MESOSCALE PRECIPITATION DISCUSSION 0476
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1109 AM EDT TUE JUL 19 2016
 
AREAS AFFECTED...CENTRAL AND WESTERN IOWA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 191508Z - 191808Z
 
SUMMARY...NUMEROUS SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER
WESTERN AND CENTRAL IOWA THIS MORNING AND NEW CONVECTION CONTINUES
TO BACK-BUILD BEHIND THE LEADING SQUALL LINE.  HIGHLY MOIST AND
UNSTABLE INFLOW INTO THE DEVELOPING CONVECTION SHOULD SUPPORT
HEAVY RAINFALL RATES WITH 1 TO 3 INCHES OF RAIN POSSIBLE THROUGH
18Z.  

DISCUSSION...RADAR IMAGERY OVER THE PAST HOUR INDICATES MULTIPLE
ROUNDS OF THUNDERSTORM ACTIVITY HAVE DEVELOPED BETWEEN OMAHA AND
DES MOINES.  THE OVERALL FOREWARD PROGRESSION OF THIS NEW MCS IS
ALSO SERVING TO INCREASE RAINFALL AMOUNTS OVER THIS REGION.  THESE
STORMS ARE ALSO FORMING IN A PW MAXIMA OF AROUND 1.9 INCHES, AND
IN A ZONE OF MOISTURE CONVERGENCE WITH MID 70S SURFACE DEWPOINTS
IN THE VICINITY OF A QUASI-STATIONARY FRONT.

THE LATEST HRRR TRIO OF MODELS SUGGESTS THAT THIS CONVECTION WILL
PERSIST OVER THE NEXT FEW MODELS, WITH PATCHY AREAS OF 2+ INCHES
OF RAINFALL.  FLASH FLOOD GUIDANCE VALUES ARE GENERALLY IN THE 1.5
TO 2 INCH RANGE OVER A THREE HOUR PERIOD.  CELL MERGERS WITHIN THE
MCS COULD RESULT IN LOCALIZED FLASH FLOODING.

HAMRICK

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

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

LAT...LON   43479485 43479331 43339236 42479204 41909202 
            41319210 40999243 40859324 41109408 41639498 
            41809604 42289637 42789631 43309570