

855 

WWUS20 KWNS 302038

SEL5

SPC WW 302038

ILZ000-INZ000-MIZ000-WIZ000-LMZ000-010200-



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.



&&



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.





...CORFIDI

