094
FXUS64 KLUB 201119
AFDLUB

Area Forecast Discussion
National Weather Service Lubbock TX
619 AM CDT Fri Sep 20 2024

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 240 AM CDT Fri Sep 20 2024

Current water vapor imagery depicts the upper level ridge and dome
of high pressure positioned over southwestern Texas. By this
afternoon the upper level ridge is expected to track southeastward
as the upper level low off the southern CA coast begins to track
into the desert southwest region this afternoon. Moist southerly
winds from the surface to H7 will help influence dewpoints once
again in the upper 50s to mid 60s this afternoon. In addition,
mid-level Pacific moisture wrapping around the center of the high
pressure system will also creep into portions of the far
southwestern Texas Panhandle this afternoon. Although instability
remains rather weak, a few isolated showers will be possible
across northwestern portions of the FA as a few perturbations in
the flow aloft interact with the present moisture. Shower activity
remains limited, with the best chance of areas seeing
precipitation being confined to areas to the north and west of the
FA where the better moisture looks to reside.

A surface low well to our north, along with the incoming trough to
our west will influence breezy southerly conditions today around 10
to 20 mph. These southerly winds in combination with similar
thickness values compared to yesterday, and relatively clear skies
will lead to temperatures in the 90s to lower 100s. Meanwhile,
tonight will also be similar to previous in the 60s to near 70s
which is still about 10 degrees above normal.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 240 AM CDT Fri Sep 20 2024

Very fitting for the changing seasons this weekend is a welcome
pattern change that promises cooler and wetter weather through the
first half of next week. Saturday opens with a filling upper low
in AZ that proceeds to minor out over the central plains by Sunday
evening. Pressure falls in NM for much of the day on Saturday
will tug unseasonably rich gulf moisture throughout eastern NM
ahead of a dryline and approaching upper low. PWATs throughout the
moist sector are progged between 130 and 200 percent of normal -
highest just west of the TX/NM border. Models continue to keep the
upper low on the slower side of earlier forecasts which favors
dry conditions for all but our W-NW zones for much of the day.
Even though the strongest upper divergence stays well to our
north Saturday and Saturday night immediately downstream of the
upper low, models agree nicely in an upper jet axis tracking from
the western South Plains into the eastern TX Panhandle which (no
coincidence) aligns nicely with their QPF distribution. NBM`s PoPs
were tweaked to better fit this signal and heavy rain was inserted
across our N-NW zones Saturday afternoon and evening where a
longer residence time of lift and deep saturation could result in
an inch of rain in some locales. Severe storm potential meanwhile
should favor eastern NM with some of this bleeding over and into
our western counties by Saturday evening as ascent ramps up. As
earlier discussions cited, soundings still favor downbursts as the
primary severe threat.

As the upper low tracks over CO Saturday night into Sunday, a
healthy cold front will drop into the TX Panhandle before sweeping
across the CWA Sunday afternoon. Given the amount of CAA with
this front, it wouldn`t be surprising to see FROPA speed up some
in later forecasts. Following a lull in PoPs late Saturday night,
good rain chances return Sunday afternoon - this time favoring all
but our far W-NW zones which will reside west of an impressive
moist axis. Heavy rain potential is again in the offing for
Sunday, especially off the Caprock where PWATs flirt with 2
inches. Severe prospects are less than Saturday as deep convection
should quickly become undercut and more anafrontal in nature
which typically favors training along with some flooding potential
in this case.

Markedly drier north winds Sunday night and Monday within surface
ridging will shove rain chances to our south until return flow
ensues Monday night ahead of a trough diving south along the
Continental Divide. Confidence is improving in another round of
healthy PoPs for Tuesday thanks to rich moisture pooling over the
area. The GFS and ECMWF diverge with this trough/low by Tuesday
night, yet a generous field of saturated isentropic ascent is
still favored in our area for most of Tue and Tue night. Left
NBM`s PoPs intact but Tuesday`s high temps were nudged lower to
account for thicker clouds and improved precip chances.
Thereafter, confidence in the upper pattern craters as either
ridging (ECMWF) or a nearby low (GFS) are over West TX. Until
model clarity improves, left NBM`s low PoPs and moderating temps
in check for Wed and Thu.

&&

.AVIATION...
(12Z TAFS)
Issued at 617 AM CDT Fri Sep 20 2024

Southerly winds are expected to become breezy this afternoon
before diminishing after sunset. VFR conditions are expected to
prevail.

&&

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

$$

SHORT TERM...12
LONG TERM....93
AVIATION...12