MESOSCALE PRECIPITATION DISCUSSION 0899
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
857 PM EDT SAT OCT 21 2017

AREAS AFFECTED...SOUTHEAST KS...NORTHEAST OK...WESTERN MO

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 220115Z - 220715Z

SUMMARY...MATURE QLCS MOVING EAST TOWARD LESS RECEPTIVE GROUND
CONDITIONS.  QUICK BURST 1-2" RAINS FOLLOWED BY ADDITIONAL
MODERATE SHIELD PRECIPITATION MAY EXCEED FFG WITH ISOLATED FLASH
FLOODING POSSIBLE

DISCUSSION...GOES-16 10.3UM LOOP AND REGIONAL MRMS RALA IMAGERY
DEPICT A CONSOLIDATING LINEAR CONVECTIVE COMPLEX STRETCHING FROM
HARRISON COUNTY MO (IA STATE LINE) ACROSS KC METRO INTO NORTH
CENTRAL OK ALONG/JUST AHEAD OF COLD FRONT. MEAN CLOUD BEARING FLOW
REMAINS FAIRLY PARALLEL TO THE FRONTAL ZONE ALLOWING FOR SOME
CROSS TRACKS OF UPDRAFT/DOWNDRAFT CORES THOUGH WITH GREATER
EASTWARD EXPANSION OF HEIGHT FALLS...THICKNESS FIELDS ARE
TIGHTENING SLIGHTLY SUGGESTING A BIT MORE INCREASED EASTWARD
PROPAGATION THAN CURRENTLY OBSERVED.  STILL STRENGTHENING
LLJ/MOISTURE FLUX STARTING TO TAP EVEN FURTHER DEEPER GULF STREAM
MOISTURE (CIRA TPW/LPW ANALYSIS SHOWS STRONG CHANNEL ACROSS LA/AR
TOWARD SW MO) AND BY 04Z RAP FORECASTS DEPICT A BROAD PLUME OF
1.5+" TPWS ALONG 50+ KT INFLOW TO THE LINE (THOUGH BECOMING LESS
ORTHOGONAL WITH TIME).  ALL CONSIDERED THE MAIN CORES ARE LIKELY
TO PRODUCE 1-1.5" IN 15-30 MINUTES WITH SQUALL PASSAGE...ALREADY
VERY CLOSE TO 1HR FFG VALUES IN THE AREA.  STRONGER ISOLATED
INCIDENTS ALONG THE QLCS MAY BE ENHANCED TO 2" BUT WOULD BE HIGHLY
LOCALIZED.  AS SUCH FF IS POSSIBLE PARTICULARLY IN URBAN CENTERS.

GOES 3-CHANNEL WV SUITE AND AMVS DEPICT STEADILY INCREASING
NORTHERLY EVACUATION OUTFLOW AS JET ENERGY ROUNDS THE BASE OF THE
TROF AND ZIPS NORTHWARD.  GIVEN ORIENTATION OF THE JET IS WEST OF
THE QLCS DEPICTED BY -70C IR TOPS...STRONG MST ASCENT THROUGH THE
SQUALL LINE INTO THE RIGHT ENTRANCE REGION OF THE EXPANDING JET
STREAK WILL ALLOW FOR MODEST RAINFALL EFFICIENCY WITH HOURLY RATES
OF .5-.75"/HR PSBL AFTER THE MAIN SQUALL LINE FOR 2 TO 3 HOURS
ADDING A POTENTIAL 1-2 ADDITIONAL INCHES LEADING TO THE
POSSIBILITY OF LOCALIZED MAX NEAR 4" IN LINE WITH HI-RES CAMS SUCH
AS THE ESRL HRRRV3/ARW2/NSSL-WRF. THIS WOULD EXCEED 3HR FFG ACROSS
THE AREA. HRRR/HRRRV3 BASELINE SOIL SATURATION OF UP TO 50% IN TOP
CM (MAINLY FROM LAST WEEKEND'S RAINFALL EVENT ACROSS SE KS TO
CENTRAL MO) WOULD LIKELY EXPERIENCE THE GREATEST RISK FOR
INCREASED RUNOFF AND FLOODING CONCERNS. 

GALLINA

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

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

LAT...LON   39979316 39259207 38459238 37299329 36479422
            36209486 36119580 36149696 36539726 38299550
            39779403