MESOSCALE PRECIPITATION DISCUSSION 0282
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
832 PM EDT SAT AUG 16 2014
 
AREAS AFFECTED...SOUTHEAST ND...EXTREME WEST-CENTRAL MN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 170030Z - 170600Z
 
SUMMARY...VERY SLOW-MOVING SHOWERS AND THUNDERSTORMS CONTINUE
ACROSS SOUTHEAST ND AND WILL PERSIST THROUGH THE EVENING HOURS.
ADDITIONAL FLASH FLOODING WILL BE LIKELY.

DISCUSSION...A WELL-DEFINED SURFACE LOW CENTER AND ACCOMPANYING
MID LVL VORT CENTER OVER S CNTRL ND IS EXPECTED GRADUALLY WEAKEN
OVERNIGHT...ALTHOUGH IT WILL CONTINUE TO INTERACT WITH A RATHER
MOIST/UNSTABLE BNDRY LYR OVER SERN ND AND PORTIONS OF NERN SD AND
W CNTRL MN. 

THE LATEST GOES-SOUNDER AND GPS DATA INDICATE A POOL OF 1.75 INCH
PWATS OVER THIS AREA...AND THIS IS HELPING TO CONTRIBUTE TO
PERSISTENTLY HVY RAINFALL RATES WHERE COLD-TOPPED CONVECTION HAS
CONTINUED TO DEVELOP AND REPEAT OVER OR NEAR THE SAME AREAS.

THE 22Z HRRR AND TO LESSER EXTENTS THE 12Z ARW AND 12Z NMMB SHOW
SIGNALS FOR CONCENTRATED BUT SIGNIFICANT RAINFALL BETWEEN 00Z AND
06Z OVER ESP SERN ND AS CONVECTION REMAINS ORGANIZED IN LIEU OF A
COMPACT BUT STRONG VORT CENTER AT LEAST FOR THE TIME BEING. EVEN
THE 12Z GEM-REGIONAL WHICH IS TOO FAR NORTH WITH ITS CONVECTIVE
MAX...INDICATES A SIGNAL FOR VERY HVY AMTS. BY LATER IN THE
EVENING AND ESP PAST 06Z...THE VORT ENERGY SHOULD BEGIN TO WEAKEN
AND THE CONVECTION SHOULD TEND TO BECOME LESS ORGANIZED BY THAT
TIME.

GIVEN INTENSE RAINFALL RATES UP TO 2 INCHES/HR AND THE
SLOW-MOVEMENT...ADDITIONAL FLASH FLOODING IS EXPECTED THROUGH THE
EVENING HOURS WITH POTENTIAL FOR SEVERAL MORE INCHES OF RAIN
LEADING UP TO MIDNIGHT. WILL CONTINUE TO MONITOR.

ORRISON

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

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

LAT...LON   47249799 47239709 47029602 46549505 46019469 45849491
            45749572 45909682 45929770 46009850 46329921 46739941
            47129876 47249799