

129 

WWUS20 KWNS 121855

SEL8

SPC WW 121855

IAZ000-ILZ000-MNZ000-WIZ000-130200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 298

NWS STORM PREDICTION CENTER NORMAN OK

150 PM CDT WED JUN 12 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* TORNADO WATCH FOR PORTIONS OF

  NORTHEAST IOWA

  NORTHERN ILLINOIS

  EXTREME SOUTHEAST MINNESOTA

  SOUTHWEST WISCONSIN



* EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 150 PM

  UNTIL 900 PM CDT.



...THIS IS A PARTICULARLY DANGEROUS SITUATION...



* PRIMARY THREATS INCLUDE...

  SEVERAL INTENSE TORNADOES LIKELY

  SEVERAL SIGNIFICANT DAMAGING WIND GUSTS TO 80 MPH POSSIBLE

  SEVERAL VERY LARGE HAIL EVENTS TO 3 INCHES IN DIAMETER POSSIBLE



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE

MILES EITHER SIDE OF A LINE FROM 35 MILES WEST SOUTHWEST OF MASON

CITY IOWA TO 20 MILES EAST SOUTHEAST OF ROCKFORD ILLINOIS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU8).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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.



&&



DISCUSSION...POTENTIALLY EXPLOSIVE THUNDERSTORM DEVELOPMENT IS

POSSIBLE OVER THE NEXT FEW HOURS AS GRADUALLY DEEPENING SURFACE LOW

TRACKS EAST ALONG A FRONTAL ZONE SITUATED FROM NORTHEAST IOWA

EASTWARD ALONG THE WI/IL BORDER TO LAKE MICHIGAN. A VOLATILE WARM

AND VERY MOIST AIRMASS SHOULD FUEL INTENSE THUNDERSTORM UPDRAFTS

ACROSS THESE AREAS WHERE MID LEVEL FLOW IN EXCESS AROUND 50KT

SUPPORTS UPDRAFT PERSISTENCE AND ORGANIZATION. A NUMBER OF

SUPERCELLS ARE EXPECTED PRIOR TO A CONSOLIDATION OF STORMS INTO A

LARGE MCS TOWARD EVENING. LOW LEVEL SHEAR/HELICITY NEAR THE SURFACE

LOW AND ALONG THE FRONT WILL SUPPORT SOME TORNADOES WITH ANY

DISCRETE CELLS. A COUPLE STRONG TORNADOES SEEM POSSIBLE WITHIN THIS

ENVIRONMENT OVER THE NEXT SEVERAL HOURS IN ADDITION TO VERY LARGE

HAIL AND LOCALIZED DOWNDRAFT/DAMAGING WIND THREATS.



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 28030.





...CARBIN

