Pettit, Texas Weather Forecast Discussion

459
FXUS64 KLUB 111107
AFDLUB
Area Forecast Discussion
National Weather Service Lubbock TX
607 AM CDT Thu Sep 11 2025
...New AVIATION...
.KEY MESSAGES...
Updated at 606 AM CDT Thu Sep 11 2025
- Dry and hot weather will continue through Friday.
- Thunderstorm chances continue to increase for this weekend.
- Heavy rain is possible Saturday night into Sunday morning.
&&
.SHORT TERM...
(Today and tonight)
Issued at 1233 AM CDT Thu Sep 11 2025
In the mid/upper-levels, a well-defined cyclone continues to rotate
over the Great Basin, with an amplifying, subtropical ridge becoming
centered over the Great Plains. To the east, a shortwave trough is
meandering over the Rust Belt, and is slow to move due to the Azores
High expanding across the entire North Atlantic, resulting in a
block-like pattern over the Lower 48. Persistence forecasting has
been applied area-wide for Thursday, as the upper air and surface
patterns are essentially a carbon copy of Wednesday. Expect mixing
heights to peak near 700 mb before encountering the mid-level
subsidence layer, and when combined with full insolation, highs will
reach the lower-middle 90s once again across the CWA. Cyclogenesis
near the Palmer Divide will also maintain the breeze, which will
back to the southeast by Wednesday afternoon. After the cessation of
vertical mixing, winds will diminish and veer southwestward in
response to the effects of daily cyclogenesis, with similar low
temperatures Thursday morning similar to the prior mornings.
Sincavage
&&
.LONG TERM...
(Friday through Wednesday)
Issued at 1233 AM CDT Thu Sep 11 2025
Thunderstorm chances continue to increase for this weekend, with the
highest chances across the Caprock on Saturday. At the beginning of
the period, the mid/upper-levels will feature a highly amplified
trough over the western U.S., and the closed low over the Great
Basin is forecast to open as an intense pair jetlets at 500 mb and
250 mb round its base. There is considerable agreement among the
global NWP guidance on this synoptic evolution occurring, especially
as a negatively-tilting trough, with a well-defined PV anomaly
embedded within, digs into Cascadia in the wake of the anticyclonic
wave breaking event over far northern Canada and into the Arctic
latitudes. The respective positive momentum fluxes will allow the
well-defined cyclone currently over the Great Basin to attain a
neutral-tilt by Friday night as it begins to eject towards the
central and southern Rocky Mountains. Farther east, the subtropical
ridge will continue shifting eastward, with its apex emerging over
the Osage Plains into the Upper Midwest. The breaking wave event
will be directly involved with storm chances this weekend, as the
southern-stream train of cyclones will be slow to move, which is
typical following the completion of anticyclonically-breaking wave
events. As a result, gradient winds will become breezier Friday due
to stronger cyclogenesis in eastern CO beneath the ejection of the
leading shortwave trough. The respective geopotential height falls
will also result in slightly cooler, though still very warm, highs
area-wide Friday afternoon.
By Saturday, the sharply cyclonic, shortwave trough is forecast to
pivot over the southern Rocky Mountains, with the 250 mb and 500 mb
jet streaks near 90 kt and 40 kt, respectively, rounding the base by
the afternoon hours. Flow throughout the cloud-bearing layer will
increase to around 40 kt, and the southwesterly orientation to the
flow throughout the steering layer is forecast to advect impressive
IVT values between 400-500 kg/m/s in congruence with PWATs exceeding
the 99th percentile Saturday night. Intense, high-level divergence
will occur as the shortwave trough becomes negatively-tilted and
ejects into the south-central or central Great Plains, with the
Pacific cold front moving towards W TX. Vigorous, moist, isentropic
ascent throughout the deep-layer theta surfaces, aided by the
effects of frontogenetical forcing, should generate scattered to
potentially numerous storms, which may become organized into a MCS
as a compact vorticity lobe rotates through the base of the trough
and ejects over the High Plains. A heavy rain event is possible
Saturday night into Sunday morning for portions of the CWA, with the
potential for some strong to locally severe-caliber storms early on
in the convective episode. NBM PoPs have increased from the previous
assessments, with 60-70 percent PoPs delineated primarily across the
Caprock. There was a consideration in reducing PoPs to 50 percent,
but the superposition of the synoptic features suggests otherwise;
and in fact, it will not be surprising to see PoPs increase hereon
out as the weekend nears. Mesoscale details remain nebulous at this
time; however, the background environment appears favorable for the
potential of multiple swaths of heavy rainfall Saturday night into
Sunday morning, especially for areas nearest the stalling front.
Negatively-tilted troughs typically have a quick progression
relative to positively-tilted troughs. Ergo, conditions should begin
to improve by Sunday, with more-isolated or widely-scattered storms
forecast for portions of the CWA Sunday as the stalled Pacific front
begins to weaken. Of course, storm chances Sunday will ultimately be
dictated by the vigor and time-scale of the overnight convective
event. Thereafter, global NWP guidance continues to indicate the
potential for a gyre-like pattern to the cyclonic flow to evolve
over the western U.S., but it appears that a dearth in storm chances
will follow as the bulk of the gyre remains displaced well to the
northwest of the CWA. Near-seasonal temperatures are forecast by
next week, with storm chances possibly returning late next week.
Sincavage
&&
.AVIATION...
(12Z TAFS)
Issued at 606 AM CDT Thu Sep 11 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