176
FXUS64 KLUB 281735
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
1235 PM CDT Mon Sep 28 2026

...New SHORT TERM, LONG TERM...

.KEY MESSAGES...
Updated at 1228 PM CDT Mon Sep 28 2026

 - Heavy showers and thunderstorms are expected mainly Tuesday
   afternoon through early Wednesday morning, with flooding
   possible especially near the TX/NM state line.

 - A Flood Watch is in effect for the SW TX Panhandle and
   northwestern portions of the South Plains.

 - A few severe storms are possible Tuesday afternoon over much of
   the Caprock.

 - Generally drier and cooler weather is expected Thursday and
   beyond.

&&

.SHORT TERM...
(This evening through Tuesday)
Issued at 1228 PM CDT Mon Sep 28 2026

Modest upper level ridging remains in place over the region at
midday Monday, resulting in one more afternoon of warm and dry
weather over West TX before a potent storm system takes shape over
the next 24 hours. An upper low currently digging southward over the
Sierra NV range will center just south of Las Vegas NV by early
Tuesday morning as TC Polo makes landfall along the Baja Peninsula.
This evolution will result in a rapid moistening of the column as
southwesterly flow aloft intensifies over the region, with the
middle and upper atmosphere progged to saturate quickly by Tuesday
morning. Large-scale forcing for ascent will initially be relatively
weak, but scattered showers are still expected to develop over the
Caprock during the first half of the day Tuesday as PWATs surge
above 1.5" and a few weak leading shortwave disturbances transit
over SE NM.

This initial activity Tuesday morning is not expected to be
particularly heavy and should be most concentrated near the state
line. Given the thick overcast in place overhead, temperatures
will also be notably cooler Tuesday on the Caprock, especially
over the SW Panhandle where highs will not make it out of the 70s.
Quite a gradient in high temperatures will exist across the rest
of the region, with mid 80s to low 90s expected off the Caprock.
Overall, we currently expect a relative lull in precipitation
midday Tuesday as the initial batch of weak forcing wanes.
However, robust heating on the warm side of the temperature
gradient could spark a few scattered thunderstorms during the
afternoon mainly over the Rolling Plains and SE TX Panhandle. The
heavier and more widespread rainfall (and the biggest threat for
flooding) is not expected to materialize until later Tuesday
evening and beyond, discussed below.

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 1228 PM CDT Mon Sep 28 2026

By Tuesday evening, the remnants of TC Polo are progged to have
largely phased with the broader upper low, resulting in a plume of
significant and anomalous moisture flowing over NM and adjacent West
TX with PWATs approaching 2" (nearly 4 standard deviations above
normal) in spots. Heavy showers and thunderstorms are expected to
increase in coverage especially after 00z Tuesday as an upper level
vort max associated with the remnants of Polo results in a notable
increase in large scale forcing for ascent. The surface and low
level response will also be fairly significant with most models
depicting a sub-1000mb surface low developing over SE NM which will
result in strong sustained winds over the Caprock Tuesday night. The
current expectation is that one or more broken lines of
thunderstorms will move over our area Tuesday evening through the
overnight hours into early Wednesday, with the highest coverage of
storms occurring to the west of I-27.

A few severe storms are possible Tuesday evening, with forecast
soundings depicting strong flow up to the tropopause and surface-
based CAPE exceeding 1000 J/kg despite an elongated profile. This
combined with 30-40kt of SSW flow in the 850-700mb layer will
support the potential for isolated severe wind gusts, in addition
to a nonzero tornado threat over portions of the South Plains
given the presence of backed surface flow. However, the primary
hazard associated with this event is the potential for numerous
instances of flash flooding given training storms and highly
efficient rainfall. Hi-res ensemble suites still favor areas
along and west of a line from Tulia to Littlefield to Morton for
the heaviest rainfall totals and highest risk of flash flooding,
and a Flood Watch remains in effect for the SW Panhandle and NW
South Plains. Areas in the Flood Watch generally have a 50-70%
chance of rainfall totals exceeding 2" through Wednesday morning.
Swaths of 3-4" are also not out of the question, though totals of
this magnitude will be more common to our west and north over NM
and towards I-40. Rainfall totals are expected to decrease fairly
quickly with eastward extent, with some locations east of I-27
potentially only seeing a half inch or less.

The bulk of the heavy precipitation is expected to end by Wednesday
morning as a dry slot punches eastward on the southern end of the
upper low. Although some lingering scattered showers are a good bet
through much of Wednesday, additional rainfall totals will only be
light. Another window for severe storms will then open Wednesday
afternoon and evening, this time across the Rolling Plains along and
east of a dryline. This threat should concentrate mainly to our
east, but a few instances of large hail and damaging winds could
materialize on Wednesday over our eastern zones. For the rest of the
week, the forecast generally trends drier and cooler. There will be
some potential for a few showers late week mainly off the Caprock,
but our current expectation is for most locations to remain dry
Thursday and beyond. The more noticable change will be much cooler
temperatures with highs currently forecast in the 60s and 70s
Thursday and Friday.

&&

.AVIATION...
(18Z TAFS)
Issued at 1139 AM CDT Mon Sep 28 2026

VFR and generally light southerly winds will continue through the
TAF period. CIGs will fall tonight for KLBB and KPVW, however much
of the incoming precipitation for the TAF sites will occur beyond
the current period.

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch from Tuesday morning through Wednesday afternoon for
TXZ021>023-027-028-033.

&&

$$

SHORT TERM...30
LONG TERM....30
AVIATION...19