-- Discussion containing changed information from previous version are highlighted. --
796
FXUS64 KSJT 221141
AFDSJT

Area Forecast Discussion
National Weather Service San Angelo TX
641 AM CDT Sun Sep 22 2024

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 342 AM CDT Sun Sep 22 2024

...Thunderstorms expected this afternoon through tonight...

Currently, an upper level low is located over CO, with southwest
flow over west central Texas. This low is expected to open into a
wave while slowly moving east into the central and southern plains
by Monday morning. This will maintain southwesterly flow over our
area. At the surface, a cold front is expected to move south into
our CWA by this afternoon, making its way through the rest of the
area by late tonight. Scattered to widespread thunderstorms are
expected to develop along and ahead of the cold front this
afternoon, and continue through most of the overnight hours.

With temperatures warming well into the 80s to lower 90s this
afternoon, combined with plentiful low level moisture
(precipitable water values near 2 inches), low levels will
destabilize ahead of the front. Mixed layer CAPE values are
forecast to be in the 500 to 1500 J/kg range during peak heating
hours. Deep layer shear values of 40 to 50 knots over the area,
combined with the instability will allow some of the storms to
become strong, with a few storms possibly severe. The main concern
with the storms will be wind gusts over 60 mph, but hail up to
the size of quarters will also be possible. After sunset,
instability will wane, and although storms may continue, the
concern for severe weather will diminish. The other concern will
be heavy rain and localized flooding with precipitable water
values near 2 inches.

Storms are expected to develop first over the Big Country along
the front, then spread southward over the rest of the area during
the afternoon and overnight hours as the front moves south.
Overall coverage should diminish late tonight, but isolated to
scattered activity will still be possible after midnight, mainly
south of Interstate 20.

&&

.LONG TERM...
(Monday through Saturday)
Issued at 449 AM CDT Sun Sep 22 2024

An upper level low pressure system will move north of our area
and then proceed east across the Plains on Monday. Then, another
strong low pressure system will move across the eastern portions
of the Great Plains on Wednesday. This will swing another cold
front into the area, which will keep temperatures a bit cooler for
the remainder of the work week. High temperatures look to be in
the upper 70s to middle 80s. This same system and the attendant
frontal boundary will also be supportive of another round of
rainfall across the area on Tuesday and Wednesday ahead of the
front. The Weather Prediction Center has placed west Central Texas
into another Marginal Risk (5% chance) of excessive rainfall
leading to flash flooding on Tuesday and Tuesday night. Rainfall
totals may be near 0.5" to 1" during this time frame with locally
higher amounts remaining possible. We will have to keep an eye on
this scenario for changes in the next day or two.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 640 AM CDT Sun Sep 22 2024

MVFR ceilings have moved into parts of the area, but are much less
extensive than model data suggested earlier. Will keep a mention
of low clouds in at KSJT and KJCT as a TEMPO group, but have
removed them from KBBD for now. Otherwise, no significant changes
from the previous forecasts for TSRA moving into the area later
today and tonight.
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene     91  59  75  62 /  60  80  30  20
San Angelo  93  62  76  63 /  50  80  40  20
Junction    92  66  82  65 /  10  40  40  10
Brownwood   91  64  78  64 /  30  60  40  20
Sweetwater  88  59  75  63 /  80  70  20  20
Ozona       89  63  77  64 /  30  70  40  20
Brady       91  64  78  64 /  20  50  40  20

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...20
LONG TERM....41
AVIATION...20