AWUS01 KWNH 042302
FFGMPD
MOZ000-ARZ000-TXZ000-OKZ000-050448-

Mesoscale Precipitation Discussion 0028
NWS Weather Prediction Center College Park MD
549 PM EST Wed Mar 04 2026

Areas affected...portions of TX & southeast OK

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

Valid 042248Z - 050448Z

Summary...Showers and thunderstorms are expected to increase in
coverage and organization over the next several hours.  Hourly
rain amounts to 2.5" with local maxima to 4" are possible, which
could lead to flash flooding, particularly in urban areas.

Discussion...GOES-19 water vapor imagery shows a positively tilted
shortwave extending from KS southwest into the TX Panhandle. 
Downstream across portions of central and northeast TX, showers
and thunderstorms with increasing vigor are forming under the
difluent flow aloft within a region of dilfuent 1000-500 hPa
thickness in the vicinity of a synoptic scale front.  A separate
and weaker thermal gradient extends ahead of the front from the TX
Hill Country northeast across the ArkLaTex and southern AR which
separates temperatures in the 80s (where skies are clearer) from
temperatures in the 70s and 60s.  Mid-level capping is eroding as
temperatures at 700 hPa are falling below 6C.  ML CAPE in the
region is 1500-2500 J/kg.  Precipitable water values are
1.25-1.45", and slowly rising.  Effective bulk shear is 25-35 kts
and increasing.

The expectation is for convection to continue to increase in
coverage and intensity over the next several hours as mid-level
capping continues to erode and both 850 hPa inflow and effective
bulk shear magnify.  A combination of cell mergers, cell training,
and mesocyclone formation would yield heavy rainfall within this
environment, with hourly amounts to 2.5" possible.  The mesoscale
guidance shows a splotchy signal for local totals of 2-4", but is
not showing much overlap spatially.  Used recent radar
reflectivity trends, 12z REFS, and 12z HREF guidance as a guide to
the MPD bounds.  The amounts possible would exceed three hourly
flash flood guidance values on an isolated basis; issues could be
greater in more sensitive urban areas. 

Roth

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

ATTN...WFO...EWX...FWD...LZK...OUN...SGF...SHV...SJT...TSA...

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

LAT...LON   36579268 35379291 33339539 32559602 30369765 
            30279928 31819961 33209826 34899655 36499482