MESOSCALE PRECIPITATION DISCUSSION 0114
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1158 PM EDT THU JUN 20 2013
 
AREAS AFFECTED...SOUTHEAST ND...NORTHEAST SD...CENTRAL
MN...NORTHWEST WI 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 210358Z - 210800Z
 
SUMMARY...THUNDERSTORMS WITH HEAVY RAIN ARE FORMING CLOSER TO A
FRONTAL BOUNDARY, ORIENTED EAST-WEST THROUGH SOUTH-CENTRAL MN. 
LOCAL RAINFALL AMOUNTS OF 3-6 INCHES WITHIN A SHORT TIME FRAME
WILL LEAD TO FLASH FLOODING. 

DISCUSSION...A STATIONARY FRONT EXTENDS FROM NEAR THE EASTERN
SD/ND BORDER EASTWARD THROUGH SOUTH-CENTRAL MINNESOTA.  THE REGION
IS QUITE DIVERGENT ALOFT TO THE EAST-SOUTHEAST OF AN UPPER LEVEL
LOW.  INFLOW AT THE 850 HPA LEVEL IS ON THE ORDER OF 40 KNOTS FROM
THE SOUTH, WHICH HAS LED TO PRECIPITABLE WATER VALUES OF 1.75-2
INCHES POOLING NEAR THE SURFACE FRONT.  SIGNIFICANT INSTABILITY
EXISTS WITHIN THE SYSTEM'S WARM SECTOR, WITH SATELLITE-DERIVED
CAPE VALUES IN THE 5000-6000 J/KG RANGE.  THIS CONVECTIVE SYSTEM
HAS SHOWN A RECENT HISTORY OF PRODUCING 3-6 INCHES OF RAINFALL
ACROSS EASTERN ND.  THE LINGERING PROBLEMS FROM A FLASH FLOOD
PERSPECTIVE OVER THE NEXT SEVERAL HOURS ARE THE MOBILE 850 HPA
LOW-LEVEL JET WHICH SHOULD LIMIT BACKBUILDING, AND WHETHER OR NOT
ARCED BANDS DEVELOP PERPENDICULAR TO THE MEAN THUNDERSTORM MOTION
WHICH WOULD LIMIT FLASH FLOODING POTENTIAL.  SINCE THE CONVECTION
HAS RECENTLY TRIED ORGANIZING ALONG A SOLID WEST-NORTHWEST/
EAST-SOUTHEAST AXIS -- ALONG ITS EXPECTED PROPAGATION -- OPTED FOR
LIKELY WORDING FOR THIS MESOSCALE PRECIPITATION DISCUSSION.

ROTH

ATTN...WFO...DLH...MPX...FGF...ABR...BIS...

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

LAT...LON   45179490 45319650 45579773 45739883 46049924 46669840
            47329625 47159386 46309243 45189280 45179490