324
AWUS01 KWNH 212359
FFGMPD
TXZ000-OKZ000-NMZ000-220555-

Mesoscale Precipitation Discussion 1039
NWS Weather Prediction Center College Park MD
758 PM EDT Sat Sep 21 2024

Areas affected...TX Panhandle into adjacent eastern NM/western OK

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

Valid 212357Z - 220555Z

SUMMARY... Repeating and training of cells are expected to pose a
threat for flash flooding from the TX Panhandle into adjacent
eastern NM/western OK through 06Z. Rainfall rates of 1-2 in/hr and
totals of 2-4 inches are expected.

DISCUSSION...2330Z radar imagery showed a small cluster of
thunderstorms advancing through the western TX Panhandle, with
more widely scattered coverage extending westward into eastern NM.
These cells were forming out ahead of a potent mid-level trough
over the Four Corners region, which was advancing toward the ENE,
with favorable shear for organized cells in place over the High
Plains. While most cells were moving toward the NE at 25-35 kt,
some deviant rightward motion of organized cells has been observed
and instances of training have supported MRMS-derived rainfall
rates of about 1-2 in/hr. Surface observations showed an effective
cold front (outflow boundary enhancement) extended southwestward
through northwestern OK into the TX Panhandle, and then
west-northwestward into NM. A pool of 1000 to 2000+ J/kg MLCAPE
was estimated via the 23Z SPC mesoanalysis from just south of AMA
into eastern NM along with anomalous precipitable water values
that ranged from 1.3 to 1.7 inches.

A strengthening low level jet is forecast with 25 to 35+ kt
through 06Z at 850 mb, which will act to overrun the southward
sinking effective cold front. Moisture pooling and elevated
instability of up to 1500 J/kg is forecast by the RAP to focus
over the TX Panhandle north of the boundary, with weaker values of
up to 500 into western OK. After the initial round of
thunderstorms advances east from the western TX Panhandle,
subsequent rounds are anticipated as the low level jet ramps up
overnight, leading to instances of repeating and training due to
the similar boundary orientation and anticipated storm motions.
Rainfall rates should generally fall in the 1-2 in/hr range and
total rainfall of 2-4 inches through 06Z may lead to some areas of
flash flooding, though dry antecedent conditions may limit flash
flooding to urban areas or otherwise flashy locations across the
region.

Otto

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

ATTN...WFO...ABQ...AMA...LUB...OUN...

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

LAT...LON   36240090 36210007 35829981 35149991 34370074
            33860247 33950309 34330322 34830311 35300282
            35870192