

151 

WWUS20 KWNS 180200

SEL6

SPC WW 180200

IAZ000-MNZ000-NEZ000-SDZ000-WIZ000-180800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 486

NWS STORM PREDICTION CENTER NORMAN OK

855 PM CDT SAT JUL 17 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN IOWA

       SOUTHERN MINNESOTA

       FAR NORTHEASTERN NEBRASKA

       SOUTHEASTERN SOUTH DAKOTA

       WESTERN WISCONSIN



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 855 PM

UNTIL 300 AM CDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 75

STATUTE MILES EITHER SIDE OF A LINE FROM 25 MILES SOUTHWEST OF

SIOUX FALLS SOUTH DAKOTA TO 30 MILES NORTH OF CAMP DOUGLAS

WISCONSIN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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 483...WW 484...WW 485...



DISCUSSION...BOW ECHO HAS DEVELOPED NEAR MSP AND IS EXPECTED TO

TRACK RAPIDLY ESEWD INTO WRN WI THIS EVENING. ANOTHER CLUSTER OF

STORMS IN SWRN MN ARE LOCATED NEAR INTERSECTION OF STRENGTHENING LOW

LEVEL JET AND STRONG FEED OF INSTABILITY. THIS CLUSTER MAY ALSO

DEVELOP INTO A BOW ECHO AND MOVE ESEWD OVERNIGHT. WIND DAMAGE SHOULD

BE THE PRIMARY THREAT WITH THESE FEATURES...WITH AN ISOLATED BRIEF

TORNADO POSSIBLE WITHIN THE BOW HEADS. ALSO...AS THE LOW LEVEL JET

STRENGTHENS OVERNIGHT...OTHER STORMS ARE ALSO LIKELY TO DEVELOP WITH

A THREAT FOR LARGE HAIL.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 29035.





...IMY

