MESOSCALE PRECIPITATION DISCUSSION 0453
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
204 PM EDT MON JUL 11 2016
 
AREAS AFFECTED...CENTRAL MN...SOUTHEAST ND...NORTHEAST SD 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 111800Z - 112300Z
 
SUMMARY...INCREASING CONVECTIVE COVERAGE MAY LEAD TO A FLASH FLOOD
THREAT THIS AFTERNOON.

DISCUSSION...AS OF 18Z SURFACE LOW PRESSURE IS SITUATED ACROSS
CENTRAL SD...WITH A WARM FRONT EXTENDING EAST INTO SOUTHERN MN.
MOST OF THE HIGH RES GUIDANCE HAVE BEEN PLAYING CATCH UP ALL
DAY...AS THEY WERE ALL TOO FAR NORTH WITH THE SURFACE FRONT
POSITION. CONVECTION HAS BEEN FOCUSING ALONG AN ELEVATED BOUNDARY
FROM NEAR THE ND/SD BORDER EAST INTO CENTRAL MN. GUIDANCE APPEARS
TO BE TOO FAR NORTH WITH THIS FEATURE AS WELL. 800 TO 700 MB WINDS
ARE INCREASING ACROSS THE REGION EARLY THIS AFTERNOON AHEAD OF A
TROUGH EXTENDING OUT FROM THE UPPER LOW CURRENTLY OVER MT. AS THIS
INCREASED FLOW INTERACTS WITH THE MOISTURE PLUME OVER THE EASTERN
PLAINS...EXPECT LOW LEVEL MOISTURE TRANSPORT TO SIGNIFICANTLY
INCREASE INTO THE STALLED OUT ELEVATED FRONTAL BOUNDARY. THIS IS
EXPECTED TO RESULT IN INCREASED CONVECTIVE COVERAGE OVER THE NEXT
SEVERAL HOURS FROM NEAR THE SD/ND BORDER EASTWARD INTO CENTRAL MN.

STEEP MID LEVEL LAPSE RATES ARE BEING ADVECTED INTO THE AREA FROM
THE SOUTH...ALLOWING FOR THE MAINTENANCE OF 1000 TO 2000 J/KG OF
MUCAPE ALONG THE ELEVATED BOUNDARY. PRECIPITABLE WATER CONTINUES
TO INCREASE ACROSS THE AREA AS WELL...WITH VALUES APPROACHING OR
SURPASSING 2" IN SPOTS. STORMS HAVE BEEN AND SHOULD GENERALLY
CONTINUE TO BE PROGRESSIVE. HOWEVER STORM MOTIONS SHOULD CONTINUE
TO EXHIBIT A LARGE COMPONENT PARALLEL TO THE ELEVATED
BOUNDARY...ALLOWING FOR TRAINING TO OCCUR. WHILE THE PROGRESSIVE
NATURE OF THE STORMS SHOULD GENERALLY KEEP AMOUNTS IN THE 1-2" PER
HOUR RANGE...THE EXPECTED INCREASE IN STORM COVERAGE AND TRAINING
COULD RESULT IN ADDITIONAL RAINFALL AS HIGH AS 2-5" ACROSS THE MPD
AREA. THIS COMBINED WITH WHAT HAS ALREADY FALLEN IS EXPECTED TO
LEAD TO AT LEAST A SCATTERED FLASH FLOOD RISK AS WE HEAD THROUGH
THE AFTERNOON HOURS.

RECENT RUNS OF THE PARALLEL HRRR SHOW SOME IMPRESSIVE AMOUNTS
ACROSS PORTIONS OF CENTRAL MN. AS MENTIONED ABOVE...THE AXIS IS
LIKELY TOO FAR NORTH IN THE MODEL...BUT A SOUTHWARD SHIFTED 16Z
HRRR PARALLEL SEEMS PLAUSIBLE. WHILE PROBABLY TOO HIGH WITH THE
MAGNITUDE OF AMOUNTS...THE AXIS SHOWN BY THE 12Z NSSL WRF SEEMS TO
BE THE BEST MATCH TO OUR EXPECTED EVOLUTION.

CHENARD

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

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

LAT...LON   46979546 46859359 46779239 46529213 46069243 
            45729296 45659379 45539712 45789773 46469794 
            46909739