Graphic for MPD #0374

MESOSCALE PRECIPITATION DISCUSSION 0374
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
214 AM EDT FRI JUN 23 2017

AREAS AFFECTED...CENTRAL LOWER PENINSULA OF MI

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 230613Z - 231143Z

SUMMARY...THUNDERSTORMS WITH HEAVY RAIN CONTINUE MOVING ACROSS THE
AREA FROM WEST TO EAST.  HOURLY RAIN RATES UP TO 1.5", WITH LOCAL
AMOUNTS UP TO 3", ARE EXPECTED OVER SATURATING SOILS.

DISCUSSION...THUNDERSTORMS WITH HEAVY RAIN CONTINUE MOVING ACROSS
THE AREA FROM WEST TO EAST, WITH NEW DEVELOPMENT NOTED OVER LAKE
MI AS OF LATE.  THE LEADING EDGE OF AN UPPER LOW IS MOVING INTO
NORTHWEST AND NORTH-CENTRAL WI, WHICH IS ACTING AS THE TRIGGER FOR
DIVERGENCE ALOFT.  MESOSCALE WAVES ARE SEEN ALONG A FRONTAL
BOUNDARY ACROSS LOWER MI.  PRECIPITABLE WATER VALUES ARE ~1.75"
PER RECENT GPS DATA.  INFLOW AT 850 HPA IS WEST-SOUTHWEST AT 30-40
KTS PER VAD WIND PROFILES.  EFFECTIVE BULK SHEAR IS ~30 KTS. 
MUCAPE VALUES ARE 500-1000 J/KG, WHICH REMAIN EFFECTIVE FOR HEAVY
RAIN ISSUES GIVEN THE SATURATED ATMOSPHERE IN THE REGION.

THE AVAILABLE BULK SHEAR AND NEARLY UNIDIRECTIONAL WESTERLY FLOW
WITH HEIGHT SUPPORT THE IDEA OF CONTINUED WEST TO EAST TRAINING,
ELEVATED NORTH OF THE FRONTAL BOUNDARY.  THE MESOSCALE GUIDANCE IS
NOT OVERLY BULLISH WITH AMOUNTS IN THIS REGION, SHOWING LOCAL
AMOUNTS IN THE 1.5-2" RANGE THROUGH 12Z.  WITH SLOWLY DECLINING
INSTABILITY, BELIEVE THE RAIN EVENT IN THIS AREA WILL EVOLVE INTO
ONE OF LONGER DURATION OVER THE NEXT SEVERAL HOURS.  ENOUGH
INSTABILITY IS EXPECTED TO BE LEFT TO LEAD TO HOURLY RAIN RATES UP
TO 1.5", WITH LOCAL AMOUNTS UP TO 3", OVER SATURATING SOILS.

ROTH

ATTN...WFO...APX...DTX...GRR...

ATTN...RFC...NCRFC...

LAT...LON   44168461 44078275 43708254 43288248 42818258
            42748387 42838635 43558672 44108654


Last Updated: 214 AM EDT FRI JUN 23 2017