

575 

WWUS20 KWNS 051149

SEL7

SPC WW 051149

IAZ000-MNZ000-SDZ000-051800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 247

NWS STORM PREDICTION CENTER NORMAN OK

650 AM CDT SAT MAY 5 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWEST IOWA

       SOUTHWEST MINNESOTA

       SOUTHEAST SOUTH DAKOTA



EFFECTIVE THIS SATURDAY MORNING AND AFTERNOON FROM 650 AM UNTIL

100 PM 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 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES WEST

NORTHWEST OF CHAMBERLAIN SOUTH DAKOTA TO 25 MILES SOUTH SOUTHEAST

OF WORTHINGTON MINNESOTA.  FOR A COMPLETE DEPICTION OF THE WATCH

SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 245...WW 246...



DISCUSSION...ELEVATED TSTMS...INCLUDING SUSTAINED STORMS AND

POSSIBLY A COUPLE SUPERCELLS...EXPECTED TO MOVE/DEVELOP E TO ESE

ACROSS WW AREA THROUGH LATER THIS MORNING AS LOW LVL WAA/MOISTURE

TRANSPORT INCREASE AHEAD OF WEAK DISTURBANCES PRECEDING MAIN WRN

U.S. UPR TROUGH.  MAIN SVR THREAT SHOULD BE LARGE HAIL GIVEN SIZABLE

CLOUD LAYER SHEAR AND QUALITY OF ELEVATED MOISTURE INFLOW.



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

