794
FXUS64 KSJT 011752
AFDSJT

Area Forecast Discussion
National Weather Service San Angelo TX
1252 PM CDT Wed May 1 2024

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 407 AM CDT Wed May 1 2024

...Say "Hello" May... Another round of severe storms expected
this afternoon into tonight...

A segmented line of storms is expected to affect most, if not
all, of our forecast area this afternoon and tonight.

Currently in the upper levels, our flow is becoming increasingly
southwest as an upper level trough moves into the western CONUS.
Later this afternoon and evening, a mid/upper level shortwave will
move over the area in the southwest flow. As the trough
approaches, cooler temperatures aloft will allow for mid level
lapse rates in the 8C/km range by late afternoon. Bulk shear
values from 0-6km are expected to range between 20 and 35 knots.
At the surface, our winds will respond to lee surface troughing
induced by the approaching shortwave, becoming gusty out of the
south to southeast. This will help to maintain warmer than normal
temperatures and abundant low level moisture, and a dryline will
sharpen to the west of our CWA border. Surface based CAPE values
should increase into the 2500 to 3500 J/kg range by mid/late
afternoon.

Expect initial scattered storms to develop over the Trans Pecos
and Stockton Plateau areas to our west by around 3 PM. These
initial storms will likely be able to rotate and quickly
strengthen to severe levels. As additional development occurs both
north and south, upscale growth into one or more QLCS line
segments near or just inside our western CWA border is expected,
with these lines picking up speed as they move east through our
area. The initial storms are expected to have large to very large
hail, and damaging wind gusts. As the storms evolve into line
segments and move east, severe wind gusts and large hail will be
the main hazards, but a few tornadoes will also be possible. Some
of the storms will contain heavy rainfall, so localized flash
flooding will also be possible. These storms are expected to move
out of our area between 3 AM and 6 AM Thursday morning.

Look for highs in the mid to upper 80s, and lows tonight in the
low to mid 60s.

&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 407 AM CDT Wed May 1 2024

The active pattern will continue into Thursday. The dryline is
expected to push east into our central counties by the afternoon
timeframe. At the same time, a cold front will be sagging south
through the Red River Valley and into northern portions of our
area. This means that chances for showers and storms will
generally be limited to areas south of the cold front and east of
the dryline (current indications show this as areas east of
US-83). These areas will be very unstable with MLCAPE values by
21Z between 2500-3500 J/kg. Shear will be modest in the 25-35kt
range and mid level lapse rates will be decent around 8 deg C/km.
Current CAMs are a bit anemic in regards to development in our
area during the Thursday afternoon/evening timeframe but if storms
can develop given the lift from the two boundaries, it is a good
bet that they could become severe. The main threats would be large
hail and damaging downburst winds given DCAPE values just around
1000 J/kg in the warm sector. Right now, the Storm Prediction
Center has the eastern 2/3 of our area in their Day 2 Marginal but
if increased confidence in development occurs, we wouldn`t be
surprised if this was upgraded in future outlooks. Temperature
wise, areas behind the dryline will see highs in the low to mid
90s as skies clear and downsloping west/southwest winds increase.
Further east. increased cloud cover and chances for storms will
hold temperatures in the mid to upper 80s.

Chance for rain Friday through Sunday will be largely dependent
on the actions of the aforementioned cold front. Current
indications are that it would stall out in the Central Texas
vicinity for much of the weekend. Ample moisture across the region
and weak upslope flow will create chances for showers through
this timeframe. Have capped shower/storm chances for Friday and
Saturday in the high-end chance category. It`s not clear if this
activity would be scattered or more widespread given the weak flow
across the region. In any case, chances for rain are highly
dependent on the front and, as such, have plenty of uncertainty
attached to them. Rain chances generally increase across the area
for Sunday as upper level support increases ahead of the next
large upper trough, increasing southwest flow overhead. Rain
chances generally come to an end by late Sunday night. WPC QPF
totals at this point show a fairly widespread 1-3 inches across
the area through Monday morning, though given the nebulous nature
of the rain chances and overall forecast, this should be taken
with a grain of salt for the time being. Temperatures will
generally cool through the weekend with highs in the mid 80s to
low 90s Friday, dropping into the upper 70s to low 80s by Sunday.

Confidence is increasing in a significant warm up for next week.
Long- range models have come into better agreement with how to
handle the upper trough and generally track it north of the area.
A dryline is expected to work its way into the area Monday and
make little retreat overnight into Tuesday. As such, it surges
even further east Tuesday, bringing strong west/southwest winds
into the area. At the same time, the 850 mb thermal ridge is also
expected to expand east into our area. Together, this will allow
for temperatures to climb back into the upper 80s to low 90s for
Monday with widespread 90s to near 100 by Wednesday. CPC has
already included our area in their 8- 14 day Slight Risk for
excessive heat area. So, unfortunately, all signs are pointing to
the heat being on for much of next week.

&&

.AVIATION...
(18Z TAFS)
Issued at 1242 PM CDT Wed May 1 2024

Mainly looking at VFR ceilings around 5K feet this afternoon,
with south to southeast winds gusting 20 to 25 knots. Scattered
thunderstorms are expected to develop along the dryline to our
west late this afternoon and move east across the terminals
through the evening hours. Some of the storms may become strong
to severe, with damaging winds and hail the main hazards. Will
maintain TEMPO groups at the terminals for convection based on
latest high resolution model data. Convection will end from west
to east between 05Z-07Z. Expect MVFR ceilings to develop across
the terminals late tonight into Thursday morning, with some
possible IFR ceilings across the southern terminals after 10Z. For
now, will keep ceilings MVFR due to lower confidence in IFR
conditions

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene     64  90  62  86 /  70  20  20  30
San Angelo  64  93  65  91 /  60  10   0  30
Junction    67  90  69  92 /  60  20  10  30
Brownwood   64  86  66  85 /  80  30  20  20
Sweetwater  64  91  62  86 /  60  10  10  30
Ozona       65  92  65  89 /  60  10   0  30
Brady       65  86  67  86 /  70  30  10  30

&&

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

$$

SHORT TERM...20
LONG TERM....50
AVIATION...24