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184 

WWUS20 KWNS 182344

SEL1

SPC WW 182344

MIZ000-LHZ000-LMZ000-LSZ000-190500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 421

NWS STORM PREDICTION CENTER NORMAN OK

750 PM EDT THU JUL 18 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  UPPER AND NORTHERN LOWER MICHIGAN

  LAKE HURON

  LAKE MICHIGAN

  LAKE SUPERIOR



* EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 750 PM

  UNTIL 100 AM EDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES NORTHWEST

OF ESCANABA MICHIGAN TO 50 MILES SOUTHEAST OF SAULT STE MARIE

MICHIGAN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 420...



DISCUSSION...THUNDERSTORMS OVER SOUTHERN LAKE SUPERIOR WILL SPREAD

SOUTHEASTWARD ACROSS UPPER MI AND NORTHERN LOWER MI THIS EVENING.

STRONG INSTABILITY COUPLED WITH FAVORABLE WINDS ALOFT WILL SUPPORT A

RISK OF A FEW SEVERE STORMS CAPABLE OF DAMAGING WINDS AND HAIL.



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 450. MEAN STORM

MOTION VECTOR 28035.





...HART

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