MESOSCALE PRECIPITATION DISCUSSION 0274
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
130 PM EDT SAT MAY 27 2017

AREAS AFFECTED...SOUTHERN MISSOURI...EXT NORTHEAST AR...EXT
SOUTHEASTERN KS

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

VALID 271730Z - 272200Z

SUMMARY...COMPLEX EVOLUTION/MULTIPLE SWATHS OF HEAVY RAINFALL AND
TRAINING MAY POSE FLASH FLOODING CONCERN THIS AFTERNOON IN MO.

DISCUSSION...GOES-16 MESO LOOPS DENOTE A COMPLEX BOUNDARY
SITUATION ACROSS THE CENTRAL MO RIVER VALLEY AND OZARKS.  AN
INITIAL GRAVITY WAVE/LEAD EDGE OF AN UNDULAR BORE HAS ROLLED
THROUGH MO IN AN ARC FROM ONGOING MCV IN IA ACROSS CENTRAL MO AND
TRAILING BACK SOUTH OF I-44 ACROSS S MO INTO NE OK.  MAXIMIZED
CONVERGENCE AT AN INFLECTION ON THE ARC WITH SUFFICIENT DEEP WAA
HAS ACTIVATED CONVECTION IN CENTRAL MO NEAR AIZ/TBN HAS EXPANDED
EASTWARD ENOUGH ALONG THE STATIONARY/RETURNING WARM FRONT...THAT
IS GENERALLY ORIENTED WELL WITH THE MEAN FLOW TO SUPPORT SOME
TRAINING IN THE SHORT-TERM. THIS AREA IS LIKELY TO FALL VICTIM TO
BEING CUT-OFF AS SFC/NEAR SFC ROOTED CONVECTION DEVELOPS AND
EXPANDS OVER SW MO OVER THE NEXT FEW HOURS.  

RECENT RAP ANALYSIS SHOWS ERODING CINH ACROSS SW MO AND SE
KS...WITH RAPID DEVELOPMENT NOTED AT THE APEX OF CONVERGENT
BOUNDARIES ALONG THE OK/KS BORDER (FROM OUTFLOW FURTHER NORTH AND
STATIONARY FRONT).  WV LOOP/RAP ANALYSIS ALSO DENOTES ELEVATED
MIXED LAYER/BULGE NOTED ACROSS N OK ATTM MAXIMIZING CONVERGENCE ON
THE NORTHERN SIDE NEAR THE BOUNDARIES.  MOISTURE INGREDIENTS WITH
Q-AXIS EXTENDING FROM ADM TO OKM TO GMJ TO SGF WITH MID-70S TDS
AND THIS EML...SUPPORT MLCAPES NEARING 4000 J/KG LIKELY TO
INCREASE WITH CONTINUED MOISTURE FLUX/CONVERGENCE.  AS SUCH WITH
SWLY LOW LEVEL FLOW ORTHOGONAL TO THE EFFECTIVE BOUNDARY NOTED IN
VIS SHOULD SUPPORT HIGHLY EFFICIENT RAINFALL PROCESSES EVEN WITH
SOME LOSS TO HAIL STILL WITH RAIN RATES AT OR ABOVE 2"/HR ARE
LIKELY.  OF GREATER CONCERN IS THE ORIENTATION OF THE MEAN CLOUD
BEARING FLOW WHICH IS NEARLY PARALLEL TO THE BOUNDARY FROM SE KS
ACROSS S MO ALLOWING FOR TRAINING OF CONVECTION FURTHER COMPOUNDED
BY BACKBUILDING/UPSTREAM REDEVELOPMENT.  THIS IS BEST REPRESENTED
IN RECENT FEW OPERATIONAL HRRR RUNS SUGGESTING 2-4" RAINFALL
TOTALS THROUGH 00Z.  AS SUCH IT IS POSSIBLE THAT FLASH FLOODING
MAY OCCUR ACROSS SW MO AND POTENTIALLY INTO NORTHERN ROW OF
COUNTIES IN N CENTRAL  AR.  THIS WOULD BE OF PARTICULAR CONCERN
WHERE FFG WAS REDUCED FROM EARLY MORNING CONVECTION.

SATELLITE AND RADAR MOSAIC ALSO INDICATE CONVECTION IS FILLING IN
ALONG THE INVERTED SURFACE TROF ALONG THE KS/MO BORDER JUST S OF
THE KC METRO. DEEPER MST CONVERGENCE IS MAXIMIZED AT THE APEX OF
THE TROF INTERSECTING WITH THE OUTFLOW BOUNDARY BUT AS THESE CELLS
MOVE EAST...THERE IS A GOOD LIKELIHOOD OF TRACKING VERY CLOSE TO
THE AREAS AFFECTED BY THE ONGOING ELEVATED WAA CONVECTION
OCCURRING IN CENTRAL MO.  LEADING TO A SECONDARY MAXIMA/SWATH OF
HEAVY RAINFALL CAPABLE OF LOCALIZED FF THROUGH THE AFTERNOON
HOURS.

GALLINA

ATTN...WFO...EAX...LSX...LZK...MEG...PAH...SGF...TSA...

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

LAT...LON   38839370 38469174 37568976 36458970 36009030
            35929114 36359308 37339476 37899491 38749445