446
AWUS01 KWNH 150731
FFGMPD
ARZ000-TXZ000-OKZ000-151300-

Mesoscale Precipitation Discussion 0693
NWS Weather Prediction Center College Park MD
330 AM EDT Tue Jul 15 2025

Areas affected...Southeastern Oklahoma...Western Arkansas...

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

Valid 150730Z - 151300Z

SUMMARY...Compact shortwave with upstream confluent flow across
recently saturated ground poses localized 2-3.5" totals resulting
in possible localized flash flooding.

DISCUSSION...GOES-E 3.9um animation shows the compact mid-level
shortwave continuing to slowly drift northeast currently along the
central OK/AR border; though it appears to be
stretching/elongating toward the northeast within the larger
stagnant positive tilt trough axis that dominates the eastern
third of the U.S.  Feathered transverse banding in the cirrus
canopy along and to the northeast of the wave suggest some right
entrance left support/outflow which is likely strengthening the
wave and slowly increasing the low-level wind response.  VWP
across the region and RAP analysis support this with broad low
level veering indicating WAA upstream across NE TX to central AR.
While surface observations suggest the flow is generally confluent
across the southwest quadrant of the wave supporting some
isentropic ascent/deep layer moisture convergence across SE OK
resulting in a new increase in convective flare up across the most
saturated ground conditions in Pushmataha to Le Flore counties.
Though strongest convective responses are within the best
confluence and speed convergence along the northeast and eastern
quadrants of the wave across west central AR and crossing I-40 NE
of Ft. Smith.

Moisture has been the least of concerns and remains well above
average with total PWat values remaining in the 2.25" range near
the core, resulting in deep warm cloud processes and efficient
rainfall production even with slightly weaker updraft strength.
Still, confluent air is still fairly buoyant with 1500-2000 J/kg
of narrow skinny CAPE profiles to work with and likely support
2"/hr rates (though updraft widths maybe narrower than desired for
larger rainfall footprints for random repeating/intersections).
Still, deep layer steering is along the deep layer shear/trough
axis and may support some of those repeating, short-term training
incidents.  Slower cell motions very close and downstream of the
shortwave center will likely result in the greatest duration and
overall totals up to 3.5".  Given the overall pattern has been
stubborn, the heavy rainfall also aligns with the lowered FFG
(esp. in SE OK) and rates of 2"/hr and totals of 2-3" are near the
local FFG and suggests an incident or two of localized flash
flooding remains possible through the early morning diurnal peak
toward day-break.

Gallina

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

ATTN...WFO...LZK...OUN...SHV...TSA...

ATTN...RFC...ORN...TUA...NWC...

LAT...LON   36469330 36079261 35609251 35059274 34359333
            33949414 33899502 33969595 34269633 34699606
            34879552 35379467 36349419