MESOSCALE PRECIPITATION DISCUSSION 0477
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
224 PM EDT TUE JUL 19 2016
 
AREAS AFFECTED...SOUTHERN IOWA...NORTHERN MO...WESTERN IL 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 191823Z - 192123Z
 
SUMMARY...A COMPLEX OF THUNDERSTORMS CONTINUES OVER IOWA EARLY
THIS AFTERNOON AND NEW CONVECTION CONTINUES TO TRAIN OVER MANY OF
THE SAME AREAS.  A VERY HUMID AND UNSTABLE INFLOW INTO THE
CONVECTIVE COMPLEX SHOULD SUPPORT HEAVY RAINFALL RATES WITH 1 TO 3
INCHES OF RAIN POSSIBLE THROUGH 21Z, WITH ISOLATED HIGHER AMOUNTS.

DISCUSSION...RADAR IMAGERY OVER THE PAST FEW HOURS INDICATES
MULTIPLE ROUNDS OF THUNDERSTORM ACTIVITY OVER SOUTH CENTRAL IOWA. 
THE OVERALL FOREWARD PROGRESSION OF THIS MCS IS SLOW TOWARDS THE
SOUTHEAST.  THESE STORMS ARE ALSO FORMING IN A PW MAXIMA OF AROUND
2 INCHES, AND IN A ZONE OF MOISTURE CONVERGENCE WITH MID 70S
SURFACE DEWPOINTS IN THE VICINITY OF A QUASI-STATIONARY FRONT
DRAPED ACROSS SOUTHERN IOWA AND WESTERN ILLINOIS.  A DEEP
WARM-CLOUD LAYER ALSO EXISTS AND THUS INCREASES THE PRECIPITATION
EFFICIENCY.

THE LATEST HRRR MODELS SUGGEST THAT THIS CONVECTION WILL PERSIST
OVER THE NEXT FEW MODELS, BUT THE PLACEMENT OF THE RAINFALL
APPEARS TO BE DISPLACED TOO FAR NORTH BASED ON THE LATEST RADAR
TRENDS.  FLASH FLOOD GUIDANCE VALUES ARE LOWEST IN SOUTHWESTERN
IOWA DUE TO RECENT HEAVY RAINFALL.  CELL MERGERS WITHIN THE MCS
COULD RESULT IN LOCALIZED FLASH FLOODING.

HAMRICK

ATTN...WFO...DMX...DVN...EAX...FSD...ILX...LSX...OAX...

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

LAT...LON   42289509 42159396 41649229 41219052 40708966 
            39658928 39078984 39269113 39689313 39909499 
            40459584 41639610 42159580