MESOSCALE PRECIPITATION DISCUSSION 0395
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
730 PM EDT TUE JUL 28 2015
 
AREAS AFFECTED...MID MISSOURI VALLEY INTO SRN IOWA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 282329Z - 290500Z
 
SUMMARY...RAINFALL RATES OF 1-2 IN/HR WILL PRODUCE A BRIEF THREAT
FOR FLASH FLOODING ACROSS A REGION OF LOWER FFG ACROSS THE
MID-MISSOURI VALLEY INTO SRN IOWA. THE THREAT WILL BE BRIEF
HOWEVER...AS A PROGRESSIVE COLD FRONT WILL SWEEP THROUGH THE
REGION BY 06Z. 

DISCUSSION...AT 23Z...RADAR IMAGERY FROM KDMX SHOWED A CLUSTER OF
CONVECTION JUST SOUTHEAST OF DSM...MOVING OFF TOWARD THE EAST AT
ABOUT 25 KTS WHILE ADDITIONAL SHOWERS WERE DEVELOPING OVER SWRN
IOWA. THE ACTIVITY WAS OCCURRING JUST NORTH OF A WELL DEFINED
OUTFLOW BOUNDARY EXTENDING WEST-EAST ACROSS WRN IOWA...WITH MLCAPE
ESTIMATED TO BE BETWEEN 2000-4000 J/KG ALONG AND SOUTH OF THE
BOUNDARY ACCORDING TO RECENT SPC MESOANALYSIS PAGE. PRECIPITABLE
WATER VALUES ARE ESTIMATED TO BE BETWEEN 1.75 AND 2.00 INCHES JUST
AHEAD OF A PROGRESSIVE COLD FRONT MOVING ACROSS W-CNTRL IOWA.
TRENDS IN VISIBLE IMAGERY HAVE ALSO SHOWN AN INCREASE IN CUMULUS
DEVELOPMENT WITH A FEW THUNDERSTORMS DEVELOPING ALONG THE COLD
FRONT IN NRN KANSAS WHERE CIN HAS ERODED OVER THE PAST SEVERAL
HOURS.

GIVEN THE MOISTURE IN PLACE...HEAVY RAINFALL RATES OF 1-2 IN/HR
ARE EXPECTED WITH CONVECTION AHEAD OF THE COLD FRONT OVER THE NEXT
FEW HOURS AS THUNDERSTORMS CONTINUE TO DEVELOP. CONTINUED
OVERRUNNING OF THE OUTFLOW BOUNDARY IS ALSO EXPECTED WHICH MAY
ALLOW FOR THE GREATEST HEAVY RAIN POTENTIAL ACROSS SRN IOWA. GIVEN
FLASH FLOOD GUIDANCE IS ONLY 1-2 IN/HR ACROSS MOST OF THE MPD
THREAT AREA...A BRIEF THREAT FOR FLASH FLOODING IS
EXPECTED...MOSTLY WHERE TEMPORARY CELL TRAINING DEVELOPS. RECENT
RUNS OF THE HRRR AND EXPERIMENTAL HRRR HAVE BEEN DOING THE BEST SO
FAR AND SUPPORT THE POTENTIAL FOR A FEW 2-3 INCH MAXIMA FROM
S-CNTRL IOWA TO THE MISSOURI BORDER THROUGH 05Z. 

OTTO

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

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

LAT...LON   42679031 42258989 41509038 40619249 39769459 
            39489587 39689635 40049627 41029536 41539472 
            42059342 42529154