

256 

WWUS20 KWNS 010152

SEL9

SPC WW 010152

MTZ000-NDZ000-010900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 819

NWS STORM PREDICTION CENTER NORMAN OK

855 PM CDT WED AUG 31 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       FAR EASTERN MONTANA

       WESTERN AND CENTRAL NORTH DAKOTA



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 855 PM

UNTIL 400 AM 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 80

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES NORTH

NORTHWEST OF GLENDIVE MONTANA TO 55 MILES EAST SOUTHEAST OF MINOT

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.



DISCUSSION...AIDED BY DPVA/INCREASING WARM ADVECTION...CLUSTERS OF

STORMS WILL CONTINUE TO STEADILY SPREAD EAST-NORTHEASTWARD THROUGH

THE EVENING FROM FAR EASTERN MT INTO WESTERN/CENTRAL ND...WITH SOME

ADDITIONAL UPSCALE GROWTH/ORGANIZATION POSSIBLE INTO AN MCS. A

RELATIVELY UNSTABLE/STRONGLY SHEARED ENVIRONMENT WILL SUPPORT A

SUSTAINED SEVERE THREAT WITH DAMAGING WINDS/SEVERE HAIL POSSIBLE.



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 500. MEAN STORM

MOTION VECTOR 23030.





...GUYER/THOMPSON

