MESOSCALE PRECIPITATION DISCUSSION 0086
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
821 PM EDT SAT MAY 31 2014
 
AREAS AFFECTED...SOUTHEAST MT 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 010020Z - 010255Z
 
SUMMARY...A CONGEALING AND RELATIVELY SLOW-MOVING THUNDERSTORM
COMPLEX ACROSS SOUTHEAST MT COULD CAUSE FLASH FLOODING IN AN AREA
OF LOW FLASH FLOOD GUIDANCE VALUES.

DISCUSSION...SATELLITE IMAGERY REVEALS AN INCREASING AREA OF COOL
CLOUD TOPS ACROSS SOUTHEAST MT AS A THUNDERSTORM CLUSTER CONGEALS
ACROSS THE REGION.  SOME BACKBUILDING HAS BEEN NOTED OVER THE PAST
HOUR OR TWO.  THE STORMS ARE FOCUSED BEHIND A SLOW-MOVING
TROUGH/TROWAL. THE 12Z SPC WRF AND 21Z HRRR APPEAR TO HAVE
CAPTURED THIS DEVELOPMENT THE BEST.  PRECIPITABLE WATER VALUES
REMAIN NEAR 1.25", NEAR THE 99TH PERCENTILE FOR THE END OF MAY. 
THE 0-3 KM WIND SHEAR AND CAPE VALUES CURRENTLY REMAIN WITHIN THE
REALM OF WET MULTI-CELL DEVELOPMENT.
  
RADAR IMAGERY REVEALS RAINFALL RATES IN THE 1-2" AN HOUR
RANGE...WHICH SHOULD CONTINUE FOR ANOTHER 2-3 HOURS.  THE
EXPECTATION IS THAT DECREASING CAPE VALUES OVER THE NEXT FEW HOURS
SHOULD LEAD TO A LIMITED PERIOD OF POSSIBLE FLASH FLOODING FOR THE
REGION.  LOCAL AMOUNTS OF 2-3" IN THE MEANTIME COULD LEAD TO FLASH
FLOODING.

ROTH

ATTN...WFO...BIS...UNR...BYZ...GGW...RIW...

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

LAT...LON   47500480 46580402 45240417 44060511 44810688 45650714
            46560695 47550616 47500480