MESOSCALE DISCUSSION 1389, AREAS AFFECTED...LOWER MI CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

MESOSCALE DISCUSSION 1389
   NWS STORM PREDICTION CENTER NORMAN OK
   0259 PM CDT WED JUL 04 2012
   
   AREAS AFFECTED...LOWER MI
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 041959Z - 042130Z
   
   PROBABILITY OF WATCH ISSUANCE...60 PERCENT
   
   SUMMARY...A SEVERE THREAT MAY DEVELOP AS STORMS INITIATE ACROSS
   CNTRL LOWER MI THIS AFTERNOON. WIND DAMAGE AND LARGE HAIL WILL
   LIKELY BE THE PRIMARY THREATS. WW ISSUANCE WILL BE POSSIBLE ONCE
   CERTAINTY INCREASES CONCERNING THE LOCATION OF THE GREATEST SEVERE
   THREAT.
   
   DISCUSSION...THE LATEST SFC ANALYSIS SHOWS A ZONE OF CONFLUENCE
   LOCATED ACROSS CNTRL LOWER MI WHERE A VERY MOIST AIRMASS IS IN
   PLACE. SFC DEWPOINTS ARE IN THE MID 70S F EXTENDING FROM NORTH OF
   MUSKEGON ESEWD TO NEAR FLINT. MESOANALYSIS ALONG THIS CORRIDOR
   ESTIMATES MLCAPE VALUES ARE IN THE 3000 TO 4500 J/KG RANGE AND THIS
   SHOULD BE THE FAVORED AREA FOR INITIATION THIS AFTERNOON. IN
   ADDITION...WATER VAPOR IMAGERY SHOWS A DISTURBANCE MOVING ESEWD INTO
   LOWER MI FROM THE NRN PART OF LAKE MICHIGAN WHICH SHOULD HELP TO
   INCREASE STORM COVERAGE ONCE STORMS INITIATE. THE LATEST WSR-88D
   VWPS ACROSS LOWER MI SHOW UNIDIRECTIONAL WIND PROFILES WITH 30 KT OF
   FLOW IN THE MID-LEVELS WHICH SHOULD BE SUFFICIENT FOR A WIND DAMAGE
   THREAT ESPECIALLY IF A LINE SEGMENT CAN DEVELOP. ISOLATED LARGE HAIL
   WILL ALSO BE POSSIBLE ESPECIALLY IF ANY OF THE STORMS CAN EXHIBIT
   ROTATION.
   
   ..BROYLES/THOMPSON.. 07/04/2012
   
   
   ATTN...WFO...DTX...APX...GRR...
   
   LAT...LON   43818256 44538389 44538573 44058654 43578647 43218542
               42968460 42568363 42538260 43048226 43818256