MESOSCALE PRECIPITATION DISCUSSION 0327
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1133 PM EDT THU JUN 09 2016
 
AREAS AFFECTED...PORTIONS OF ND 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 100332Z - 100832Z
 
SUMMARY...AN EVOLVING MCS COULD EXHIBIT CELL MERGERS/SHOW PERIODS
OF CELL TRAINING OVER THE NEXT SEVERAL HOURS.  WITH HOURLY RAIN
RATES UP TO 2", FLASH FLOODING IS POSSIBLE.

DISCUSSION...A STATIONARY FRONT IS ACTING AS THE FOCUS FOR NEW
CONVECTION ACROSS SOUTHWEST SD, IN ADVANCE OF A PROGRESSIVE
SHORTWAVE ACROSS MT.  PRECIPITABLE WATER VALUES OF 1.1" --
CORRECTED TO ~1.3" FOR SEA LEVEL -- EXIST IN THIS AREA.  INFLOW AT
850 HPA IS 25 KTS PER VAD WIND PROFILES.  MUCAPES TO THE IMMEDIATE
SOUTH OF THE GROWING, CONGEALING COMPLEX ARE 2000-3000 J/KG. 
TEMPERATURES ALOFT ARE FAIRLY WARM, WITH RAP FORECASTS SHOWING
9-12C TEMPERATURES AT 700 HPA.

FLASH FLOOD GUIDANCE VALUES AHEAD OF THE CLUSTER IS NOT OVERLY
HIGH, ELEVATING THE RISK FOR EXCESSIVE RAINFALL.  RAP FORECASTS
INDICATE PRECIPITABLE WATER VALUES COULD RISE ABOVE 1.75" AS THE
CLUSTER MOVES OVER THE TOP OF A POOL OF 6000+ J/KG MUCAPE.  WHILE
INFLOW IS EXPECTED TO SLIGHTLY DECREASE OVERNIGHT, IT SHOULD
REMAIN SUFFICIENT FOR ORGANIZED CONVECTION.  HOWEVER, WITH THE
WARM TEMPERATURES AT 700 HPA, THERE IS A RISK THAT THIS COMPLEX
COULD WEAKEN AS IT MOVES OUT OF THE HIGH PLAINS.  THE EXPECTATION
IS THAT THE SIGNIFICANT INSTABILITY IN SD WOULD ALLOW TO COMPLEX
TO PERSIST OVER THE NEXT SEVERAL HOURS.  WITH TIME, THE COMPLEX
COULD WINNOW INTO A NARROWING BAND AS A COLD POOL TO THE WEST
HELPS FOCUS THE CONVECTION.  FORWARD PROPAGATING CONVECTIVE
VECTORS SUGGEST THE ACTIVITY COULD MOVE EAST AS FAST AS 40 KTS. 
IN THE MEANTIME, CELL MERGERS WITH SHORT PERIODS OF TRAINING COULD
LEAD TO HOURLY RAIN RATES UP TO 2", WITH LOCAL AMOUNTS OF 2-4". 
IN GENERAL, THE MESOSCALE/CAM GUIDANCE APPEARS LIGHT, OR TOO FAR
NORTH IN PLACEMENT, WITH THIS CONVECTIVE AREA.  A SOUTHWARD
ADJUSTED 00Z NAM CONEST APPEARS CLOSEST TO REALITY.  

ROTH

ATTN...WFO...BIS...FGF...GGW...

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

LAT...LON   49019716 47769733 46489876 46410250 46930472 
            48100343 48910182