

128 

WWUS20 KWNS 130139

SEL3

SPC WW 130139

NDZ000-130800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 463

NWS STORM PREDICTION CENTER NORMAN OK

840 PM CDT MON JUL 12 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN NORTH DAKOTA



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 840 PM UNTIL

300 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 80

STATUTE MILES EAST AND WEST OF A LINE FROM 70 MILES NORTHWEST OF

MINOT NORTH DAKOTA TO 5 MILES WEST OF LEMMON SOUTH 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 459...WW 460...WW

461...WW 462...



DISCUSSION...ISOLATED THUNDERSTORMS CONTINUE ALONG A PRE-FRONTAL

CONFLUENCE AXIS ACROSS WRN ND...IN AN ENVIRONMENT OF WEAK-MODERATE

INSTABILITY AND FAVORABLE VERTICAL SHEAR FOR SUPERCELLS.  THIS

CONVECTION WILL PERSIST FOR ANOTHER FEW HOURS...AND ADDITIONAL

STORMS SHOULD MOVE INTO WRN ND FROM ERN MT IN ADVANCE OF A MIDLEVEL

SHORTWAVE TROUGH.  WHILE A TORNADO CANNOT BE RULED OUT IN THE NEXT

1-2 HOURS...THE PRIMARY SEVERE THREATS SHOULD BE LARGE HAIL AND

DAMAGING WINDS INTO THE OVERNIGHT HOURS.



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 27020.





...THOMPSON

