MESOSCALE PRECIPITATION DISCUSSION 0113
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
906 PM EDT THU JUN 20 2013
 
AREAS AFFECTED...EASTERN ND...NORTHWEST AND WEST CENTRAL
MN...NORTHEAST SD 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 210105Z - 210400Z
 
SUMMARY...THERE IS AN INCREASING THREAT OF FLASH FLOODING OVER
PARTS OF SOUTHEAST ND...NORTHEAST SD AND NORTHWEST AND WEST
CENTRAL MN THROUGHOUT THE EVENING. 

VERY UNSTABLE AIRMASS OVER THE CENTRAL PLAINS WILL CONTINUE TO
FEED A GROWING AREA OF THUNDERSTORMS NORTH OF A WEST TO EAST
ORIENTED WARM FRONT.  00Z SOUNDING SHOWED AT LEAST 30 KTS OF FLOW
TAPPING PW VALUES OF 1.25 TO 1.75 FROM KS/NEB INTO THE EASTERN
DAKOTAS AND WESTERN MN.  A TIGHT GRADIENT OF THETAE SUGGESTS THAT
THE STORMS WHICH WERE FORMING AS OF 21/01Z WILL CONTINUE TO
PRODUCE MODERATE TO HEAVY RAINFALL AS THEY MOVE SLOWLY TOWARDS THE
EAST OR SOUTHEAST. 

RAINFALL AMOUNTS THROUGH 21/04Z LOOK TO BE ON THE ORDER OF 4
INCHES BASED ON HIGH RAINFALL RATES AND SLOW MOVING CELLS...WITH
ISOLATED MAXIMUM AMOUNTS POSSIBLE.  THIS WAS ALSO CLOSE TO THE
20/21Z HRRR AND 20/12Z GFS.
 
BANN

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

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

LAT...LON   45049648 45979817 47029853 47739692 47699440 45859468
            45049648