520
AWUS01 KWNH 031637
FFGMPD
MOZ000-ARZ000-TXZ000-OKZ000-KSZ000-032235-

Mesoscale Precipitation Discussion 0386
NWS Weather Prediction Center College Park MD
1236 PM EDT Mon Jun 03 2024

Areas affected...much of OK...western AR...far southwest MO...far
southeast KS...portions of far northern TX

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

Valid 031635Z - 032235Z

Summary...Rainfall rates of 1-3"/hr to continue to be supported
with additional localized totals of 3-5". Isolated to scattered
instances of flash flooding are possible (with particular concern
for more sensitive soils surrounding the Red River of the South).

Discussion...A mesoscale convective vortex (MCV) and remnant
surface outflow continue to support new convective development
across portions of the Southern Plains late this morning. The
mesoscale environment at 15z was characterized by MU CAPE of
1000-3000 J/kg, precipitiable water (PWAT) values of 1.4-1.8"
(between the 90th percentile and max moving average, per SPC
sounding climatology), and effective bulk shear of 20-40 kts.
Given the established cold pool and progressing outflow, there is
an expectation for a mix of surface-based and elevated convective
development as a southwesterly 20-30 kt low-level jet (LLJ)
continues to usher in moderate moisture transport. The strongest
convection is expected to be surface-basd along the advancing
outflow, where instability and shear are maximized, and resulting
totals will be dependent on the progression of this outflow and
the accompanying updrafts.

Hi-res CAMs are providing a decent depiction of the ongoing
convection, considering the complexity of modeling an MCV and the
attendant outflow. The HRRR in particular has done a good job
since 12z keeping up with the observational trends, which has
shifted the expection for QPF maxima southward (compared to
earlier runs and the HREF PMM) with the advancing outflow
(approaching the more sensitive soils surrounding the Red River of
South). Despite this modest spatial shift, the guidance remain in
relatively good agreement regarding coverage and intensity of
convection going forward, suggesting localized rainfall rates of
1-3"/hr (which have already been ongoing for much of the morning,
per MRMS esitmates) with isolated to scattered totals of 3-5" (per
40-km HREF 3" neighborhood exceedance probabilites of 30-50%).
Given the relative lack of confidence in prolonged 1-3"/hr
rainfall rates due to training or repeating (and with FFGs
generally ranging from 2-4"), isolated to scattered instances of
flash flooding are considered possible.

Churchill

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

ATTN...WFO...FWD...ICT...LZK...OUN...SGF...SHV...TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...WGRFC...NWC...

LAT...LON   37649434 37349370 35459288 34489313 33839352
            33469394 33219484 33159630 33289734 33639899
            34619976 35389836 35879748 36299689 36859619
            37489543