MESOSCALE PRECIPITATION DISCUSSION 0314
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
815 AM EDT SAT AUG 23 2014
 
AREAS AFFECTED...FAR NERN MISSOURI....ERN IOWA TO JUST ACROSS THE
MISSISSIPPI RIVER 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 231212Z - 231530Z
 
SUMMARY...THE POTENTIAL FOR 2-3 IN/HR RAINFALL RATES WITH FLASH
FLOODING SHOULD CONTINUE ACROSS ERN IOWA UNTIL ABOUT 15Z WHEN LOW
LEVEL INFLOW DIMINISHES TO LESS THAN 20 KTS.

DISCUSSION...A VERY COLD TOPPED MCS WITH IR SATELLITE MEASURING
COLDER THAN -80 C CONTINUES TO PROGRESS ACROSS CNTRL IOWA EARLY
THIS MORNING WITH PW VALUES NEAR OR IN EXCESS OF 2 INCHES.
CONVECTION CONTINUES TO FORM AT THE NOSE OF A 30-40 KT LOW LEVEL
JET STRETCHING NEWD ACROSS KANSAS AND MISSOURI AND WHILE THE MAIN
ARC OF CONVECTION HAS BEEN STEADILY PROGRESSING EASTWARD...WARM
ADVECTION DRIVEN CONVECTION HAS DEVELOPED JUST AHEAD OF THE LINE
ACROSS SERN IOWA. A RECENT IOWA MESONET REPORT OF 2.4 INCHES IN
ONE HOUR WAS REPORTED AT 11Z IN CLARKE COUNTY WHICH IS
REPRESENTATIVE OF THE EXTREMELY MOIST ENVIRONMENT.

WHILE HI-RES MODEL QPF HAS REALLY STRUGGLED WITH THIS
EVENT...OTHER FIELDS APPEAR USABLE. RECENT RAP AND HRRR RUNS
SUGGEST A LOW LEVEL JET OF ABOUT 30 KTS JUST AHEAD OF AN MCV
LOCATED JUST SE OF DSM WILL PERSIST FOR ANOTHER FEW
HOURS...EXCEEDING INDIVIDUAL STORM MOTION MEAN FLOW TO THE
NORTHEAST OF ABOUT 20 KTS. THIS WILL SUPPORT THE SHORT TERM
POTENTIAL FOR TRAINING AND ADDITIONAL HEAVY RAINFALL TOTALS UP TO
3-5 INCHES BY 15Z. 

OTTO

ATTN...WFO...MKX...LSX...DVN...ARX...DMX...EAX...

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

LAT...LON   42569037 41519019 40039142 40029285 40459330 40879334
            41619322 43039310 43419160 42569037