MESOSCALE PRECIPITATION DISCUSSION 0300
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
417 PM EDT TUE AUG 19 2014
 
AREAS AFFECTED......LOWER MI... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 192016Z - 200016Z
 
SUMMARY...CONVECTION MOVING THROUGH A HIGH MOISTURE CONTENT
ENVIRONMENT MAY PRODUCE AS MUCH AS 2 INCHES OF RAINFALL IN AN
HOUR. THIS MUCH RAINFALL COULD RESULT IN FLASH FLOODING THROUGH
00Z.

DISCUSSION...INTENSIFYING CONVECTION MOVING THROUGH THE LOWER
PENINSULA OF MI HAS PRODUCED AS MUCH AS 2 INCHES OF RAINFALL IN AN
HOUR (PER SPOTTER REPORTS) IN AN ENVIRONMENT OF 1.60 INCH
PRECIPITABLE WATER AIR. THE IR LOOP SHOWS COOLING TOPS...AND AS
THE CONVECTION CONTINUES DEVELOPING/MOVING THROUGH THE
REGION...THERE IS THE POTENTIAL FOR TRAINING...POSING THE
POTENTIAL FOR FLASH FLOODING.

PRECIPITABLE WATER VALUES PEAK NEAR 1.75 INCHES IN THE LOW LEVEL
SOUTHWEST FLOW AHEAD OF THE COLD FRONT. THERE IS A MULTI MODEL
SIGNAL IN THE HIGH RESOLUTION GUIDANCE (SUCH AS THE 19Z HRRR...12Z
ARW...NMM AND CONEST) FOR LOCAL 2 TO 4 INCH RAINFALL AMOUNTS
THROUGH 00Z.

ONE HOUR FLASH FLOOD GUIDANCE VALUES ARE AS LOW AS 1.00 TO 1.50
INCHES...ESPECIALLY ACROSS THE EASTERN HALF OF THE AREA. THE
CONVECTION IS MOVING ALONG AT PRESENT...BUT THERE ARE INDICATIONS
IT MAY SLOW AS IT APPROACHES THE EASTERN PORTION OF THE LOWER
PENINSULA...RAISING THE THREAT FOR TRAINING.
GIVEN THE COMBINATION OF RELATIVELY LOW FLASH FLOOD GUIDANCE AND
OBSERVED HIGH RAINFALL RATES...FLASH FLOODING IS POSSIBLE.  

HAYES

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

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

LAT...LON   43098620 43328606 43798548 43898483 43958395 43608254
            42728217 42268232 41798368 41868535 42228618 42798622
            43108621 43098620