890
AWUS01 KWNH 221735
FFGMPD
TXZ000-OKZ000-222200-

Mesoscale Precipitation Discussion 1042...Corrected
NWS Weather Prediction Center College Park MD
134 PM EDT Sun Sep 22 2024

Corrected for Resend of Text

Areas affected...Southwest to Central East OK...Southeast TX
Panhandle...

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

Valid 221700Z - 222200Z

SUMMARY...Potential for elevated training cells with rates slowly
increasing as cells approach surface front and deep moisture flux
inflow.  Isolated rates up to 2"/hr and totals of 2-3" may result
in localized flash flooding particularly near urban or hard/baked
ground conditions.

DISCUSSION...16z surface analysis depicts a stationary front from
TQH at the the southward sagging cold front across the MOKSAROK
across to SRE to OUN to FSI and a low near FDR before becoming a
bit less defined across NW Texas into deeper low level status.
This stratus is banked in west of the surface low, but also within
the best isentropic ascent from return Gulf moisture along the low
level jet.   Upper-level jet is sliding east and as such, the
mid-levels quickly veering across 850-700mb resulting in
convergent flow aloft of the Eastern Cap Rock into SW OK.  Modest
500-1000 J/kg of MUCAPE and the FGEN forcing has been breaking out
convection for the last few hours with increasing coverage across
TX. Total moisture values through this eastward angling moisture
plume are fairly solid at at 1.5-2 standard anomaly units above
average between 1.5-1.75", but slowly climbing with the addition
of the return Gulf moisture and increasing confluence into the
mid-levels.  As such, rainfall rates are slowly increasing from
1-1.5"/hr into an increasingly favorable steering flow allowing
for training elements over the next few hours.

Recent drought conditions resulting in very high FFG values are
likely still too high for these rates (with exception of central
Cap Rock where values are more approachable); however, as the
cells move eastward, the proximity to the surface front reduces
and bases are lowering and trying to root more toward the surface.
 This is allowing for increased moisture flux into the updrafts
with Tds in the upper 60s.  As a result, rainfall rates are
starting to increase to around 2"/hr with some occasional as well
a approaching increased urbanization.  While 1hr FFG values are
still above 2.5"; the prolonged drought may have further hardened
the upper ground surface making infiltration even more difficult
and so may be over-estimating FFG.  While, not likely to be large
scale or significant in magnitude, isolated flash flooding is
considered  possible over the early afternoon hours across the
repeating/training corridor particularly near urban centers.

Gallina

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

ATTN...WFO...AMA...LUB...OUN...TSA...

ATTN...RFC...ABRFC...WGRFC...NWC...

LAT...LON   36109607 36069525 35799487 35339499 34969571
            34729672 34459805 34099985 33890132 34520180
            35150101 35629991 35919906 36089804 36069700