

914 

WWUS20 KWNS 292026

SEL4

SPC WW 292026

MNZ000-NDZ000-SDZ000-300400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 234

NWS STORM PREDICTION CENTER NORMAN OK

325 PM CDT SAT MAY 29 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SMALL PART OF NORTHWEST MINNESOTA

       MUCH OF EASTERN NORTH DAKOTA

       MUCH OF CENTRAL AND PARTS OF EASTERN SOUTH DAKOTA



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 325 PM UNTIL

1100 PM CDT.



HAIL TO 2.5 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 80

STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES WEST

NORTHWEST OF HALLOCK MINNESOTA TO 55 MILES SOUTH SOUTHWEST OF

CHAMBERLAIN SOUTH DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH

SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 232...WW 233...



DISCUSSION...AIR MASS AHEAD OF N/S COLD FRONT HAS BECOME VERY

UNSTABLE WITH LITTLE REMAINING CINH. WITH MLCAPES AOA 2500 AND 30-40

KT OF DEEP LAYER SHEAR...STRONG/SEVERE THUNDERSTORMS EXPECTED TO

INITIATE VICINITY COLD FRONT AND THEN DEVELOP N AND E ON BOTH SIDES

OF FRONT THRU THE EVENING.  PRIMARY THREAT WILL BE LARGE HAIL AND

DAMAGING DOWNBURSTS WINDS GIVEN THE STEEP LAPSE RATES.



AVIATION...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 20025.





...HALES

