445
AWUS01 KWNH 190037
FFGMPD
OKZ000-KSZ000-190606-

Mesoscale Precipitation Discussion 0462
NWS Weather Prediction Center College Park MD
837 PM EDT Tue Jun 18 2024

Areas affected...Southwest Kansas...Oklahoma Panhandle

Concerning...Heavy rainfall...Flash flooding likely

Valid 190036Z - 190606Z

Summary...A semi-discrete line of supercell thunderstorms
continues to evolve along the triple-point in Southwest Kansas.
Training combined with slow storm motions of 5-15 kts may lead to
locally very heavy rainfall upwards of 5-6" through 6z.

Discussion...Radar across Southwest Kansas shows a broken line of
semi-discrete supercells which emerged from an initially linear
slab of convection along a slow moving cold front. Recently, the
orientation of these supercells has started to align along a more
west-east axis, and are exhibiting a training and backbuilding
signal along the KS-OK border near the Liberal, KS area as new
deep convection forms along a now retreating dryline and stalled
cold front.

Recent mesoanalysis estimates depict a very unstable environment
upstream of the convection, including 3000-4000 J/kg MUCAPE and
1.4-1.6" PWATS. Effective shear values are a bit on the weak side
(20-25 kts), although storm-relative anvil layer flow to the
northeast may alleviate the lack of overall shear as storms move
eastward along the Bunkers RM vector. Combined with strong
low-level theta-e advection and increasing 1000-850 mb moisture
convergence, the concern is for backbuilding and training on the
southwest flank of the ongoing activity to continue going into
tonight.

The HREF continues to be quite aggressive going into tonight with
this current activity, and shows very high (60-70%) probabilities
of 6 HR QPF exceeding 3" through 6Z over Southwest Kansas, with an
appreciable (30-35%) chance of 100 year ARI exceedence noted
there. While antecedent conditions are generally dry across the
region (according to NASA SPORT soil moisture percentiles), this
focused corridor of very heavy rainfall will likely drive a risk
of flash flooding through 6Z, some of which may be locally
considerable.

Asherman

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...AMA...DDC...OUN...

ATTN...RFC...ABRFC...NWC...

LAT...LON   37620029 37529966 37219959 36999976 36800022
            36680073 36620119 36690167 36970183 37330175
            37510115