URGENT - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WATCH NUMBER 375 NWS STORM PREDICTION CENTER NORMAN OK 335 PM CDT MON JUN 30 2014
THE NWS STORM PREDICTION CENTER HAS ISSUED A
* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF NORTHERN AND EASTERN ILLINOIS NORTHWEST AND NORTH CENTRAL INDIANA SOUTHWEST LOWER MICHIGAN EASTERN WISCONSIN LAKE MICHIGAN
* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 335 PM UNTIL 900 PM CDT.
...THIS IS A PARTICULARLY DANGEROUS SITUATION...
* PRIMARY THREATS INCLUDE... WIDESPREAD DAMAGING WINDS AND SCATTERED SIGNIFICANT GUSTS TO 80 MPH LIKELY ISOLATED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE A TORNADO OR TWO POSSIBLE
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHEAST OF MILWAUKEE WISCONSIN TO 65 MILES SOUTH SOUTHWEST OF VALPARAISO INDIANA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
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OTHER WATCH INFORMATION...CONTINUE...WW 373...WW 374...
DISCUSSION...FAR ERN IA DERECHO-PRODUCING MCS EXPECTED TO MOVE MAINLY E THROUGH EARLY TNGT. THE CONVECTIVE SYSTEM WILL ENCOUNTER SLIGHTLY LESS UNSTABLE LOW-LVL ENVIRONMENT OVER NE IL/SE WI RELATIVE TO THAT OVER ERN IA/WRN IL. BUT GIVEN EXISTING STRENGTH OF CONVECTIVE SYSTEM...AND LIKELIHOOD FOR SOME INCREASE IN THE MEAN FLOW OVER NRN IL AS NW MO UPR IMPULSE APPROACHES...EXPECTED AN ORGANIZED BAND OF SVR STORMS TO CONTINUE E AT LEAST AS FAR AS LK MI. BACKING OF DEEP FLOW AHEAD OF MO IMPULSE...AND CONTINUED NWD SPREAD OF LOW-LVL MOISTURE...FURTHER SUGGEST THAT THE SQLN COULD BUILD A BIT FARTHER N INTO WI WITH TIME.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM MOTION VECTOR 27045.
