MESOSCALE PRECIPITATION DISCUSSION 0311
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
402 AM EDT MON JUL 06 2015
 
AREAS AFFECTED...SOUTHEAST MN...WESTERN WI 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 060755Z - 061200Z
 
SUMMARY...LOCALIZED FLASH FLOODING IS POSSIBLE OVER THE NEXT
COUPLE OF HOURS AS INTENSE SHOWERS AND THUNDERSTORMS GRADUALLY
SHIFT SOUTH AND EAST.

DISCUSSION...IR SATELLITE AND RADAR IMAGERY SHOWS CONVECTION
BECOMING A BIT MORE CONCENTRATED OVER THE LAST COUPLE OF HOURS
ACROSS PORTIONS OF SOUTHEAST MN...FROM JUST SOUTHWEST OF KMSP
EAST-NORTHEAST INTO FAR WESTERN WI NEAR KOEO. CLOUD TOP
TEMPERATURES HAVE COOLED JUST A TAD AND THERE HAVE BEEN A COUPLE
OF OVERSHOOTING TOPS DETECTED USING THE GOES-OTD ALGORITHM.

THE CONVECTION HAS BEEN RATHER WELL ORGANIZED OVERNIGHT AND
CONTINUES IN ASSOCIATION WITH A SHORTWAVE TROUGH MOVING ACROSS THE
NORTHERN PLAINS ALONG WITH A WAVE OF LOW PRESSURE ADVANCING EAST
ALONG A FRONTAL ZONE. THE LATEST SURFACE ANALYSIS SUGGESTS
MULTIPLE WAVES...WITH ONE LOW ENTERING EXTREME NORTHWEST IA...AND
ANOTHER ONE ASSOCIATED WITH THE STRONGER CONVECTION OVER SOUTHEAST
MN NEAR KMSP.

THE HIRES MODELS ARE NOT EXACTLY HANDLING THE CONVECTION OVER
SOUTHEAST MN AND FAR WESTERN WI THAT WELL...AS THE ACTIVITY HAS
BEEN TENDING TO MAINTAIN A SOLID LEVEL OF ORGANIZATION AND IS
SHIFTING FARTHER SOUTH AND EAST THAN EARLIER PREDICTED. THE 00Z
ARW AND 00Z NMMB BOTH HAD A MORE DISORGANIZED CHARACTER TO THE
ACTIVITY OVER THESE AREAS. IN THE CASE OF THE 06Z HRRR...ITS
CONVECTIVE AXIS IS TOO FAR NORTH AND WEST.

GIVEN THE PRESENCE OF THE WAVE NEAR KMSP...AND WITH STRONG LOW
LEVEL JET ENERGY/MOISTURE CONVERGENCE AIMED INTO SOUTHEAST MN WITH
A SOUTHWEST LOW LEVEL JET AS PER VAD WIND PROFILER DATA REACHING
40 TO 50 KTS...THE CONVECTION OVER SOUTHEAST MN AND FAR WESTERN WI
SHOULD REMAIN ORGANIZED AND FOCUSED IN A MANNER THAT WILL FAVOR
LOCALLY VERY HEAVY RAINFALL AMOUNTS. PWATS OVER 1.75 INCHES
COUPLED WITH ANY OVERSHOOTING TOPS WILL FAVOR EXTREMELY INTENSE
RAINFALL RATES.

EXPECT THE POTENTIAL LOCALLY FOR 3 TO 5 INCH RAINFALL TOTALS AND
ISOLATED HEAVIER AMOUNTS THROUGH 12Z AS THE CONVECTION CONTINUES
ALONG THE FRONT. FLASH FLOODING IS POSSIBLE AT LEAST LOCALLY AS A
RESULT.

ORRISON

ATTN...WFO...ARX...DLH...MPX...

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

LAT...LON   45899134 45819046 45169025 44919068 44409180 
            43859322 43829365 43919388 44109395 44389397 
            44909385 45569275