965
FXUS64 KLUB 281746
AFDLUB

Area Forecast Discussion...RESENT
National Weather Service Lubbock TX
1246 PM CDT Thu Aug 28 2025

...New KEY MESSAGES, SHORT TERM, LONG TERM, AVIATION...

.KEY MESSAGES...
Updated at 1246 PM CDT Thu Aug 28 2025

 - Slight chance of showers and thunderstorms this evening, mainly
   over the Rolling Plains.

 - Storm chances continue Friday and through the weekend, with the
   potential for heavy rain leading to flash flooding concerns.

 - Friday night and especially Saturday night have the greatest
   potential for flash flooding, and some storms may be severe.

&&

.SHORT TERM...
(This evening through Friday)
Issued at 1246 PM CDT Thu Aug 28 2025

A mid-level ridge combined with WSW flow will bring warm and dry
conditions to the area this afternoon. Highs will be a few degrees
warmer than yesterday, topping out in the mid-to-upper 90s outside
of slightly cooler temperatures to the northwest. An embedded
shortwave will track through the area this evening. NW flow aloft
along with surface cold front will lead to chances of showers and
thunderstorms moving northwest to southeast this evening, mainly
over the Rolling Plains. Both synoptic models and CAMs have
consistently indicated this since yesterday. Severe weather is
unlikely, however some storms may produce periods of heavy rain and
brief gusty winds. The front will be largely moved out after sunset,
with surface winds switching easterly in its wake. Lows will again
remain mild with these winds remaining elevated near 10 mph
overnight along with likely low cloud cover developing around
sunrise given the moist easterly flow and an approaching upper ridge
to the west. Skies will clear through the day as the ridge axis
moves overhead, with the easterly winds keeping highs a bit lower
than today, ranging from the mid 80s to near 90. A more potent
embedded wave will approach from the west by late-afternoon.
Moisture parameters remain high, and as such CAMs are generally in
agreement on a line of storms developing near the TX/NM border and
tracking eastward through the evening. More details in the long-term
section.

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 1246 PM CDT Thu Aug 28 2025

Thunderstorm chances are expected to increase quickly after dusk
Friday as a well-defined shortwave perturbation translating through
the apex of the deamplifying ridge ejects over W TX. The potential
for widespread storms exists, possibly in the form of an organizing
line and/or MCS, as it propagates along the thickness gradient
oriented over the CWA. The 250 mb jet streak will still be
anticyclonically-curved, with 40-45 kt of 250 mb flow nosing
southward over W TX as the ridge deamplifies, resulting in a net
increase of high-level divergence. As the belt of deep-layer flow
begins to intensify, the magnitude of downshear Corfidi vectors will
increase accordingly, or to around 30 kt. Should the convective
clusters organize into a MCS, then a wider footprint of potentially
heavy rainfall will occur. However, downshear propagation vectors
near 30 kt would nix any potential for training, but the related
geopotential height falls from the deamplifying ridge will allow the
depth and size of CAPE to grow, with forecast soundings indicating
upwards of 2,000 J/kg for most-unstable parcels. The combination of
the taller, skinny CAPE profiles; increasing cloud-layer shear, and
PWATs potentially exceeding the 99th percentile (per the 30/00Z
sounding climatology from WFOs AMA and MAF) amidst warm-cloud depths
near 14 kft AGL will lead to efficient rainfall within the organized
cores.

Rain rates between 1-2"/hr will be common with the strongest storms,
but the overall extent of flash flooding will be curtailed by the
mean convective movement near 30 kt to the southeast. The potential
for strong-to-severe-caliber wind gusts will also exist during the
late evening hours Friday before storms eventually become rooted
above the decoupling boundary-layer during the early morning hours
Saturday. Regardless if a MCS forms or if the clusters remain
loosely-organized, the background environment will be favorable for
the maintenance of storms and the attendant flash flooding risk
throughout the nighttime hours and into the predawn hours Saturday,
with storms eventually clearing to the south and east of the CWA
Saturday morning. It remains a bit unclear on whether or not
regenerative showers, and possibly storms, linger into the afternoon
hours Saturday, but that potential could be realized if a MCV forms
and interacts with residual outflow boundaries in the wake of the
overnight system. A reduction in PoPs for Saturday afternoon may be
necessary in upcoming forecast cycles before chances reload by the
nighttime hours into Sunday morning. The overcast is expected to
slowly erode towards peak heating Saturday, with highs ranging from
the lower-middle 80s area-wide. Convectively-contaminated surface
winds are also forecast to restore towards the southeast by the
afternoon hours, as the quasi-stationary front is forecast to be
positioned slightly west and south of the CWA.

There is an increasing potential for a heavy rain event to evolve
across W TX Saturday night. In the mid/upper-levels, the subtropical
ridge will continue to deamplify, with its center rotating into
central TX, as a well-defined shortwave trough digs into the central
Rocky Mountains. This will modulate the concavity of the attendant
jet streaks arcing around the apex of the subtropical ridge into a
more-quasi-zonal state, and shift the right-entrance region of the
250 mb jet streak directly over the CWA. The emergence of the
shortwave trough over the central Rocky Mountains will cause the
belt of mid-level flow to veer towards the northwest, with an
expectation for a vorticity lobe to rotate southeastward over the
Raton Mesa and into W TX Saturday night. NAEFS/ENS, in addition to
numerous forecast soundings and other NWP guidance, continue to
indicate a reservoir of PWATs near or in exceedance of the 99th
percentile, or 2-3 standard deviations above the climatological
mean. The influx of anomalous moisture content will have already
been in place, but the strengthening of a backing low-level jet in
response to the convectively-augmenting vorticity lobe is forecast
to facilitate a greater potential for heavy rainfall across portions
of the CWA Saturday night into Sunday morning.

The risk for flash flooding will increase accordingly Saturday
night, as rain rates between 1-2"/hr will once again accompany the
strongest storms, and it is possible that rain rates upwards of
3"/hr come to fruition. The big question that remains is the start
time of this event, and the thinking has been leaning towards the
late-evening hours after sunset, especially as the airmass Saturday
gradually recovers from convective overturning. This will continue
to be ironed out over the next 24 hours. Regardless, there is an
increasing potential for an overnight flash flooding event across
portions of the CWA; however, the mean convective movement of the
clusters and/or MCS will be similar to the prior night, or to the
southeast near 30 kt along the thickness gradient of the deamplified
ridge. A more-southward propagation is possible, but the potential
for back-building and prolonged, heavy rainfall will be mitigated by
the enlarged downshear propagation vectors. Cooler temperatures will
follow heading into Sunday, with daily chances for storms forecast
each day through next week as the subtropical ridge begins to
amplify over the Intermountain West, along with a gradual warm-up.

Sincavage

&&

.AVIATION...
(18Z TAFS)
Issued at 1246 PM CDT Thu Aug 28 2025

Generally light westerly winds will veer out of the NE this evening.
There is a slight chance of thunderstorms this evening as well,
however any storms that develop should remain south and east of all
terminals. KLBB would have the greatest chance, but confidence is
not high enough to include in the TAF. MVFR CIGs will persist at all
sites from around midnight through mid-morning Friday. Brief IFR is
possible near sunrise, particularly at KCDS.

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...19
LONG TERM....09
AVIATION...19