MESOSCALE PRECIPITATION DISCUSSION 0365
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
819 PM EDT TUE JUN 26 2018

AREAS AFFECTED...NEAR THE MO/KS/AR/OK BORDER JUNCTION

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

VALID 270017Z - 270417Z

SUMMARY...THUNDERSTORMS ARE INCREASING IN COVERAGE AND INTENSITY
ACROSS SOUTHEAST KS AND SOUTHWEST MO.  HOURLY RAIN TOTALS TO 2"
WITH LOCAL AMOUNTS TO 4" ARE POSSIBLE.

DISCUSSION...THUNDERSTORMS ARE BLOSSOMING NEAR AND DOWNWIND OF A
SIGNIFICANT INSTABILITY POOL IN KS, DRIVEN BY A NARROW CORRIDOR OF
MID 70F DEWPOINTS ADVECTING INTO SOUTH-CENTRAL KS.  ML CAPE VALUES
ARE 2000-6000 J/KG, WHICH HAS LED TO A RAPID CONVECTIVE EXPANSION
JUST SOUTH OF A SHARP SHORTWAVE TROUGH NOTED ON WATER VAPOR
IMAGERY MOVING BY KANSAS CITY.  STORMS ARE ORGANIZED AS EFFECTIVE
BULK SHEAR IS 30-50 KTS.  INFLOW AT 850 IS CONVERGENT, THOUGH
SOMEWHAT ANTICYCLONIC, FROM THE SOUTHWEST AT 25-30 KTS PER VAD
WIND PROFILES.  PRECIPITABLE WATER VALUES ARE 1.5-1.9" PER GPS
VALUES.

SOME OF THE MESOSCALE GUIDANCE APPEARS TO HAVE A GRASP OF THIS
ACTIVITY, AND INDICATE LOCAL AMOUNTS OF 4" ARE POSSIBLE, WITH
UPWARD TRENDS NOTED LATELY IN THE HRRR/EXPERIMENTAL HRRR GUIDANCE.
 HOWEVER, CURRENT CELL COVERAGE APPEARS TO EXCEED GUIDANCE
EXPECTATIONS.  CELL COLLISIONS, POSSIBLE SHORT BOUTS OF TRAINING,
AND MESOCYCLONES APPEAR TO BE THE MAIN HEAVY RAIN THREAT IN THIS
AREA.  THE EXPECTATION IS THAT A COLD POOL WILL BUILD OVER THE
NEXT FEW HOURS AND THAT STORMS WOULD EVENTUALLY FORWARD PROPAGATE
SOUTHEAST PARALLEL TO THE MU CAPE GRADIENT/ OUTFLOW BOUNDARY INTO
NORTHEAST OK AND NORTHWEST AR AT 30-35 KTS WITH TIME.  A LIMITING
FACTOR, OTHER THAN EVENTUAL FORWARD PROPAGATION, WOULD BE
RELATIVELY HIGH FLASH FLOOD GUIDANCE VALUES ACROSS MUCH OF THE
AREA.  HOURLY RAIN TOTALS UP TO 2" SHOULD BE POSSIBLE IN THIS
ENVIRONMENT UNTIL FORWARD PROPAGATION MATERIALIZES TO THE
SOUTHEAST.

ROTH

ATTN...WFO...EAX...ICT...LZK...SGF...TOP...TSA...

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

LAT...LON   38319544 38219388 37229290 36409266 36189403
            36309557 36749637 37679745 38309768 38309685