583
FXUS64 KSJT 180400
AFDSJT

Area Forecast Discussion
National Weather Service San Angelo TX
1000 PM CST Sun Nov 17 2024

...New AVIATION...

.KEY MESSAGES...

  - Strong to severe thunderstorms, heavy rain and flooding
    possible tonight into early tomorrow morning.

 -  Windy Conditions likely during the day Monday.

 -  Colder temperatures for the middle to latter part of the
    upcoming week.

&&

.SHORT TERM...
(This evening through tonight)
Issued at 101 PM CST Sun Nov 17 2024

Classic low instability but high shear event upcoming for West
Central Texas tonight.

Area radars continue to show an area of showers with mainly light
to briefly moderate rainfall across portions of the Permian Basin
and South Plains, just clipping the western portions of the
Concho Valley and Big Country. All indications are that this area
will become more widespread as we go through the remainder of the
afternoon and the evening hours, with POP chances going up into
tonight. Aloft, potent upper level low continues to move across
northern Mexico this afternoon.

Tonight, this upper low will move into West Texas Monday morning
and then eject into Kansas by noon Monday. Very strong wind fields
with this system, with 850 mb jet hitting 50+ knots, near 70 kts
at 700 mb, and 500 mb near 100 kts by late tonight moving across
West Central Texas. On the other hand, instability and lapse rates
will be weak, with CAPE values remaining mostly in the 500-1000
j/kg range. Thus, hail threat will be relatively limited. Wind
threat however will be the main issue, with any downdrafts from
these storms likely to pull down some of these higher winds aloft
down to the surface. Biggest threat area may be across the Big
Country where a little more coherent outflow boundary from the
storms may be able to produce a more widespread damaging wind
area.

Strong shear profiles (0-1k SRH of 250-400) means the tornado
threat is not zero either, with the possibility of a few QLCS
type spin-ups certainly possible. Again, the main threat area may
be across the Big Country closer to the actual surface low where
low level wind fields will be backed more than areas farther
south.

One last note, once the line gets completely developed (and this
may not be until midnight) storms will be kicking out across the
area very fast. Entire line will be shifting east as fast as
40+ mph, with the individual cells even a little faster. Fast
movement and overnight time period will mean that the public may
need to react to any warnings a little quicker than they might
normally do, since the weather may appear fairly quiet until
right before the storm arrives.

Finally, will leave the Flash Flood Watch in effect as is for now.
Main concern will continue to be across the northwest Concho
Valley into the central and western Big Country, where showers and
storms may become more widespread this evening before even the
main squall line moves into the area overnight. Plenty of moisture
in place and given that soils are still decently saturated from
the very heavy rainfall 3 weeks ago, the threat remains in place.
Farther south and east across areas that may see only the squall
line, threat is likely smaller just due to the fast movement of
the line itself.

&&

.LONG TERM...
(Monday through next Sunday)
Issued at 202 PM CST Sun Nov 17 2024

...Wind advisory 3 AM Tonight to 3 PM Monday afternoon...

60-70KT 700 mb wind max will be moving northeast through West Texas
early Monday morning. Strong southwest winds of 25 to 35 mph will
gust to 45 mph, with possibly 50 mph in higher elevations. A wind
advisory has been issued generally along and north of an Ozona...
Eldorado... Eden to Brownwood line from 3 AM to 3 PM. Wind
advisory was started a few hours early as some of the stronger
winds aloft may reach the surface, as a line of thunderstorms
moves through. Storms along/east of a Haskell to Abilene to
Junction line at 6 AM should be east of Brownwood and Saba by 9
AM. Winds should be falling by mid afternoon Monday as the upper
trough moves northeast, with winds dropping quickly towards
sunset.

Cooler temperatures in the upper 60s/lower 70s are in store Monday
and Tuesday, with lows in the 40s. Another cold front will move in
Tuesday night, bringing highs Wednesday in the lower 60s (Big
Country to mid 60s along I-10). Lows will be falling into the upper
30s Wednesday morning and mid 30s to 40 degree range Thursday
morning as surface high pressure settles over the central and
eastern Texas. There is the potential for a low spot or two to
briefly reach the freezing point in the valleys near Junction and
Saba Saba, where winds will be lightest. Most areas should stay
above freezing. Highs warm back up into the upper 60s/lower 70s
Thursday and mid 70s by next Sunday. No rainfall otherwise for the
rest of the week, with dry air at the surface and zonal flow
aloft.

&&

.AVIATION...
(06Z TAFS)
Issued at 955 PM CST Sun Nov 17 2024

Scattered showers and thunderstorms will affect the TAF sites,
mainly KSJT and KABI, over the next couple of hours. A line of
storms will move through the area between 07Z and 12Z. Strong
gusty winds and locally heavy rain are possible as the line moves
through. MVFR to IFR ceilings will develop at all sites early
Monday morning, with VFR conditions returning by mid to late
morning. Gusty south winds of 15 to 20 knots will become west to
southwest at 15 to 25 knots, with higher gusts. The gusty winds
will continue through much of the day Monday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene     54  69  48  70 / 100  20   0   0
San Angelo  52  70  45  72 /  90   0   0   0
Junction    54  72  45  76 /  90  30   0   0
Brownwood   57  70  46  73 / 100  60   0   0
Sweetwater  52  69  47  69 / 100   0   0   0
Ozona       51  70  45  71 /  90   0   0   0
Brady       57  70  49  73 /  90  40   0   0

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 6 AM CST Monday for Callahan-Coke-Fisher-
Haskell-Jones-Nolan-Shackelford-Sterling-Taylor-Throckmorton.

Wind Advisory from 3 AM to 3 PM CST Monday for Brown-Callahan-
Coke-Coleman-Concho-Crockett-Fisher-Haskell-Irion-Jones-Nolan-
Runnels-Schleicher-Shackelford-Sterling-Taylor-Throckmorton-Tom
Green.

&&

$$

SHORT TERM...07
LONG TERM....04
AVIATION...Daniels