MESOSCALE PRECIPITATION DISCUSSION 0147
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
919 PM EDT MON MAY 14 2018

AREAS AFFECTED...PORTIONS OF SOUTHEAST KS

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

VALID 150118Z - 150608Z

SUMMARY...THUNDERSTORMS CONTINUE TO FESTER NEAR THE INTERSECTION
OF A FRONTAL ZONE, DRYLINE, AND OUTFLOW BOUNDARY.  HOURLY RAIN
TOTALS TO 2" WITH LOCAL AMOUNTS TO 4" ARE EXPECTED.

DISCUSSION...THUNDERSTORMS WITH HEAVY RAIN THRIVE NEAR NORTHERN
GREENWOOD AND NORTHERN BUTLER COUNTIES WITH RADAR ESTIMATES
(ALBEIT SLIGHTLY CONTAMINATED BY HAIL) OF 2" AN HOUR. 
PRECIPITABLE WATER VALUES OF OVER 1.5" LIE WITHIN THE CONVECTIVE
ENVIRONMENT OVER EASTERN KS PER GPS VALUES.  INFLOW AT 850 HPA IS
SOUTHWEST AT 20 KTS, WHICH IS IMPORTING MU CAPE VALUES OF
3000-4000 J/KG INTO THE STORMS.  EFFECTIVE BULK SHEAR OF 30-40 KTS
IS ORGANIZING THE CONVECTION.

BOTH THE 22Z HRRR AND 12Z SPC WRF APPEAR TO HAVE A GOOD HANDLE ON
THIS ACTIVITY.  AN MCV ACROSS WESTERN OK -- SEEN ON HRRR
REFLECTIVITY AND BEGINNING TO SHOW UP ON RADAR IMAGERY -- RIDES
NORTHEAST TOWARDS THE NEARLY STALLED THUNDERSTORMS INCITING NEW
DEVELOPMENT BETWEEN NORTHERN OK AND SLOW-MOVING CLUSTER, WHICH IS
AIDED BY A SLOWLY RETREATING DRY LINE AND SLOWLY ADVANCING OUTFLOW
BOUNDARY.  CELL COLLISIONS/BACKBUILDING ARE EXPECTED TO LEAD TO A
HEAVY RAIN THREAT.  ONE AREA THE HRRR APPEARS TO OUTSHINE THE WRF
NSSL IS IN BRINGING THE SUPERCELL IN WESTERN KS INTO PLAY, WITH IT
AND ITS ASSOCIATED WEAK SHORTWAVE ALOFT ACTING AS ANOTHER
RAIN-ENHANCING CELL MERGER POSSIBILITY IN THE 04-05Z TIME FRAME. 
SINCE SOME MOVEMENT IS ANTICIPATED TO THE THUNDERSTORM ACTIVITY,
FLASH FLOOD GUIDANCE VALUES AREN'T PARTICULARLY LOW, AND SOME
COMPLEX CELL INTERACTION IS EXPECTED, CONTINUE TO USE THE POSSIBLE
CATEGORY. 

ROTH

ATTN...WFO...DDC...ICT...OUN...TOP...TSA...

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

LAT...LON   38789708 38549569 38079521 37509510 37089570
            36569742 36669880 37479874 38159831