MESOSCALE PRECIPITATION DISCUSSION 0237
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
434 PM EDT FRI MAY 19 2017

AREAS AFFECTED...SOUTHEAST KS & SOUTHWEST MO

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

VALID 192033Z - 200233Z

SUMMARY...SURFACE BASED CONVECTION IS BEGINNING TO FORM NEAR A
WAVE CLOSE TO THE CENTRAL OK/KS BORDER AT THIS TIME.  WITH
CONVECTIVE EXPANSION EXPECTED, HOURLY RAIN RATES UP TO 2" WITH
LOCAL AMOUNTS TO 5" COULD LEAD TO FLASH FLOODING.

DISCUSSION...A MESOSCALE WAVE NEAR THE CENTRAL KS/OK BORDER LIES
AHEAD OF A SHORTWAVE MOVING ACROSS SOUTHWEST KS.  PRECIPITABLE
WATER VALUES OF 1.25-1.5" LIE ACROSS THE REGION.  INFLOW AT 850
HPA IS CURRENTLY FOCUSED JUST AHEAD OF THE WAVE AT 25 KTS.  THE
WIND FLOW IS NEARLY UNIDIRECTIONAL WITH HEIGHT.  BULK SHEAR IN THE
0-6 KM LAYER IS 40-70 KTS, SUFFICIENT FOR ORGANIZED CONVECTION AND
THE FORMATION OF MESOCYCLONES.  MLCAPES OF 2000 J/KG LIE AHEAD OF
THE WAVE, AND RECENT SPC MESOANALYSES SHOW A SLOW EROSION TO CIN
IN THE AREA.

WITH TIME, THE FLOW INTO THE FRONTAL BOUNDARY IS EXPECTED TO
BECOMING INCREASINGLY CYCLONIC WHICH SHOULD ALLOW CONVECTION TO
EXPAND EASTWARD INTO WESTERN MO WITH TIME, WHICH IS CURRENTLY
SEEING THEIR FIRST ROUND OF ACTIVITY.  PRECIPITABLE WATER VALUES
SHOULD INCREASE SLIGHTLY FURTHER.  THIS IS IMPLIED WITHIN THE 12Z
GFS-BASED GALVEZ-DAVISON INDEX, WHICH SHOWS VALUES BROACHING 35 AT
00Z IN SOUTHEAST KS.  CIN SHOULD REDEVELOP TOWARDS THE END OF THE
MPD PERIOD ACROSS KS/MO, WHICH COULD ALLOW CONVECTION TO SHIFT
NORTH TOWARDS THE 850 HPA SLICE OF THE WARM FRONT.  THE MESOSCALE
GUIDANCE APPEARS TOO FAR NORTH WITH QPF FOR THE MOST PART --
BELIEVE THE LAST FEW RAP RUNS HAVE THE BEST CLUE HERE.  THEY AGREE
ON A SIGNAL FOR LOCAL AMOUNTS OF 5" IN THIS AREA.  HOURLY RAIN
RATES UP TO 2" ARE POSSIBLE WHERE CELLS TRAIN/MERGE.

ROTH

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

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

LAT...LON   39299518 39029245 38199163 36869171 36569283
            36589443 36909541 37059752 37019798 37199894
            38359771