MESOSCALE PRECIPITATION DISCUSSION 0882
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
520 PM EDT MON OCT 09 2017

AREAS AFFECTED...SOUTHEAST KS, NORTHEAST OK, & SOUTHWEST MO

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

VALID 092120Z - 100320Z

SUMMARY...THUNDERSTORMS ARE INCREASING IN COVERAGE ACROSS
SOUTHEAST KS.  HOURLY RAIN TOTALS UP TO 2" WITH LOCAL AMOUNTS TO
4" ARE POSSIBLE AS STORMS SPREAD INTO SOUTHWEST MO AND NORTHEAST
OK.

DISCUSSION...RECENT WATER VAPOR IMAGERY SHOWS WEAK SHORTWAVES
UPSTREAM ACROSS THE SOUTHERN HIGH PLAINS AND SOUTHERN PLAINS
HELPING TO INCREASE DIVERGENCE ALOFT NORTHEAST OF A FRONTAL WAVE
ACROSS NORTHERNMOST OK.  THIS HAS LED TO INCREASING CONVECTIVE
COVERAGE WITHIN A MU CAPE GRADIENT.  PRECIPITABLE WATER VALUES
UPSTREAM HAVE INCREASED A BIT LATELY, UP TO ~1.4" NEAR TULSA PER
GPS DATA.  INFLOW AT 850 HPA IS 25 KTS OUT OF THE SOUTH PER THE
TULSA VAD WIND PROFILE.  BULK SHEAR IN THE REGION IS 40-50 KTS PER
SPC MESOANALYSES.

WHILE CIN HAS BEEN ERODING RECENTLY, THE EROSION IS ONLY EXPECTED
TO CONTINUE FOR ANOTHER COUPLE HOURS BEFORE REDEVELOPING.  HEAVY
RAIN CORES SHOULD ATTEMPT TO MOVE EAST SOUTHEAST TO SOUTHEAST AT
30 KTS WITH TIME, AT A RIGHT ANGLE TO THE MEAN 850-400 HPA WIND,
WHICH LEADS TO THE POSSIBILITY OF CELL MERGERS ENHANCING RAIN
TOTALS.  MESOCYCLONES ARE ALSO POSSIBLE WITHIN THIS ENVIRONMENT,
WHICH CAN BE EFFICIENT FROM A HEAVY RAINFALL PERSPECTIVE.  HOURLY
RAIN TOTALS UP TO 2" ARE POSSIBLE, AND THE MOST RECENT MESOSCALE
GUIDANCE HAS A GOOD SIGNAL FOR LOCAL AMOUNTS UP TO 4".  WHILE
CELLS SHOULD ATTEMPT TO FORWARD PROPAGATE WITH TIME, RAP MASS
FIELDS HINT THAT THERE IS CONCERN FOR REDEVELOPMENT ALONG THE
SOUTHWEST FLANK OF THE EXPECTED COLD POOL IN NORTHEAST OK AFTER
SUNSET, SO USED A SIX HOUR WINDOW.

ROTH

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

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

LAT...LON   38579619 38059473 37469398 36799422 36569451
            36419486 36439556 36709609 37209662 38089691