIN WEAK.  BUT

EXPECTED SSE TO SWD STORM MOTION WILL ENHANCE STORM RELATIVE INFLOW.

 TOGETHER WITH SLIGHT UPSLOPE COMPONENT TO LOW LVL FLOW...INCREASING

LOW LVL MOISTURE WITH SWD EXTENT...AND THE PRESENCE OF AMPLE DEEP

SHEAR...THERE WILL EXIST A POSSIBILITY FOR SUPERCELLS WITH LARGE

HAIL AND LOCALLY DMGG WIND.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 34025.





...CORFIDI

