

863 

WWUS20 KWNS 071959

SEL6

SPC WW 071959

NEZ000-SDZ000-080400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 736

NWS STORM PREDICTION CENTER NORMAN OK

300 PM CDT SUN AUG 7 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN AND CENTRAL NEBRASKA

       SOUTHWEST AND SOUTH CENTRAL SOUTH DAKOTA



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 300 PM UNTIL

1100 PM 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 5 MILES NORTHWEST OF

PHILIP SOUTH DAKOTA TO 45 MILES EAST SOUTHEAST OF NORTH PLATTE

NEBRASKA.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 734...WW 735...



DISCUSSION...THROUGH LATE AFTN...TSTMS ARE EXPECTED TO FORM BOTH

ALONG THE ERN/SRN SLOPES OF THE BLACK HILLS IN SWRN SD AND ALONG A

LEE TROUGH EXTENDING SWD INTO WRN NEB.  ACTIVITY WILL BE AIDED BY A

WEAK MID-LEVEL WAVE MIGRATING EWD FROM WY THROUGH THIS EVENING.

INITIALLY...SUPERCELLS WILL BE POSSIBLE GIVEN 40-45 KTS OF WLY

MID-LEVEL FLOW ATOP MOIST ESELY BOUNDARY LAYER FLOW.  LARGE HAIL

WILL BE LIKELY WITH INITIAL STORMS.  LATER THIS EVENING...ACTIVITY

SHOULD CONGEAL INTO ONE OR MORE TSTM CLUSTERS INCLUDING BOWING

STRUCTURES CONTAINING CORRIDORS OF HIGH WINDS.  STORMS SHOULD REACH

CNTRL NEB MID-LATE EVENING.



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 27040.





...RACY

