MESOSCALE PRECIPITATION DISCUSSION 0149
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
939 PM EDT THU MAY 28 2015
 
AREAS AFFECTED......NORTHEAST SD/SOUTHEAST ND/NORTH CENTRAL MN... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 290140Z - 290530Z
 
SUMMARY...TRAINING LINES OF CONVECTION AHEAD OF A SURFACE TROUGH
EXTENDING ACROSS SD AND ND COULD RESULT IN FLASH FLOODING.

SUMMARY...LINES OF CONVECTION HAVE DEVELOPED IN AN AXIS OF
INSTABILITY (THE 00Z ABR SOUNDING SHOWED SBCAPE VALUES OVER 2000
J/KG) EXTENDING FROM NORTHEAST SD THROUGH SOUTHEAST ND INTO NORTH
CENTRAL MN. THE CONVECTION IS TAPPING PRECIPITABLE WATER VALUES
NEAR 1.25 INCHES TO PRODUCE LINES OF CONVECTION AHEAD OF A SURFACE
TROUGH. THE CONVECTION IS PRODUCING LOCALLY HEAVY RAINFALL...WITH
THE KABR RADAR INDICATING HOURLY RATES NEAR 2 INCHES OVER
SOUTHEAST ND. THESE VALUES MAY BE HAIL CONTAMINATED... GIVEN THE
STRONG INSTABILITY IN PLACE.

THERE IS A MULTI MODEL SIGNAL FOR THE INSTABILITY AND MOISTURE TO
REMAIN IN PLACE AHEAD OF THE SURFACE TROUGH INTO THE EARLY MORNING
HOURS. UPPER DIFFLUENCE AHEAD OF A SHORT WAVE TRACKING THROUGH
SOUTH CENTRAL CANADA PROVIDES SYNOPTIC SCALE ASCENT...SO THE
ACTIVITY SHOULD EXPAND IN COVERAGE IN THE NEXT FEW HOURS.

THE LATEST HRRR...AS WELL AS THE 12Z ARW WRF...SUGGEST THE
POTENTIAL FOR UP TO 2 INCHES OF RAINFALL WITH THE CONVECTION. THIS
IS MOST LIKELY TO OCCUR IN AREAS WHERE THE CONVECTION TRAINS...AND
GIVEN THE UNIDIRECTIONAL FLOW SEEN ON THE 00Z KABR SOUNDING...THE
POTENTIAL FOR TRAINING SHOULD CONTINUE. SINCE ONE AND THREE HOUR
FLASH FLOOD VALUES ARE AS LOW AS 1.00 TO 1.50 INCHES ACROSS
PORTIONS OF SOUTHEAST ND... FLASH FLOODING IS CONSIDERED POSSIBLE.

HAYES

ATTN...WFO...ABR...BIS...FGF...

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

LAT...LON   47849685 47809505 47019524 46099637 45459755 
            45279849 44969902 45169938 45659961 45659961 
            46459904 46529893 46869842 47289784 47719720 
            
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