

204 

WWUS20 KWNS 012021

SEL8

SPC WW 012021

NEZ000-SDZ000-020400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 548

NWS STORM PREDICTION CENTER NORMAN OK

320 PM CDT WED AUG 1 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN NEBRASKA

       SOUTH-CENTRAL AND EASTERN SOUTH DAKOTA



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 320 PM UNTIL

1100 PM CDT.



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 25 MILES WEST

SOUTHWEST OF MULLEN NEBRASKA TO 60 MILES NORTH NORTHWEST OF HURON

SOUTH DAKOTA.  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 544...WW 546...WW 547...



DISCUSSION...STORMS WILL CONTINUE TO INCREASE IN BOTH INTENSITY AND

COVERAGE AHEAD AND ALONG A COLD FRONT AND LEE TROUGH DEVELOPING INTO

THE WATCH AREA. AIRMASS ACROSS SD AND NEB HAS BECOME MODERATELY TO

STRONGLY UNSTABLE WITH LATEST MLCAPE ESTIMATES BETWEEN 1500-2000 J

PER KG. CONVECTION WILL DEVELOP EAST AIDED BY LARGE SCALE ASCENT

ACCOMPANYING A SHORTWAVE TROUGH CROSSING THE NRN PLAINS THROUGH

TONIGHT. DEEP-LAYER SHEAR WILL BE SUFFICIENT FOR BOTH SUPERCELLS AND

LONGER-LIVED LINE SEGMENTS WITH ATTENDANT THREATS OF LARGE HAIL AND

HIGH WINDS.



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 550. MEAN STORM

MOTION VECTOR 27030.





...CARBIN

