MESOSCALE PRECIPITATION DISCUSSION 0674
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
332 PM EDT FRI SEP 16 2016
 
AREAS AFFECTED...MO...SRN IL...SE KS...NE OK...NW AR 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 161931Z - 162331Z
 
SUMMARY...SLOWLY TRAINING CONVECTION PRODUCING HEAVY RAIN HAD
ALREADY PROMPTED FLASH FLOOD WARNINGS. A FAVORABLY TIMED UPSTREAM
SHORTWAVE WILL SUSTAIN SCATTERED TO NUMEROUS STORMS THROUGH EARLY
EVENING...LEADING TO NEW AND POSSIBLY INTENSIFYING FLASH FLOODING.

DISCUSSION...AT 19Z THE RADAR CHARACTER AND BEHAVIOR OF CONVECTION
ACROSS MISSOURI AND ADJACENT STATES WAS CONCERNING. ONE FLASH
FLOOD WARNING WAS ALREADY PROMPTED ALONG INTERSTATE 44 IN CENTRAL
MO...AND THE STEADY GROWTH OF CELLS UPSTREAM WAS INDICATIVE OF A
700 MB SHORTWAVE SLIDING THROUGH EASTERN OK/KS. THIS WAVE WAS
CO-LOCATED WITH ENHANCED DIFLUENCE AHEAD OF HIGHER LEVEL
TROUGHING. THE SYNOPTICS...IN ADDITION TO FAVORABLE INSTABILITY IN
AN UNCAPPED ENVIRONMENT ACROSS THE OZARKS...WILL LEAD TO AN ACTIVE
SEVERAL HOUR PERIOD IN KS/OK/MO...WITH NARROW DOWNSTREAM EXTENSION
INTO IL PER VISIBLE IMAGERY. CELLS HAD EXHIBITED SOME ROTATION
WITHIN AN ENVIRONMENT MARKED BY MODERATE DEEP LAYER SHEAR...AND
THIS WILL ASSIST THE LONGEVITY OF INDIVIDUAL CELLS. THE MOTION OF
MATURE CELLS...HOWEVER...WAS GENERALLY FOLLOWING THE MEAN
WIND...WHICH WAS PARALLEL TO THE OUTFLOW BOUNDARY THAT HAD DROPPED
INTO THE REGION EARLIER TODAY. THIS SCENARIO SUGGESTS ADDITIONAL
SW TO NE TRAINING OF CONVECTION...AND WITH RADAR-DERIVED RAIN
RATES OF AT LEAST 1.5 INCHES PER HOUR IT WOULD SEEM THAT
ADDITIONAL OR INTENSIFIED FLASH FLOODING IS LIKELY IN SOME
LOCATIONS.

IN THE NEAR TERM...WE NOTED A DIP IN REFLECTIVITY OWING TO
ATTENUATION OF THE KSGF DUAL POL DUE TO LOSS OF POWER IN THE
VERTICAL BEAM HAS RAIN RUNS DOWN THE RADOME. SUSPECT THE CURRENT
TRUTH IS CLOSER TO WHAT WAS OBSERVED AT 1904 Z...WITH WIDESPREAD
45-50 DBZ AND GREATER COVERAGE OF HEAVY RAIN HYDRO CLASS.

BURKE

ATTN...WFO...ICT...LSX...LZK...PAH...SGF...TSA...

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

LAT...LON   38468932 38028885 37418946 36989085 36599261 
            36019446 36319552 37389516 38079336 38399109