

735 

WWUS20 KWNS 020222

SEL4

SPC WW 020222

IAZ000-MNZ000-NEZ000-020600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 224

NWS STORM PREDICTION CENTER NORMAN OK

915 PM CDT TUE MAY 1 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN AND WESTERN IOWA

       A SMALL PART OF SOUTHERN MINNESOTA

       EASTERN NEBRASKA



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 915 PM

UNTIL 200 AM 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 65

STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES EAST

NORTHEAST OF SPENCER IOWA TO 35 MILES SOUTHWEST OF LINCOLN

NEBRASKA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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...THIS SEVERE THUNDERSTORM WATCH REPLACES

TORNADO WATCH NUMBER 220...SEVERE THUNDERSTORM WATCH NUMBER 221.

WATCH NUMBER 220 221 WILL NOT BE IN EFFECT AFTER 915 PM CDT.

CONTINUE...WW 222...WW 223...



DISCUSSION...SCTD TSTMS EXPECTED TO DEVELOP OVER ERN NEB IN ZONE OF

STRENGTHENING LOW LVL WAA/MOISTURE INFLOW E AND S OF PRE-COLD

FRONTAL CONFLUENCE AXIS.  FARTHER N...STORMS EXPECTED TO CONTINUE

FORMING ALONG CONSOLIDATING OUTFLOW LEFT BY EARLIER STORMS IN SRN

MN/SE SD.  STRENGTHENING/SLIGHTLY VEERING LLJ AND ARRIVAL OF RATHER

MOIST AIR /PW AOA 1 INCH/ FROM KS SUGGESTS POTENTIAL FOR FEW

SUPERCELLS WITH LARGE HAIL...LOCALLY DMGG WIND...AND POSSIBLY A

TORNADO.  ACTIVITY IN NRN IA MAY CONSOLIDATE INTO A LARGER SCALE BOW

AND CONTINUE E/ESE ACROSS NRN IA WITH SPORADIC DMGG

WIND...HAIL...AND PERHAPS A BRIEF TORNADO.



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 26030.





...CORFIDI

