MESOSCALE PRECIPITATION DISCUSSION 0643
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
510 AM EDT TUE SEP 06 2016
 
AREAS AFFECTED...SOUTHERN MN...NORTHWEST WI 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 060910Z - 061415Z
 
SUMMARY...FAVORED ORIENTATION OF CONVECTION FOR SOME
TRAINING/REPEAT RAINFALL OVER LOWER GUIDANCE SUGGESTS POSSIBLE
ISOLATED FLASH FLOODING THREAT. 

DISCUSSION...WV LOOP INDICATES SUBTLE SHORTWAVE AND ASSOCIATED
ANTICYCLONIC DIFFLUENCE MAXIMA WITHIN THE STRONG SWLY 110 KT JET. 
WSW 30-35KT LLJ IS SLOWLY WEAKENING BUT WITH SOME WEAK MID-LEVEL
HEIGHT FALLS HAS SOME WEAK BACKING TO SUPPORT MST CONVERGENCE
ALONG THE BOUNDARY TO MAINTAIN A BAND OF ELEVATED CONVECTION FROM
SD/MN CENTRAL BORDER TOWARD SCATTERED BUT INCREASING
WAA/ISENTROPIC CONVECTION NEAR THE TWIN CITIES EXTENDING INTO NW
WI ATTM.  THE ALIGNMENT OF DEEP AND INCREASING UNIDIRECTIONAL FLOW
AS THE WAVE SHEARS OUT...IS FAVORABLY ORIENTED TO THE BOUNDARY AND
SURFACE TROF THAT HAS BEEN FOCUSING THE CONVECTION SO FAR.  THIS
WILL SUPPORT TRAINING OF CONVECTION TO COMPOUND TOTALS TO AROUND
2-3" POSSIBLE EVEN AS RATES REDUCE WITH LIMITING INSTABILITY AND
WEAKENED CONVERGENCE; FLASH FLOODING REMAINS POSSIBLE GIVEN THE
LOWER GUIDANCE ACROSS S MN PARTICULARLY IN PRONE URBAN CENTERS. 
THREAT OF FLASH FLOODING IS REDUCED INTO N WI/UP OF MI GIVEN
CAPABILITY TO ABSORB THIS LEVEL OF RAINFALL.  

GALLINA

ATTN...WFO...ABR...DLH...FSD...MPX...

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

LAT...LON   45819231 45779083 44839135 44409328 43939558 
            44309623 44759645 45119618 45629381