MESOSCALE PRECIPITATION DISCUSSION 0266
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1153 PM EDT TUE JUN 05 2018

AREAS AFFECTED...SRN ND...NRN SD INTO WRN MN

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 060350Z - 060915Z

SUMMARY...CONTINUED DEVELOPMENT OF CONVECTION ACROSS THE DAKOTAS
MAY EVOLVE INTO FLASH FLOODING FOR A FEW LOCATIONS FROM SOUTHERN
ND...NORTHERN SD INTO WESTERN MN. 2-3 INCHES OF RAIN...LOCALLY
HIGHER...CAN BE EXPECTED THROUGH 09Z.

DISCUSSION...REGIONAL RADAR FROM 03Z SHOWED A FEW AREAS OF
CONVECTION CONVERGING OVER WESTERN SD NEAR A COLD FRONT THAT
STRETCHED FROM EASTERN ND INTO WESTERN SD. AN EASTWARD MOVING
MID-UPPER LEVEL SHORTWAVE WAS EVIDENT IN WATER VAPOR IMAGERY OVER
SOUTHERN SASKATCHEWAN WITH 00Z UPPER AIR DATA AND RAP ANALYSES
INDICATING AN ASSOCIATED JET STREAK WITH 60-70 KT BETWEEN 500-300
MB NEAR THE U.S./CANADIAN BORDER. 00Z SOUNDINGS FROM BIS AND ABR
SHOWED A FAIR DEGREE OF DRY AIR BELOW 500 MB WHICH WHEN COMBINED
WITH SUFFICIENT DIRECTIONAL SHEAR IN THE LOW-MID LEVELS...HAS
ALLOWED CONVECTION TO BE LARGELY OUTFLOW DOMINANT THROUGH THE
EARLY OVERNIGHT HOURS.

SHORT TERM FORECASTS FROM THE RAP SUPPORT INCREASING 850-700 MB
LOW LEVEL MOISTURE TRANSPORT INTO THE EASTERN DAKOTAS BETWEEN
06-09Z ALONG WITH A SLIGHT STRENGTHENING OF THE AFOREMENTIONED
MID-UPPER LEVEL JET STREAK WITHIN AN INCREASINGLY DIFFLUENT FLOW
PATTERN ALOFT. THESE FACTORS SHOULD HELP TO SUPPORT ADDITIONAL
CONVECTION OVER SOUTHEASTERN NORTH DAKOTA OVER THE NEXT COUPLE OF
HOURS WHICH SHOULD MEET WITH ONGOING CONVECTION IN NORTHWESTERN SD
WHICH IS MOVING TO THE EAST. GIVEN DECREASING DIRECTIONAL SHEAR
BETWEEN THE 850-700 MB AND CLOUD BEARING LAYER MEAN WIND
VECTORS...THE ENVIRONMENT MAY SUPPORT PERIODS OF TRAINING ALONG
WITH CELL MERGERS WHICH COULD ALLOW FOR A FLASH FLOODING FOR ONE
OR TWO LOCATIONS. 2-3 INCH RAINFALL TOTALS WILL BE
POSSIBLE...LOCALLY HIGHER...THROUGH APPROXIMATELY 09Z.

OTTO

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

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

LAT...LON   47309694 47289484 47069390 46549369 46089406
            45329686 44700022 44740071 45070102 45600110
            46370084 46989968 47249791