MESOSCALE PRECIPITATION DISCUSSION 0308
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1020 PM EDT SAT JUN 16 2018
AREAS AFFECTED...NORTHERN MINNESOTA
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 170218Z - 170600Z
SUMMARY...CONVECTION HAS BEEN DEVELOPING OVER NORTHWEST MINNESOTA
EARLY THIS EVENING AND TRACKING EASTWARD. GOES EAST IMAGERY
AROUND 02Z SHOWED THE MOST ACTIVE CONVECTION WAS OVER EASTERN
BECKER COUNTY TOWARDAND AND MOVING EASTWARD INTO HUBBARD COUNTY.
THE CHANCES OF FLASH FLOODING INCREASE THROUGH 06Z AS THE STORMS
TRACK ALONG A WELL DEFINED LOW LEVEL THETAE GRADIENT AT H85.
CONTINUED DEVELOPMENT AND EMERGING CELL TRAINING POTENTIAL ALONG
AN EAST TO WEST BOUNDARY AND THETAE GRADIENT OFFERS A THREAT FOR
FLASH FLOODING OVER THE NEXT FEW HOURS.
DISCUSSION...SURFACE OBSERVATIONS INDICATE A WELL-DEFINED MOISTURE
GRADIENT EXTENDING EAST TO WEST ACROSS NORTHERN MN FROM ROUGHLY
FARGO TO SOUTH OF DULUTH. GOES VISIBLE IMAGERY WAS SHOWING
OVERSHOOTING TOPS OVER BECKER COUNTY MN AT 0147Z WHICH WAS IN
CLOSER PROXIMITY TO THE THETAE GRADIENT AND IN A POSITION TO BE
FED DEEPER MOISTURE FROM THE SOUTH PER 00Z SOUNDINGS AND 88D VAD
WIND PROFILERS.
THIS THETA-E AXIS WAS SIMILAR TO THE AXIS OF HEAVIEST RAINFALL
SHOWN BY THE HRAM PROBABILITIES. RAINFALL AMOUNTS OF 1-3 INCHES
ARE POSSIBLE THROUGH 06Z. WITH FLASH FLOOD GUIDANCE WAS GENERALLY
IN THE 1.5 TO 2.5 INCHES PER THREE HOUR RANGE...THE THREAT FOR
FLASH FLOODING WILL BE INCREASING GIVEN A DECENT FEED OF MOISTURE.
FORECAST SOUNDINGS CONTINUE TO SHOW FAVORABLE
IN ADDITION...INDUCED WAVES ALONG THE FRONT WILL FOCUS
STORMS/INFLOW WHILE THE PARALLEL ORIENTATION OF THE FLOW ALOFT TO
THAT OF THE FRONT AND CONVECTION FAVORS A THREAT OF CELL TRAINING
AND REPEAT CELLS OVER TIME.
BANN
ATTN...WFO...DLH...FGF...MPX...
ATTN...RFC...NCRFC...
LAT...LON 47919400 47539257 46999128 46449086 46159242
46199461 46519578 47119604 47899511
Last Updated: 1020 PM EDT SAT JUN 16 2018