

707 

WWUS20 KWNS 200029

SEL5

SPC WW 200029

NDZ000-SDZ000-200600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 605

NWS STORM PREDICTION CENTER NORMAN OK

630 PM MDT SUN JUL 19 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN NORTH DAKOTA

       WESTERN SOUTH DAKOTA



EFFECTIVE THIS SUNDAY NIGHT FROM 630 PM UNTIL MIDNIGHT MDT.



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 EAST AND WEST OF A LINE FROM 55 MILES NORTHWEST OF

MINOT NORTH DAKOTA TO 120 MILES SOUTH OF LEMMON SOUTH DAKOTA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU5).



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 603...WW 604...



DISCUSSION...TSTMS NOW FORMING IN WAA AREA OVER WRN ND/SD EXPECTED

TO INCREASE THROUGH EARLY EVE AS HEIGHT FALLS GRADUALLY INCREASE

ACROSS REGION WITH GLANCING ABROACH OF SK UPR TROUGH.  NARROW

CORRIDOR OF SFC-BASED INSTABILITY JUXTAPOSED WITH SUFFICIENT DEEP

SHEAR FOR SUSTAINED UPDRAFTS/SUPERCELLS SUGGESTS POTENTIAL FOR LARGE

HAIL AND LOCALLY DMGG WIND AS ACTIVITY POSSIBLY MERGES INTO ONE OR

TWO SMALL CLUSTERS.



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 28025.





...CORFIDI

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