MESOSCALE PRECIPITATION DISCUSSION 0179
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
430 PM EDT SAT JUN 06 2015
 
AREAS AFFECTED......EASTERN NE/SOUTHEAST SD/SOUTHWEST MN/WESTERN
IA... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 062030Z - 070200Z
 
SUMMARY...A DEVELOPING MCS PRODUCING VERY HEAVY RAINFALL COULD
RESULT IN FLASH FLOODING.

DISCUSSION...CONVECTION IS BEGINNING TO DEVELOP OVER WESTERN
IA...EAST OF THE FRONTAL BOUNDARY EXTENDING FROM EASTERN SD
THROUGH EASTERN NE...IN AN AREA OF MLCAPE VALUES BETWEEN 2500 AND
3500 J/KG. A STRENGTHENING 25 TO 35 KNOT LOW LEVEL JET TRANSPORTS
1.75 INCH PRECIPITABLE WATER AIR UP ALONG THE FRONT. AS A SHORT
WAVE TRACKS FROM WY/CO THROUGH THE SD/MN THIS EVENING... THE AREAL
EXTENT OF THE CONVECTION IS EXPECTED TO INCREASE.

THERE IS A STRONG HIGH RESOLUTION MODEL SIGNAL THAT AN MCS
DEVELOPS OVER SOUTHEAST SD/NORTHEAST NE BEFORE 00Z...WHICH THEN
TRACKS ACROSS NORTHWEST IA THROUGH 02Z. GIVEN THE INSTABILITY AND
HIGH MOISTURE CONTENT AIR IN PLACE...LOCAL 2 TO 4 INCH RAINFALL
AMOUNTS ARE POSSIBLE...ESPECIALLY IF BACKBUILDING OCCURS BETWEEN
00-02Z (WHICH IS SUGGESTED BY THE NAM SIMULATED SATELLITE IMAGERY
OVER NORTHWEST IA). THESE AMOUNTS ARE SUPPORTED BY THE LATEST
EXPERIMENTAL HRRR...AS WELL AS THE 12Z NSSL WRF AND 12Z WRF ARW.

THE THREAT FOR FLASH FLOODING COULD EXTEND BEYOND 02Z ACROSS
PORTIONS OF NORTHEAST NE/WESTERN IA...AS THE MCS TRACKS SOUTHEAST.
IF THIS OCCURS...ANOTHER MPD WOULD BE ISSUED THIS EVENING TO
EXPAND THE FLASH FLOOD THREAT.

HAYES

ATTN...WFO...DMX...FSD...LBF...MPX...OAX...

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

LAT...LON   44539775 44539772 43889859 42599833 41859604 
            42299335 43539378 44509579