969
AWUS01 KWNH 050048
FFGMPD
MOZ000-ARZ000-OKZ000-KSZ000-050545-

Mesoscale Precipitation Discussion 0558
NWS Weather Prediction Center College Park MD
847 PM EDT Thu Jul 04 2024

Areas affected...Northeast & Eastern OK...Southwest MO...Northwest
AR...

Concerning...Heavy rainfall...Flash flooding possible

Valid 050045Z - 050545Z

SUMMARY...Weakly organized convection within very rich moisture
field may produce locally intense rainfall that may produce a few
incidents of flash flooding.

DISCUSSION...Current regional RADAR mosaic depicts scattered
thunderstorms across eastern OK that have developed in very weak
low level flow environment.  While environment has been very
unstable with 3500-4000 J/kg of CAPE, inflow at cloud base has
been limited to less than 10kts and 7H wind field has shown
divergence across the area to limit organization in the near term;
with new development sprouting on older outflow.  Still, moisture
rich environment with over 2-2.25" total PWats result in quick 2"
in about an hour, before collapsing.   This alone is not going to
exceed the very high FFG values, but with soil saturation below
15% across much of eastern OK, this hard ground may not allow much
infiltration given these intense sub-hourly rates and may result
in very high run off.  Given the broader up/downdrafts, these may
cross multiple smaller watersheds (or urban centers) resulting in
lower-end localized flash flooding conditions.

As night falls, surface analysis and RAP trends show the cold
front is starting to press southward across SE KS given stronger
height-falls as the mid-level trough starts digging and the jet
streak starts to expand right entrance region divergence
downstream across SW MO/NW AR.  While slightly drier, there
remains a shallow moisture pool post front, so with strengthening
15-25kts of west to northwest flow counter to the 5-10kts of
southwest/south flow, moisture convergence will increased in
proximity the boundary and overall convective coverage will
increase from scattered to numerous.  Divergence/outflow and DPVA
may aid overall organization of convection with some repeating
elements crossing over to SW MO/NW AR after nightfall.  Similar
2-2.5"/hr rates will result in spots of 2-3"; this may be most
concerning for the lowered FFG across S MO where there has been
recent rainfall, but again; sub-hourly intensity across harder
ground conditions further south in AR may also result in possible
spotty incidents of flash flooding.

Gallina

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

ATTN...WFO...LZK...OUN...SGF...TSA...

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

LAT...LON   37979268 37659167 36899128 35909162 35379242
            34959405 34789548 35219656 36199669 36719618
            36989505 37499407