

000 

WWUS20 KWNS 190408

SEL1

SPC WW 190408

IAZ000-ILZ000-191100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 541

NWS STORM PREDICTION CENTER NORMAN OK

1105 PM CDT WED JUL 18 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EASTERN IOWA

       NORTHWEST ILLINOIS



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1105 PM

UNTIL 600 AM CDT.



HAIL TO 1 INCH 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 75

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH

NORTHEAST OF MOLINE ILLINOIS TO 35 MILES SOUTHEAST OF OTTUMWA

IOWA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 536...WW 537...WW

538...WW 539...WW 540...



DISCUSSION...SCTD ELEVATED STORMS MAY INCREASE IN NUMBER AND

MOVE/DEVELOP ESE THROUGH WW THROUGH EARLY THURSDAY AS WAA PATTERN

BECOMES REESTABLISHED ACROSS REGION IN WAKE OF NRN IL MCS.  DEGREE

OF UPSTREAM INSTABILITY AND HI PWS SUGGEST POTENTIAL FOR WET

MICROBURSTS AND MARGINALLY SVR HAIL.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION

VECTOR 30025.





...CORFIDI

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