

000 

WWUS20 KWNS 170406

SEL3

SPC WW 170406

NDZ000-171100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 403

NWS STORM PREDICTION CENTER NORMAN OK

1105 PM CDT SAT JUN 16 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MUCH OF NORTH DAKOTA



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 1105 PM

UNTIL 600 AM CDT.



HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 60

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 145

STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES NORTH

NORTHEAST OF GARRISON NORTH DAKOTA TO 55 MILES SOUTH OF BISMARCK

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 401...WW 402...



DISCUSSION...ELEVATED THUNDERSTORMS WILL CONTINUE TO INCREASE IN

COVERAGE/INTENSITY AND SPREAD EWD/NEWD THROUGH THE EARLY MORNING

HOURS IN ASSOCIATION WITH A DEVELOPING 40 KT LLJ.  A FEED OF MODEST

INSTABILITY FROM SD WILL FUEL THE CONVECTION...WHILE EFFECTIVE SHEAR

IN EXCESS OF 50 KT COULD SUPPORT A FEW ELEVATED SUPERCELLS...WHICH

WOULD LOCALLY ENHANCE THE LARGE HAIL THREAT.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 50

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 26025.





...THOMPSON

