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891 

WWUS20 KWNS 070629

SEL0

SPC WW 070629

MIZ000-LHZ000-LMZ000-071400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 480

NWS STORM PREDICTION CENTER NORMAN OK

130 AM EST WED AUG 7 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  SOUTHERN LOWER MICHIGAN

  LAKE HURON

  LAKE MICHIGAN



* EFFECTIVE THIS WEDNESDAY MORNING FROM 130 AM UNTIL 900 AM EST.



* PRIMARY THREATS INCLUDE...

  SEVERAL SIGNIFICANT DAMAGING WIND GUSTS TO 80 MPH POSSIBLE

  A FEW LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 85

STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES EAST

NORTHEAST OF TRAVERSE CITY MICHIGAN TO 30 MILES SOUTH OF ROBEN

HOOD MICHIGAN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 478...WW 479...



DISCUSSION...A WELL-DEVELOPED SQUALL-LINE WILL MOVE QUICKLY EASTWARD

ACROSS LOWER MICHIGAN EARLY THIS MORNING. STRONG DEEP LAYER

SHEAR...MODERATE INSTABILITY AND A WELL-DEFINED LOW TO MID-LEVEL JET

STRUCTURE BEHIND THE SYSTEM WILL RESULT IN A WIND DAMAGE THREAT AS

THE LINE MOVES ACROSS LOWER MICHIGAN.



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 500. MEAN STORM

MOTION VECTOR 28055.





...BROYLES

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