

112 

WWUS20 KWNS 290023

SEL3

SPC WW 290023

INZ000-290400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 433

NWS STORM PREDICTION CENTER NORMAN OK

725 PM CDT THU JUN 28 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWEST INDIANA



EFFECTIVE THIS THURSDAY EVENING FROM 725 PM UNTIL 1100 PM 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 20

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES WEST OF

VALPARAISO INDIANA TO 35 MILES EAST SOUTHEAST OF VALPARAISO

INDIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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.



DISCUSSION...AN ISOLATED INTENSE THUNDERSTORM HAS FORMED ALONG THE

LAKE BREEZE NEAR CHI.  THIS STORM IS EXPECTED TO TRACK

EAST-SOUTHEASTWARD INTO NORTHWEST IND DURING THE NEXT HOUR OR TWO.

DESPITE THE STORMS LIMITED AREAL COVERAGE...EXTREME INSTABILITY AND

FAVORABLE EFFECTIVE SHEAR VALUES SUGGEST THE POTENTIAL FOR SUPERCELL

STRUCTURES.  LARGE HAIL AND DAMAGING WINDS APPEAR TO BE THE MAIN

THREAT...ALTHOUGH A BRIEF TORNADO CANNOT BE RULED OUT.



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 600. MEAN STORM

MOTION VECTOR 29025.





...HART

