

858 

WWUS20 KWNS 231601

SEL7

SPC WW 231601

MNZ000-NDZ000-232300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 497

NWS STORM PREDICTION CENTER NORMAN OK

1100 AM CDT TUE JUN 23 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN AND CENTRAL MINNESOTA

       EASTERN NORTH DAKOTA



EFFECTIVE THIS TUESDAY MORNING AND EVENING FROM 1100 AM UNTIL 600

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 30 MILES SOUTHWEST OF

BRAINERD MINNESOTA TO 30 MILES EAST NORTHEAST OF HALLOCK

MINNESOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 495...WW 496...



DISCUSSION...THUNDERSTORMS HAVE INCREASED ALONG AN ARCING OUTFLOW

BOUNDARY OVER WEST CENTRAL MN...WHILE ELEVATED STORMS CONTINUE TO

DEVELOP OVER NERN ND.  ACTIVITY APPEARS TO BE ASSOCIATED WITH

PRONOUNCED CYCLONIC SHEAR ASSOCIATED WITH A STRONG UPPER LEVEL JET

STREAK OVER NRN ND/SRN MANITOBA.  STEEP LAPSE RATES ABOVE THE PBL

WILL ENHANCE INSTABILITY DURING THE AFTERNOON HEATING CYCLE...AND

STRONG VERTICAL SHEAR WILL PROMOTE SEVERE STORM DEVELOPMENT THROUGH

HE AFTERNOON HOURS.



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 24030.





...EVANS

