Pep, Texas Weather Forecast Discussion

744
FXUS64 KLUB 120541
AFDLUB
Area Forecast Discussion
National Weather Service Lubbock TX
1241 AM CDT Fri Sep 12 2025
...New SHORT TERM, LONG TERM, AVIATION...
.KEY MESSAGES...
Updated at 1236 AM CDT Fri Sep 12 2025
- Thunderstorms will return this weekend, with heavy rain and
   flash flooding possible Saturday night to the west of I-27.
- A few storms may be severe Saturday night, with damaging wind
   gusts possible.
- Storm chances will linger into Sunday, with benign weather
   heading into next week.
&&
.SHORT TERM...
(Today and tonight)
Issued at 1236 AM CDT Fri Sep 12 2025
03Z upper analysis reveals a well-defined cyclone embedded within an
amplifying, positively-tilted trough over the Great Basin. This
cyclone extends through 200 mb, with the high-level vortex rotating
over the Owyhee Mountains. An intense pair of jetlets were rounding
its base, with nearly 100 kt at 250 mb translating northeastward
across the Great Basin atop a belt of 40 kt flow at 500 mb. Farther
east, the mid-level center of the subtropical ridge was rotating
over central N TX. This ridge will continue progress eastward into
the Mississippi Alluvial Plain throughout the next 24 hours, as the
concavity of the incoming trough increases as it begins to emerge
over the Intermountain West.
The surface pattern remains relatively similar to Thursday, with a
diffuse trough bisecting through the CWA based on WTM data. However,
winds will become breezier Friday afternoon due to the strengthening
isallobaric response associated with cyclogenesis in eastern CO, as
the leading edge of the jetlets will begin to nose into the High
Plains region and induce greater pressure falls. Vertical mixing
heights will ascend to near 700 mb by peak heating, although high
temperatures will be a couple of degrees cooler than the past few
days. Highs will range from the upper 80s near the NM state line and
into the middle 90s in the Rolling Plains. Breezy conditions are
expected to last into the overnight hours, resulting in slightly
warmer low temperatures beneath increasing cirrostratus.
Sincavage
&&
.LONG TERM...
(Saturday through Thursday)
Issued at 1236 AM CDT Fri Sep 12 2025
The shortwave trough to the west will be neutrally-tilted Saturday,
with the closed low also eroding and eventually opening as it
rotates east of the Great Basin. At the surface, the large-scale,
isallobaric response will intensify; and a stiff, southerly breeze
expected by Saturday afternoon, with winds between 15-20 mph across
the entire CWA. Winds will gradually back to the southeast towards
the evening hours from ongoing cyclogenesis to the northwest of the
CWA and as the leading shortwave perturbation ejects into the Great
Plains. Moist, isentropic ascent will be vigorous as the monsoonal
plume gradually shifts eastward towards the CWA, and it appears that
the bulk of the moist ascent will arrive during the late-afternoon
and evening hours as the trough becomes negatively-tilted. NBM PoPs
were removed for the morning hours Saturday through 18Z/1 PM CDT,
and trimmed to the west of the I-27 corridor for the afternoon.
Storm chances are set to increase quickly Saturday evening as the
monsoonal plume shifts eastward and as the Pacific cold front nears
the Mescalero Escarpment. Steering flow will be oriented towards the
southwest at around 30 kt, with a corridor of impressive IVT values
nearing 400 kg/m/s advecting near the NM state line Saturday night
into Sunday morning, along with PWATs exceeding the 99th percentile
late Saturday night within the monsoonal plume. Frontal-parallel
Corfidi vectors will favor the potential for training storms,
especially to the west of the I-27 corridor, which is where the
greatest concentration of storms will be before the low-level jet
veers. Storm chances will lessen with eastward extent into the
Rolling Plains during the nighttime hours Saturday into Sunday
morning, as NWP guidance is in considerable agreement on a narrow
channel of monsoonal moisture evolving with this system given its
quick progression and modulation into a negatively-tilted trough as
it pivots into the central Great Plains by Sunday morning. However,
a couple of swaths of locally heavy rainfall will be possible into
the Rolling Plains through the predawn hours Sunday. To the west of
the I-27 corridor, it appears that several swaths of heavy rainfall
will be possible through Sunday morning, especially for locales near
the NM state line in closer proximity to the Pacific cold front.
Negatively-tilted troughs typically have a fast progression when
ejecting into the Great Plains, and the base of the trough is
forecast to pivot from the Mogollon Rim to the NE Sandhills within
24 hours (Saturday night to Sunday night). Isentropic descent will
be advecting over the region Sunday, but with the Pacific front
gradually weakening, a few lingering storms will be possible across
portions of the CWA Sunday. NBM PoPs were lowered to 20-percent (or
a slight chance) for Sunday afternoon, as increasingly confluent
flow aloft on the backside of the attenuating trough atop the
convectively-overturned airmass will keep coverage widely-scattered
at best. Thereafter, restoration of a low-amplitude, subtropical
ridge will govern benign weather through the early and middle part
of next week. Global NWP guidance continues to converge on the
placement of the development of a weakly cyclonic gyre over the
northern Rocky Mountains, which will keep the CWA bereft of any
shortwave troughing until at least the end of next week.
Sincavage
&&
.AVIATION...
(06Z TAFS)
Issued at 1236 AM CDT Fri Sep 12 2025
VFR conditions are expected through the TAF period.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...09
LONG TERM....09
AVIATION...01

NWS LUB Office Area Forecast Discussion