MESOSCALE PRECIPITATION DISCUSSION 0310
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
219 AM EDT SUN JUN 17 2018

AREAS AFFECTED...NORTHERN MN TO NORTHWEST WI

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 170618Z - 171200Z

SUMMARY...ON GOING FLASH FLOODING FROM NORTHERN MN INTO NORTHWEST
WI WILL CONTINUE THROUGH THE REMAINDER OF THE OVERNIGHT HOURS
BEFORE GRADUALLY TAPERING OFF. 

DISCUSSION...CONVECTION WITH RAINFALL RATES OF 1 TO 2 INCHES PER
HOUR HAS BEEN PERSISTENT IN A STRIPE FROM NORTHWEST MN TOWARDS THE
SOUTHERN TIP OF LAKE SUPERIOR AND ON INTO NORTHWEST WI.  THIS AREA
WAS LOCATED NORTH OF AN ELEVATED WARM FRONT.  THINKING IS THAT THE
HEAVY RAIN AND FLASH FLOODING WILL PERSIST PRETTY MUCH ALONG THE
SAME LINE THROUGH 12Z...WITH ONLY A GRADUAL DECREASE IN AREAL
COVERAGE AND RAINFALL INTENSITY LATER.  GOES IR IMAGERY STILL
SHOWED A GRADUAL WARMING OF CLOUD TOP TEMPERATURES NEAR THE
NORTHWEST MN/SOUTHEAST ND BORDER WITH COLDER TEMPS AND MORE
INTENSE RAINFALL TO THE EAST OF THERE.  MANY OF STORMS HAVE BEEN
FORMING AND PROPAGATING ALONG A WELL DEFINED DEWPOINT/THETAE
GRADIENT. 

THE HIGH RESOLUTION...CONVECTIVE ALLOWING MODELS SUGGEST ANOTHER 2
INCHES ARE POSSIBLE ACROSS THE FAR NORTHWESTERN PART OF WI.  THIS
AREA IN PARTICULAR WAS MOST VULNERABLE TO FLASH FLOODING GIVEN
HEAVY RAINFALL THERE WITHIN THE PAST 48 HOURS.  WITH CELLS
TRAINING AND MULTIPLE ROUNDS OF CONVECTION...ANY ON GOING FLASH
FLOODING WILL BE WORSENED WITH THE POTENTIAL FOR FLASH FLOODING TO
BEGIN ELSEWHERE.

IN ADDITION...INDUCED WAVES ALONG THE FRONT WILL FOCUS
STORMS/INFLOW WHILE THE PARALLEL ORIENTATION OF THE FLOW ALOFT TO
THAT OF THE FRONT AND CONVECTION FAVORS A THREAT OF CELL TRAINING
AND REPEAT CELLS OVER TIME. 

BANN

ATTN...WFO...DLH...FGF...GRB...MPX...MQT...

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

LAT...LON   47049538 46929245 46709020 46168911 45738938
            45619065 45589207 45999432 46089563 46359672
            46779668