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594 

WWUS20 KWNS 201939

SEL3

SPC WW 201939

NDZ000-210200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 503

NWS STORM PREDICTION CENTER NORMAN OK

240 PM CDT TUE JUL 20 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN NORTH DAKOTA



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 240 PM UNTIL

900 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 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES WEST OF

WILLISTON NORTH DAKOTA TO 80 MILES EAST OF MINOT NORTH DAKOTA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU3).



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 502...



DISCUSSION...THUNDERSTORMS HAVE DEVELOPED AHEAD OF SHORTWAVE TROUGH

MOVING THROUGH EASTERN MT.  THESE STORMS ARE IN AN ENVIRONMENT OF

COLD MID LEVEL TEMPERATURES AND STEEP LAPSE RATES...FAVORABLE FOR

LARGE HAIL AND LOCALLY DAMAGING WINDS.  ACTIVITY IS LIKELY TO SPREAD

EASTWARD ACROSS WATCH AREA THROUGH THE EARLY 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 450. MEAN STORM

MOTION VECTOR 27030.





...HART

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