SPC MESOSCALE DISCUSSION 1104 FOR PORTIONS OF LOWER PENINSULA OF
MICHIGAN CONCERNING...SEVERE THUNDERSTORM POTENTIAL...

VALID 101744Z - 102000Z

THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS ERN PORTIONS OF THE
LOWER PENINSULA OF MI. ISOLATED SEVERE CONVECTION WILL BE POSSIBLE
OVER THE NEXT COUPLE OF HOURS...WITH THE SEVERE THREAT INCREASING
THROUGH THE LATE AFTERNOON HOURS. WE WILL CONTINUE TO MONITOR THE
AREA FOR A POSSIBLE WW.

LATEST REGIONAL VWP/S INDICATE FAIRLY WEAK DEEP LAYER SHEAR IS
PRESENT ACROSS THE AREA. HOWEVER...STRONGER MID LEVEL WAA OUT AHEAD 
OF MCV MOVING ACROSS WI WAS AIDING IN ENOUGH LIFT TO GENERATE
ELEVATED CONVECTION OVER PORTIONS OF CENTRAL MI. LATEST SURFACE
ANALYSIS INDICATES THAT A WARM FRONTAL BOUNDARY WAS SHIFTING SLOWLY
NEWD FROM NEAR LUDINGTON MI EWD TO NEAR THE SAGINAW VALLEY...THEN
SEWD TO NEAR THE DETROIT METRO AREA. TO THE SOUTH OF THE
FRONT...TEMPERATURES WARMING INTO THE UPPER 70S/LOWER
80S...COMBINED DEWPTS IN THE LOWER 60S...HAVE CONTRIBUTED TO
MODERATE INSTABILITY WITH SBCAPES NEAR 2000 J/KG. ELEVATED STRONG
CONVECTION MOVING EWD INTO THE SAGINAW VALLEY MAY CONTINUE TO
INTENSIFY WHILE TRYING TO BECOME ROOTED IN THE BOUNDARY LAYER ALONG
AFOREMENTIONED BOUNDARY. ALTHOUGH STORM ORGANIZATION SEEMS SOMEWHAT
MARGINAL...STEEP MID LEVEL LAPSE RATES WILL AID IN THE POTENTIAL
FOR SOME ISOLATED HAIL WITH THE STRONGEST STORMS. OTHER CONVECTION
MAY BEGIN TO DEVELOP ALONG SURFACE FRONTAL BOUNDARY NEAR LUDINGTON
OVER THE NEXT FEW HOURS...THEN PROPAGATE SEWD THROUGH CENTRAL LOWER
MI LATER THIS AFTERNOON.

..CROSBIE.. 06/10/01