

000 

WWUS20 KWNS 290252

SEL9

SPC WW 290252

MNZ000-NDZ000-290900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 769

NWS STORM PREDICTION CENTER NORMAN OK

955 PM CDT MON JUL 28 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN MINNESOTA

       EASTERN NORTH DAKOTA



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 955 PM UNTIL

400 AM 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 55

STATUTE MILES EAST AND WEST OF A LINE FROM 65 MILES NORTH

NORTHEAST OF DEVILS LAKE NORTH DAKOTA TO 65 MILES SOUTH OF FARGO

NORTH DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 767...WW 768...



DISCUSSION...THUNDERSTORMS ARE INCREASING OVER CENTRAL ND IN REGION

OF LOW LEVEL WARM ADVECTION...AHEAD OF APPROACHING UPPER TROUGH.

RATHER STEEP MID LEVEL LAPSE RATES AND SUFFICIENT INSTABILITY WILL

MAINTAIN STORMS INTO THE OVERNIGHT HOURS...WHILE 40+ KNOT EFFECTIVE

SHEAR VALUES PROMOTE SUPERCELL STORM STRUCTURES.  LARGE HAIL AND

DAMAGING WINDS ARE EXPECTED TO BE THE MAIN THREATS.



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 27030.





...HART

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