

337 

WWUS20 KWNS 110028

SEL8

SPC WW 110028

NDZ000-110700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 738

NWS STORM PREDICTION CENTER NORMAN OK

730 PM CDT THU SEP 10 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL INTO NORTHEASTERN NORTH DAKOTA



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 730 PM

UNTIL 200 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 70

STATUTE MILES EAST AND WEST OF A LINE FROM 60 MILES SOUTH OF

BISMARCK NORTH DAKOTA TO 65 MILES NORTH NORTHEAST OF DEVILS LAKE

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

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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...VERY STRONG UPPER LEVEL SYSTEM DIGGING ACROSS THE NRN

HIGH PLAINS WILL FOCUS INCREASING THUNDERSTORMS OVER CENTRAL ND THIS

EVENING/OVERNIGHT.  00Z SOUNDINGS INDICATE STEEP MID LEVEL LAPSE

RATES WITH SUFFICIENT INFLUX OF LOW LEVEL MOISTURE TO SUSTAIN

MODERATE MUCAPE OVERNIGHT.  LOW LEVEL SHEAR REMAINS WEAK...HOWEVER

SUFFICIENT DEEP LAYER SHEAR WILL REMAIN IN PLACE FOR ORGANIZATION

INTO CLUSTERS/LINES AND PERHAPS A FEW SUPERCELLS.  LARGE HAIL AND

HEAVY RAIN WILL BE PRIMARY THREATS...ALTHOUGH ISOLATED DAMAGING

WINDS REMAIN POSSIBLE.



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 26020.





...EVANS

