566
AWUS01 KWNH 262024
FFGMPD
ARZ000-TXZ000-OKZ000-270200-

Mesoscale Precipitation Discussion 0185
NWS Weather Prediction Center College Park MD
423 PM EDT Sat Apr 26 2025

Areas affected...Eastern OK...Western AR...Adj Far Northeast TX...

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

Valid 262025Z - 270200Z

SUMMARY...Slow moving thunderstorms in warm sector ahead of dying
MCV to support 1.75-2"/hr rates and scattered spots of 2-4"
totals.  While FFG values are high, an isolated incident of flash
flooding or two may be possible.

DISCUSSION...Last night`s MCS continues to decay with some
remaining ongoing fractured convective activity along the leading
edge where DPVA intersects some elevated unstable energy across
east-central OK eventually into NW AR.  The main MCV is nearly
fully occluded and is shearing out as it moves NNE along the KS/OK
boarder.  However, mid-level jet streak over the Red River, likely
in larger scale synoptic diffluent region of the 3H jet is
starting to strengthen the effective triple point mid-level
circulation and develop a newer MCV across south-central OK.  This
wave as strengthened low level flow across northeast TX advecting
higher low 70s sfc Tds and some warmer air within the clear sector
to support 2500 J/kg of MLCAPE across SE OK toward Texarkana.

The sharp frontal zone has resulted in weak directional low level
confluence along its axis and new thunderstorms are developing
south of the main old stationary front further north across SE OK.
 These WAA induced cells have solid bulk shear for updraft
rotation to support increased localized moisture flux convergence
along the pooling q-axis due to isallobaric influence.  As such,
moisture loading along with slowed forward propagation is allowing
for efficient low level rain-fall production with 1.75-2"/hr rates
becoming increasingly probable over the next few hours.  ENE cell
motions may allow for some cross tracks for the most intense
downdrafts and spots of 2-4" are considered possible through the
evening hours, particularly along and south of the surface front
into central western AR.

NASA SPoRT LIS products denote the area of concern is mainly
aligned with RSM 0-40cm at average or slightly below average in
the 45-50% range.  This also aligns with the higher FFG values
across the region, so even with the intense rainfall, it still may
be difficult to exceed those values, especially further south and
east near the Red River Valley where 3"/hr and 4"/3hr is
apparently required to induce FF.  Still, the overall organization
and prolific history with the overall system and favorable
moisture/instability environment still hints at one or two
isolated low-end flash flooding incidents may still remain
possible through this evening.

Gallina

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

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

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

LAT...LON   36159508 36079443 35879395 35599355 35049318
            34039305 33559373 33559511 33689672 34399705
            34899629 35539564 35929543