MESOSCALE PRECIPITATION DISCUSSION 0485
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
156 PM EDT TUE SEP 08 2015
 
AREAS AFFECTED...NERN OK...SERN KS...SWRN MO...NWRN AR 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 081754Z - 082300Z
 
SUMMARY...THE COVERAGE OF FLASH FLOOD PRODUCING RAINFALL WILL
LIKELY INCREASE THROUGH THE EARLY AFTERNOON ACROSS PORTIONS OF
NERN OKLAHOMA...SERN KANSAS INTO THE OZARKS OF MISSOURI/ARKANSAS.
TRAINING WITH RAINFALL RATES OF 1-2 IN/HR CAN BE EXPECTED WITH 6
HOUR RAINFALL UP TO 4-5 INCHES POSSIBLE.

DISCUSSION...AN EXTENDED PLUME OF DEEP MOISTURE...PRECIPITABLE
WATER VALUES RANGING BETWEEN 1.9 AND 2.1 INCHES...STRETCHED ACROSS
THE SRN AND CNTRL PLAINS...ACROSS THE MPD THREAT AREA...INTO THE
MIDWEST. AS REFERENCED IN 1649Z SPENES...THERE WAS A CLEAR
CONNECTION OF THIS MOISTURE PRESENT IN THE MID-UPPER LEVELS TO
HURRICANE LINDA LOCATED IN THE ERN PACIFIC. THIS COMBINED WITH WET
BULB ZERO LEVELS NEAR 14 KFT...PER 12Z SGF RAOB...IS HELPING TO
CONTRIBUTE TO EFFICIENT RAINFALL RATES. 

CONFLUENT FLOW WAS OBSERVED IN RECENT VAD WIND PROFILE PLOTS
BETWEEN 850-700 MB...WHICH IS FORECAST TO WEAKEN NEAR 850 MB PER
RECENT RAP FORECAST GUIDANCE. HOWEVER...THE 700 MB PORTION IS
EXPECTED TO CONTINUE INTO THE AFTERNOON AND VISIBLE SATELLITE
IMAGERY SHOWS MOSTLY CLEAR SKIES SOUTHWEST OF AN OUTFLOW BOUNDARY
LOCATED IN SWRN MISSOURI AT 17Z...HELPING TO INCREASE INSTABILITY.
LOW LEVEL SWLY FLOW...ALBEIT WEAK...SHOULD PERSIST...CONTINUING TO
OVERRUN THE OUTFLOW BOUNDARY IN THE SHORT TERM LEADING TO PERIODS
OF TRAINING WITH RAIN RATES OF 1-2 IN/HR. MEANWHILE...THE MPD
THREAT AREA IS LOCATED BENEATH THE EDGE OF THE SYNOPTIC SCALE
UPPER TROUGH AXIS HELPING TO CREATE DIFFLUENT FLOW ALOFT WHICH IS
EXPECTED TO HELP MAKE UP FOR WEAKER LOW LEVEL CONVERGENCE. 

RECENT 12Z HI-RES MODEL GUIDANCE HAS THIS AREA HIGHLIGHTED FOR
HEAVY RAIN THROUGHOUT THE REMAINDER OF THE DAYLIGHT HOURS...WITH
DIFFERING TIMING...BUT THE 12Z NSSL WRF AND RECENT RUNS OF THE
OPERATIONAL HRRR APPEAR TO HAVE THE BEST HANDLE BASED ON
OBSERVATIONS THROUGH 17Z. 

OTTO

ATTN...WFO...EAX...ICT...LZK...OUN...SGF...TOP...TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...

LAT...LON   38059494 37699338 37549181 36849170 36129313 
            35949536 36399698 37139741 37749695 37959616