MESOSCALE PRECIPITATION DISCUSSION 0581
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
640 PM EDT FRI AUG 19 2016
 
AREAS AFFECTED...MID-MISSOURI VALLEY INTO IOWA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 192239Z - 200400Z
 
SUMMARY...SLOW MOVING STORMS FROM THE MID-MISSOURI VALLEY INTO IA
WILL POSE A LOCALIZED FLASH FLOOD THREAT OVER THE NEXT SEVERAL
HOURS. WHILE COVERAGE SHOULD BE LIMITED...A FEW LOCATIONS COULD
PICK UP 3-4 INCHES WHICH COULD FALL QUICKLY.

DISCUSSION...22Z SURFACE ANALYSIS SHOWED A QUASI-STATIONARY FRONT
EXTENDING SWWD THROUGH WI INTO A SURFACE LOW IN W-CNTRL IA...AND
SWWD INTO CNTRL KS. MLCAPE IS ESTIMATED TO BE 1500-2500 J/KG VIA
THE LATEST SPC MESOANALYSIS AND ONGOING CONVECTION WAS OBSERVED
FROM THE MISSOURI RIVER INTO THE N-CNTRL PORTION OF IA WITH
OBSERVED RAINFALL RATES OF 1-2 IN/HR. 

MOVEMENT OF THE FRONTAL BOUNDARY IS EXPECTED TO BE SLOW OVER THE
NEXT SEVERAL HOURS. AN EWD MOVING VORTICITY MAX IN KS...OBSERVED
ON VISIBLE SATELLITE IMAGERY...SHOULD DELAY THE SEWD PUSH OF THE
FRONT IN SWRN IA...DESPITE THE PROGRESSIVE NATURE OF A LARGER
SCALE UPPER TROUGH MOVING ACROSS THE NRN PLAINS. TOTAL MOISTURE
OVER IA IS NOT EXPECTED TO INCREASE MUCH BEFORE 06Z...BEFORE
STRENGTHENING LOW LEVEL FLOW AHEAD OF AN ADVANCING 850 MB WAVE
INCREASES MOISTURE TRANSPORT FROM THE SW. HOWEVER...AMPLE
INSTABILITY IS EXPECTED TO BE TAPPED OVER THE NEXT FEW
HOURS...WITH RELATIVELY SLOW STORM MOTIONS AND CELL MERGERS
LEADING TO POCKETS OF HEAVY RAINFALL IN EXCESS OF 3 INCHES IN A
FEW LOCATIONS. GIVEN CURRENT FLASH FLOOD GUIDANCE OF 2-3 INCHES IN
3 HOURS...A FEW FLASH FLOOD ISSUES COULD BE SEEN THROUGH 04Z.

OTTO

ATTN...WFO...ARX...DMX...DVN...EAX...FSD...OAX...TOP...

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

LAT...LON   43129162 42699077 41489180 40199430 39799558 
            40159649 40879684 41969658 42469562 42939375