581
FXUS64 KSJT 021748
AFDSJT

Area Forecast Discussion
National Weather Service San Angelo TX
1248 PM CDT Thu May 2 2024

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 343 AM CDT Thu May 2 2024

Thunderstorm activity has moved east of the area, with just some
isolated showers left in the Brown County, and southern Concho
Valley areas. These showers are expected to diminish in the next
hour or two.

Southerly flow will reestablish itself in our area through the
morning hours. To our north, a cold front will move south toward
our region, and the dryline will sharpen up just west of our
forecast area. By this afternoon, as temperatures warm into the
mid 80s to lower 90s and combine with dewpoint values in the mid
to upper 60s, surface based CAPE will increase into the 3000 to
4000 J/kg range again. Deep layer shear is expected to be a bit
weaker today, with 0-6km shear values in the 20 to 30 knot range.
With instability values that high, the initial storms will once
again be able to quickly strengthen and be capable of producing
large to very large hail.

There is some uncertainty on whether or not storms will develop,
and if they do, where. CAMs are showing storms developing either
along the front north of a Sterling City to Brownwood line, or
farther south and west along the dryline near or just west of the
Concho Valley. Will have highest PoPs generally east of a
Sweetwater to Mason line, but will also have at least some Slight
Chance PoPs into the Concho Valley area as well.

Storms could persist into the late evening hours again, especially
east of an Abilene to Mason line, with storms expected to end
earlier to the west. Temperatures will again be in the mid 80s to
lower 90s for highs, with lows mainly in the 60s tonight.

&&

.LONG TERM...
(Friday through Wednesday)
Issued at 343 AM CDT Thu May 2 2024

Friday could see another round of dryline development. With our
area in continued southwest flow aloft and on the fringe of the
southern stream jet, guidance is indicating the potential for a
shortwave to pass overhead during the afternoon hours. This would
likely provide enough upper level support to see development off
of a quasi-dryline likely somewhere near our western CWA border.
Southeasterly surface winds through the day will help to moisten
the boundary layer across the area leading to MLCAPE values
between 2500-3500 J/kg. Shear will be similar to previous days in
the 25-35 kt range with mid level lapse rates right around 8 deg
C/km. SPC has the Day 2 Marginal ending just north of our area in
the Caprock, if guidance continues to trend the way it has with
the shortwave passage, would not be surprised if this is extended
further south in future updates. The main threats would likely be
large hail and damaging winds. Current indications are that these
storms would move off to the east fairly quickly with the threat
tapering off after midnight.

By Saturday, a frontal boundary is expected to stall just north
of our area. Storms will be possible along the front earlier in
the day, keeping rain/storm chances in play for northern areas of
the Big Country Saturday morning. However, as the boundary layer
heats up and destabilizes through the day, more diurnal activity
is expected to develop across the area with yet another potential
shortwave passing overhead. Later in the day, an easterly low
level jet is expected to develop, helping shower and storm
activity to become more widespread, potentially developing into an
MCS type feature. With ample instability in place and steep lapse
rates, some storms could become severe, especially across the Big
Country and western Concho Valley where the Day 3 Marginal Risk
for severe storms is located. As activity becomes more widespread
Saturday afternoon through Sunday morning, this looks to be the
best timeframe to see heavy rainfall leading to flash flooding. As
such, WPC has put the Big Country, Concho Valley, and Heartland
in their Slight Risk (Level 2 of 4) for excessive rainfall with
the rest of the area in Marginal (Level 1 of 4). The highest
rainfall totals will likely be in the Big Country, closer to the
frontal boundary. With the weak frontal boundary still in the
region for Sunday and southwest flow continuing aloft, we will see
continued chances for showers and storms through the day before
coming to an end overnight into Monday morning. High temperatures
through the weekend will generally stay in the upper 70s to 80s.

A large upper trough is expected to move north of our area during
the day on Monday. As a dryline pushes east into our area during
the day, upper level support may be strong enough to warrant a
chance of showers and storms across our northeastern counties
between 18-00Z. Better chances will stay well to our north though,
closer to the negatively tilted trough axis. Behind the dryline,
skies will begin to clear and winds will pick up out of the west.
This dry, downsloping air will help to warm temperatures into the
lower 90s for the Concho Valley and Northern Edwards Plateau.
Elsewhere should see highs in the mid to upper 80s. The dryline is
overall expected to make little retreat to the west overnight and
will push even further east on Tuesday and Wednesday. This should
keep our area dry and allow for temperatures to reach well above
average into the 90s, even the mid and upper 90s for areas south
of the I-20 corridor. CPC has our area highlighted in their 8-14
day Slight Risk for Excessive Heat for May 9-11 so unfortunately
it looks like the heat will be sticking around through the end of
next week.

&&

.AVIATION...
(18Z TAFS)
Issued at 1232 PM CDT Thu May 2 2024

Skies are clearing from west to east, lifting MVFR CIGs to VFR
over the next hour or so. Storms are possible later this afternoon
and overnight. Exact location of the storms is uncertain, KABI has
the best chance of seeing storms this evening, but the other sites
could have a nearby thunderstorm as well. Gusty winds, lighting,
and hail will likely accompany these storms. Low clouds will move
in overnight, dropping CIGs to MVFR and IFR.

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene     89  63  82  64 /  40  40  40  40
San Angelo  93  64  90  64 /  20  10  40  30
Junction    90  67  90  66 /  10  20  30  20
Brownwood   87  63  83  66 /  20  50  30  40
Sweetwater  91  62  84  63 /  10  20  40  40
Ozona       91  66  89  64 /   0  10  40  30
Brady       86  64  84  66 /  10  30  30  30

&&

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

$$

SHORT TERM...20
LONG TERM....50
AVIATION...AP