667
FXUS64 KSJT 301920
AFDSJT

Area Forecast Discussion
National Weather Service San Angelo TX
220 PM CDT Tue Apr 30 2024

...New SHORT TERM...

.SHORT TERM...
(This evening through Wednesday)
Issued at 218 PM CDT Tue Apr 30 2024

A little bit of an all or nothing forecast for later this
afternoon and evening across West Central Texas. Unstable air mass
with CAPE values climbing above 2500 J/KG, but a weak cap still in
place. Not much of a convective focus other than relatively weak
convergence along a developing dryline. And not a lot of upper
level support with weak ridging in the mid and upper levels. All
this means is that storm initiation is a question, but if a storm
can develop that storm may be enough to weaken the cap and allow
for  storms to develop in a small convective cluster. Which is
exactly what several of the high resolution CAMs are showing,
while other models are showing little convection and isolated
storms at best.

Will go with a little bit of a consensus and expand the area of
storms to cover more of the Concho Valley and Heartland, with a
little higher POPs across the Big Country where CAMs are showing a
little more possibility of one of those convective clusters. Given
the instability, there is a potential for a few of these storms to
reach severe levels, although only very modest shear values may
make it more difficult for these storms to not outflow themselves
and may put a limit on just how severe the storms may be. SPC has
a marginal risk and that seems like a perfectly good forecast.

Not going to talk a lot about the severe weather potential for
tomorrow. Will let the long term AFD handle it since most of it
will be after 00Z. But will say that the air mass doesn`t change
very much, but given a much better defines shortwave approaching
to provide better shear and a sharper boundary, storms look more
likely.

&&

.LONG TERM...
(Wednesday night through next Tuesday)
Issued at 212 PM CDT Tue Apr 30 2024

The dryline is forecast to remain well west of our area on
Wednesday, only advancing east into the Trans-Pecos region and
Permian Basin. East of the dryline, good instability will develop,
with SBCAPE values of 3K to 4K J/KG. Shear will be modest, with 0-6
KM Bulk Shear values of 30 to 35 knots. A weak upper level shortwave
trough is forecast to track across the region late Wednesday, which
should result in the development of showers and thunderstorms along
the dryline to our west. This activity will then track east across
much of the forecast area through the evening hours. A few strong to
severe thunderstorms are possible, with large hail and damaging
winds being the main hazards, although a tornado is also possible.
Initially storms should be discrete with supercells most likely, but
as the activity advances east, the cells might merge in to one or
more linear complexes. Rainfall amounts will likely range between
1/4 and 1/2 inch of rainfall, but amounts over 1 inch are possible
in any of the more intense storms. At this point, the highest rain
chances look to be across our eastern counties, where a more linear
mode in convection is expected versus our western counties where
more discrete cells are likely.

On Thursday, a dryline is forecast to advance east into our central
counties by mid to late afternoon. Meanwhile, a cold front will move
into the Big Country during the morning hours, then approach central
portions of the area by mid to late afternoon. Isolated to scattered
showers and thunderstorms will be possible during the afternoon and
evening hours, for those areas south of the front and east of the
dryline. This will confine PoPs to mainly our eastern counties.
Cooler temperatures and gusty north winds will filter in behind the
front. Expect overnight lows in the 60s. Highs on Friday will be a
few degrees cooler, in the upper 70s to mid 80s across the Big
Country to the mid to upper 80s elsewhere.

Slightly cooler temperatures are expected this Friday into the
weekend, with highs mainly in the 80s. PoPs this weekend continue to
be somewhat uncertain and will depend on exactly where the front
stalls and eventually how far north it lifts. At this point, PoPs
were kept mainly in the chance category, with the higher PoPs across
the Big Country. These may need to be adjusted on future shifts once
higher confidence is reached.

&&

.AVIATION...
(18Z TAFS)
Issued at 1213 PM CDT Tue Apr 30 2024

The MVFR cigs of the morning have largely lifted and are starting
to break up some, with most areas likely to see VFR conditions for
the remainder of the afternoon and evening. More low clouds are
likely to return overnight and VFR conditions will prevail again
by sunrise Wednesday morning.

Latest CAMs continue to show some support for some convection this
evening, although they vary widely in coverage. Right now it looks
like the best chances may be near KABI for a few hours around
sunset, with much more isolated activity farther south. Will
include a tstm mention up at KABI for a few hours but hold off
elsewhere until the chances look better.

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene     67  86  65  90 /  30  30  70  20
San Angelo  69  89  67  93 /  20  40  60  10
Junction    70  87  69  90 /   0  30  60  30
Brownwood   67  84  67  87 /  10  30  80  40
Sweetwater  68  87  65  91 /  20  40  50  10
Ozona       68  82  67  91 /  10  30  40  10
Brady       69  84  67  86 /  10  30  80  30

&&

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

$$

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