Flomot, Texas Weather Forecast Discussion

477
FXUS64 KLUB 221730
AFDLUB
Area Forecast Discussion
National Weather Service Lubbock TX
1230 PM CDT Mon Sep 22 2025
...New KEY MESSAGES, SHORT TERM, LONG TERM, AVIATION...
.KEY MESSAGES...
Updated at 1230 PM CDT Mon Sep 22 2025
- Isolated showers and thunderstorms are forecast across portions
   of the Caprock tonight into early Tuesday morning.
- Storm chances return Tuesday afternoon for portions of the Caprock
   and Rolling Plains.
- Relatively cool on Wednesday before warmer weather returns for
   the end of the week.
&&
.SHORT TERM...
(This evening through Tuesday)
Issued at 1230 PM CDT Mon Sep 22 2025
In the mid/upper-levels, a semi-progressive, wavy pattern enveloped
North America, with an amplified, subtropical ridge centered over
the central Sierra Madre Occidental; a train of shortwave troughs
pivoting across the northern CONUS; and a closed low rotating
offshore SoCal. The anticyclonically-curved 250 mb jet streak arcing
over the apex of the subtropical ridge was objectively analyzed at
nearly 100 kt on the 12Z UA charts, with the CWA located beneath the
right-exit region to this jet streak. Mid-level flow was
substantially weaker, but still near 20 kt, as per neighboring RAOBs
and satellite estimates. The low-level jet remained veered due to a
much more expansive and stronger 850 mb ridge rotating over the Deep
South relative to the convectively-contaminated pattern farther west
and beneath the subtropical ridge. Over the next 24 hours, the CWA
will be positioned between the inflection point of the shortwave
trough digging into the central Rocky Mountains and the subtropical
ridge meandering over central Mexico. As is typical with strong,
cross-barrier flow, a mountain wave is present, and is visually
evident by the thin, narrow band(s) of high-altitude cirrostratus
advecting over W TX. The low-level jet will back by this afternoon
in response to the leeward pressure falls generated by these
mountain waves, which will persist through the short-term period.
At the surface, winds were veered across most of the Caprock, with
an east-west-oriented trough that has mixed northward into the far
southern TX PH. Another diffuse surface trough was analyzed along a
line from near AMA-PVW-HOB, with a weak cyclone located near
Northfield on recent WTM data. The wind shift was negligible with
both of these surface troughs, but differential vertical mixing was
evident on WTM data, with upper 40 degree dewpoints observed near
the NM state line while spiking to 60+ degrees along and east of the
I-27 corridor. Cyclogenesis will continue throughout the day, with
winds expected to back towards the south near dusk from the weak,
isallobaric response generated by the surface low in the far
southern TX PH and another low in southeastern CO. Very deep mixing
of the boundary-layer is expected this afternoon, with record high
temperatures forecast at LBB, or 98 degrees, which was previously
set in 1977. Records will fall short in CDS; however, temperatures
are expected to breach 100 degrees across most of the Rolling Plains
this afternoon. Despite the presence of the weak cyclone and the
attendant surface trough, convergence will be negligible and nowhere
near enough to overcome the mid-level subsidence layer, which will
be about 100 mb higher than the LCL (e.g., LCLs near 650 mb). Dry
and hot conditions are expected area-wide through 00Z this evening.
After sunset, isolated-to-widely-scattered showers and thunderstorms
are forecast to move across portions of the Caprock. A well-defined,
shortwave perturbation, with a baroclinic leaf-like appearance on
water-vapor imagery, was currently translating eastward over the
Mogollon Rim. Moist, isentropic ascent, while plentiful across the
Desert Southwest (per the 12Z RAOBs at FGZ and NYL), becomes
increasingly scant along the leeward side of the southern Rocky
Mountains and into W TX. This shortwave perturbation will eject over
W TX after 00Z, with high-based LCL/LFCs becoming elevated following
the cessation of vertical mixing. Brief downpours will be possible,
with any potential for strong gusts curtailing quickly as parcels
become elevated. NBM has caught onto this scenario, and PoPs were
tweaked and added through 09Z Tuesday morning, with the potential
for lightning waning shortly after 05Z/midnight CDT. Virga showers
may linger through sunrise as the shortwave perturbation finally
ejects east-northeastward into the central Great Plains.
During the early morning hours Tuesday, cold-frontogenesis will be
underway across eastern CO, as the aforementioned shortwave trough
digs into the central Rocky Mountains and begins to eject into the
western Great Plains. Convective-reinforcement of this front is also
forecast to occur, which in combination with the nocturnally-cooled
airmass, will accelerate its southward progression, with the front
moving into the CWA prior to sunrise. A brisk, northerly breeze will
accompany the passage of the front, although pressure tendencies are
expected to slacken as the cold front moves southward and eventually
stalls in the Permian Basin. The weakening, post-frontal fetch will
result in a wide range in high temperatures Tuesday, with at least a
15 degree temperature gradient forecast from northwest-to-southeast
across the CWA. Highs were adjusted to align with the recent MOS
output, which reflects the cooler side of the guidance, but highs
may need additional tweaking. Storm chances are set to return
Tuesday afternoon, primarily across the Rolling Plains, as low-level
convergence is maximized along the warm sector tongue of theta-e
advecting towards the stalling front.
Scattered, high-based storms, potentially in the form of loosely-
organized clusters, are forecast to develop across portions of the
Rolling Plains. Locally strong, to perhaps a severe-caliber wind
gust or two, will be possible due to the well-mixed sub-cloud layer,
with LCL/LFCs near 700 mb. Marginally-severe hail may occur within
the organized clusters as the base of the trough emerges over W TX
and lengthens mid-level hodographs, favoring the formation of weak,
mid-level mesocyclones. The coverage of storms will become more-
isolated coverage farther west onto the Caprock, and it is possible
that the Caprock is bereft of any storms due to weakening theta-e
advection and convergence before chances improve heading into
Tuesday night.
Sincavage
&&
.LONG TERM...
(Tuesday night through next Sunday)
Issued at 1230 PM CDT Mon Sep 22 2025
By sunset on Tuesday, light northeasterly surface flow will be in
place across the entire forecast area in the wake of the initial
cold front, with the corresponding surface trough axis progged to
stretch from NE OK southwestward over the Red River and into the
Permian Basin. Aloft, a sharp mid/upper level trough and associated
vorticity maxima initially over CO will steadily but slowly shift
eastward into the plains overnight into early Wednesday, and
although flow aloft will remain nearly zonal over our area, this
evolution will focus fairly strong forcing for ascent over the South
Plains and Permian Basin Tuesday night through early Wednesday.
Initially, this will allow scattered storms to continue over the
southeastern Rolling Plains near the remnant frontal zone during the
evening hours Tuesday. Later during the overnight period, most
guidance indicates a secondary frontal push descending southward
through the TX Panhandle which is expected to be the focus for an
additional round of showers and thunderstorms which will persist
through early Wednesday morning. This second round of precipitation
may be more widespread than the earlier activity, aided by stronger
large-scale ascent associated with the favorable location of an H5
jet streak just to our north. At this time the highest shower and
storm chances overnight look to be over southern portions of the
South Plains and Rolling Plains where a few downpours are possible,
with lesser rain chances and lower rain totals farther north. Rain
chances quickly come to an end by late Wednesday morning as a much
drier mid/upper level airmass spreads overhead, through a continued
northerly breeze and suppressed sfc-500mb layer thicknesses will
result in a relatively cool day with most locations only seeing
highs in the 70s to low 80s on Wednesday afternoon.
For the second half of this week, model consensus suggests that a
weak omega blocking pattern will develop with relatively low
amplitude ridging aloft present between deep troughing lingering
over the eastern CONUS and a cutoff low over SoCal. Dry weather is
therefore favored over our area for the rest of the work week, with
the gradual eastward expansion of the ridge also resulting in a
steady warm up and return to above normal temperatures by Friday and
Saturday. Forecast confidence decreases thereafter as the SoCal low
begins to open and drift eastward with flow aloft likely to turn
southwesterly by Sunday, if not before. Predictability with these
types of pattern evolutions is very low at this lead time, but this
could ultimately bring low rain chances back to mainly western zones
over the weekend and early next week.
&&
.AVIATION...
(18Z TAFS)
Issued at 1230 PM CDT Mon Sep 22 2025
VFR next 24 hours. Breezy, southwesterly winds at KLBB and KPVW
will diminish this evening while backing towards the south. Low
chances for -SHRA or TSTMs are forecast for KLBB and KPVW after
23/00Z, but confidence is too low to warrant a mention in this TAF
cycle, as coverage will be limited. A cold front will move in from
the north during the morning hours Tuesday, with northerly winds
briefly becoming breezy before tapering off by the afternoon.
Sincavage
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...09
LONG TERM....30
AVIATION...09

NWS LUB Office Area Forecast Discussion