

929 

WWUS20 KWNS 182151

SEL7

SPC WW 182151

MIZ000-LHZ000-LMZ000-190500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 407

NWS STORM PREDICTION CENTER NORMAN OK

550 PM EDT MON JUN 18 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN LOWER MICHIGAN

       LAKE HURON

       LAKE MICHIGAN



EFFECTIVE THIS MONDAY AFTERNOON AND TUESDAY MORNING FROM 550 PM

UNTIL 100 AM EDT.



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 70

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

PELLSTON MICHIGAN TO 35 MILES SOUTH SOUTHWEST OF HOUGHTON LAKE

MICHIGAN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 406...



DISCUSSION...STRONG TO SEVERE TSTMS AHEAD OF AN ADVANCING COLD FRONT

WILL MOVE ACROSS NRN LOWER MI THROUGH THE EVENING HOURS WITH THE

THREAT OF DAMAGING WINDS AND HAIL. AIR MASS ACROSS THE REGION HAS

HAD TIME TO DESTABILIZE IN THE WAKE OF MORNING STORMS AND THIS

SHOULD ALLOW CONVECTION NOW CROSSING NRN LAKE MI TO REMAIN

RELATIVELY INTENSE.  ANTECEDENT SHEAR SUPPORTIVE OF UPDRAFT

PERSISTENCE AND FAST STORM MOTIONS CONFIRMS STORM-SCALE GUIDANCE

THAT IS REMARKABLY CONSISTENT IN MAINTAINING WELL-ORGANIZED STORMS

EAST ACROSS THE WATCH AREA OVER THE NEXT SEVERAL HOURS. WHILE

STRAIGHT-LINE WINDS FROM THIS ACTIVITY APPEAR TO BE THE PRIMARY

HAZARD...ANY DISCRETE CELLS WILL NEED TO BE MONITORED CAREFULLY FOR

STRONGER ROTATION WITH A FEW  FORECAST SOUNDINGS IN THE REGION

INDICATING POCKETS OF GREATER LOW LEVEL HODOGRAPH CURVATURE THAT

COULD RESULT IN A TORNADO...IN ADDITION TO LARGE 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 500. MEAN STORM

MOTION VECTOR 26035.





...CARBIN

