

622 

WWUS20 KWNS 052217

SEL2

SPC WW 052217

MTZ000-NEZ000-SDZ000-WYZ000-060600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 472

NWS STORM PREDICTION CENTER NORMAN OK

410 PM MDT THU JUL 5 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST MONTANA

       NORTHWEST NEBRASKA

       WESTERN AND WEST CENTRAL SOUTH DAKOTA

       EASTERN WYOMING



EFFECTIVE THIS THURSDAY AFTERNOON FROM 410 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 85

STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES SOUTHWEST OF

TORRINGTON WYOMING TO 25 MILES NORTH NORTHWEST OF BUFFALO SOUTH

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

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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 469...WW 470...WW 471...



DISCUSSION...TSTMS EXPECTED TO INCREASE IN COVERAGE AND POSSIBLY

STRENGTH THROUGH LATE TNGT IN ZONE OF MOISTENING...SSELY LOW LVL

FLOW AND INCREASING UPR LVL DIVERGENCE DOWNSTREAM FROM UPR IMPULSE

MOVING NNE INTO THE NRN RCKYS.  OTHERS STORMS EXPECTED TO CONTINUE

FORMING FARTHER E NEAR WARM FRONT OVER NRN NEB/WRN SD...AND OVER THE

BLACK HILLS.  WHILE THE INITIAL SVR THREATS SHOULD BE SVR HAIL/DMGG

WIND...BACKED AND INCREASINGLY MOIST LOW LVL FLOW MAY SUPPORT AN

INCREASING TORNADO RISK THIS EVE...MAINLY NEAR WARM FRONT AND THE

BLACK HILLS.  PARTS OF NE WY/WRN SD AND PERHAPS SE MT MAY REQUIRE

UPGRADE TO TORNADO TOWARD THAT TIME.



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 550. MEAN STORM

MOTION VECTOR 21030.





...CORFIDI

