810
AWUS01 KWNH 031226
FFGMPD
ARZ000-TXZ000-OKZ000-031730-

Mesoscale Precipitation Discussion 0578
NWS Weather Prediction Center College Park MD
826 AM EDT Thu Jul 03 2025

Areas affected...Central and Eastern Oklahoma through Southern
Arkansas

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

Valid 031225Z - 031730Z

Summary...An axis of showers and thunderstorms will continue to
train across eastern Oklahoma this morning. Rain rates of 1-2"/hr
are expected within this convection, leading to 2-3" of rain with
locally higher amounts. Flash flooding is possible.

Discussion...The regional radar mosaic this morning shows an axis
of expanding convection oriented NW to SE across eastern Oklahoma.
This convection is blossoming along an elevated 700mb front north
of a surface boundary draped over eastern Texas, with persistent
isentropic ascent and moisture confluence occurring into the
boundary on 850-700mb winds of 15-25 kts measured via local VWPs.
Moisture is impressive across the area with PWs around 2.1 inches
(above the 90th percentile) and 700-500mb RH above 90%. With 700mb
winds gradually veering and converging into this front, moisture
confluence is maximized along this boundary, which in combination
with the accompanying lift is driving the ongoing thunderstorm
activity.

The CAMs are struggling to initialize both the breadth and
intensify of the morning thunderstorms, leading to a lower than
typical confidence for the evolution the next few hours. However,
the ARW and ARW2, as well as the recent RRFS, all at least hint at
the activity and are used to help forecast the flash flood risk.
The setup will remain favorable for continued convection as
moisture confluence into the boundary combined with the
convergence will focus development along this axis. Mean 0-6km
winds will remain light at just 5-10 kts, and with Corfidi vectors
aligned parallel to the boundary and anti-parallel to the mean
wind, an enhanced risk for backbuilding and training of cells will
continue at least until the 850-700mb inflow weakens in the next
few hours. Although the axis of heavy rainfall is expected to be
narrow and focused along this elevated boundary, near-record PWs
and a slow rise in MUCAPE will support rain rates above 1"/hr,
which through training will create stripes of 2-3" of rain with
locally higher amounts.

FFG across the region is generally elevated at 2.5-4"/3hrs due to
a lack of recent rainfall across most of the discussion area, but
0-10cm soil moisture from NASA SPoRT has not fully dried and is
still above the 90th percentile in many areas. This suggests that
infiltration capacity of the soil is somewhat limited. So, where
training can occur (to saturate the soils and then overwhelm
them), instances of flash flooding are possible, but will be most
likely across urban areas or where the most pronounced training
does occur.


Weiss

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

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

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

LAT...LON   36129736 36029613 35629516 35019440 34119356
            33669337 33099367 33019447 33239507 33269527
            33859660 34339764 34879814 35689808