

176 

WWUS20 KWNS 092251

SEL6

SPC WW 092251

IAZ000-NEZ000-SDZ000-100600-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 116

NWS STORM PREDICTION CENTER NORMAN OK

550 PM CDT SAT APR 9 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       WESTERN AND NORTHERN IOWA

       EASTERN NEBRASKA

       SOUTHEAST SOUTH DAKOTA



EFFECTIVE THIS SATURDAY AFTERNOON AND SUNDAY MORNING FROM 550 PM

UNTIL 100 AM CDT.



TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 95 STATUTE

MILES EAST AND WEST OF A LINE FROM 15 MILES SOUTH SOUTHWEST OF

LINCOLN NEBRASKA TO 25 MILES NORTH NORTHEAST OF SPENCER IOWA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU6).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 113...WW 114...WW 115...



DISCUSSION...TSTMS EXPECTED TO INCREASE OVER WW AREA THROUGH LATE

TONIGHT...WITH STRONG SUPERCELLS LIKELY AS CONVERGENCE/ASCENT AND

WIND FIELD FURTHER STRENGTHEN WITH APPROACH OF UPR AIR IMPULSE IN

FAST SWLY MID/UPR FLOW.  LOW-LVL HELICITY/UPLIFT SHOULD MAXIMIZE

NEAR AND ENE OF SFC LOW NOW NEAR KOFK...WITH THE LOW EXPECTED TO

REMAIN LARGELY STNRY THROUGH WW PERIOD.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

550. MEAN STORM MOTION VECTOR 24035.





...CORFIDI

