

000 

WWUS20 KWNS 032100

SEL9

SPC WW 032100

IAZ000-MNZ000-NEZ000-SDZ000-040500-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 479

NWS STORM PREDICTION CENTER NORMAN OK

400 PM CDT TUE JUL 3 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       NORTHWEST AND NORTH CENTRAL IOWA

       SOUTHWEST MINNESOTA

       NORTHEAST NEBRASKA

       SOUTHEAST SOUTH DAKOTA



EFFECTIVE THIS TUESDAY AFTERNOON FROM 400 PM UNTIL MIDNIGHT CDT.



TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 45 MILES WEST OF NORFOLK

NEBRASKA TO 20 MILES NORTHEAST OF MASON CITY IOWA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU9).



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 477...WW 478...



DISCUSSION...TSTMS/POSSIBLE SUPERCELLS EXPECTED TO DEVELOP IN THE

NEXT 1-2 HRS AS HEATING CONTINUES INVOF SE-MOVING FRONT.  RICH

MOISTURE INFLOW AND STEEP MID LEVEL LAPSE RATES ARE CONTRIBUTING TO

SUBSTANTIAL CAPE AND POTENTIALLY LOW CLOUD BASES.  THIS MAY SUPPORT

A THREAT FOR A COUPLE TORNADOES...DESPITE MODEST LOW LVL

SHEAR...BEFORE ACTIVITY EVOLVES INTO A CLUSTER WITH A CONTINUING

THREAT FOR LARGE HAIL/WIND.



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

SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

550. MEAN STORM MOTION VECTOR 29025.





...CORFIDI

