MESOSCALE PRECIPITATION DISCUSSION 0482
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
156 AM EDT MON SEP 07 2015
 
AREAS AFFECTED...VICINITY OF THE MO/IA BORDER 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 070556Z - 070856Z
 
SUMMARY...THUNDERSTORMS ARE ATTEMPTING TO LENGTHEN INTO A BAND
ACROSS SOUTHWEST IA.  HOURLY RAIN RATES UP TO 2" COULD CAUSE FLASH
FLOODING.

DISCUSSION...AS AN OUTFLOW BOUNDARY HAS BEEN SHIFTING SOUTHWARD
THROUGH IA AND NORTHEAST KS, CONVECTION TO ITS NORTH HAS BEEN
FOLLOWING SUIT AT ROUGHLY 10 KTS SINCE 00Z.  INDIVIDUAL CELL
MOTION TO THE EAST AT ~30 KTS HAS BEEN OBSERVED BY RADAR IMAGERY,
WHICH IS CAUSING CELL TRAINING.  PRECIPITABLE WATER VALUES OF 1.9"
ARE AVAILABLE PER GPS INFORMATION.  INFLOW AT 850 HPA OF 25-30 KTS
OUT OF THE SOUTHWEST IS IMPORTING 1000+ J/KG MUCAPE OVER THE
OUTFLOW BOUNDARY.

THE MESOSCALE QPF GUIDANCE APPEARS TOO FAR TO THE NORTH WITH THIS
ACTIVITY, THOUGH IT DOES ADVERTISE LOCAL AMOUNTS IN THE 2-4" RANGE
OVER THE NEXT SEVERAL HOURS WHICH COULD FALL QUICKLY.   RAIN RATES
UP TO 2" ARE POSSIBLE PER THE AVAILABLE MOISTURE DUE TO CELL
TRAINING.  STORMS SHOULD CONTINUE DROPPING SLOWLY SOUTHWARD WITH
THE OUTFLOW BOUNDARY WITH TIME.  THE AVAILABLE INSTABILITY
SUGGESTS ANOTHER FEW HOURS OF ISSUES, SO CHOSE A THREE HOUR
HORIZON.  HIGHER FLASH FLOOD GUIDANCE VALUES IN THIS REGION KEPT
THE CATEGORY AS POSSIBLE.

ROTH

ATTN...WFO...DMX...EAX...OAX...

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

LAT...LON   41349415 41149291 40349275 39979388 40129633 
            40649676 41259612