-- Discussion containing changed information from previous version are highlighted. --
757
FXUS64 KSJT 221816
AFDSJT

Area Forecast Discussion
National Weather Service San Angelo TX
116 PM CDT Wed May 22 2024

...New LONG TERM...

.SHORT TERM...
(Today and tonight)
Issued at 416 AM CDT Wed May 22 2024

...Severe storms expected this afternoon into tonight...

Currently, we have light southeasterly flow to the south of a
cold front that is moving south through the southern plains. This
cold front is expected to move south into our area today, with
most guidance showing the front near or just south of a San Angelo
to San Saba line by mid to late afternoon. Temperatures by mid
afternoon south of the front will climb well into the 90s, while
north of the front, low to mid 80s are likely. Dewpoint values are
expected to remain in the mid 60s to low, and possibly mid 70s,
with increasing moisture the farther east you go. This combination
of warm temps and high dewpoints will yield CAPE values along and
south of the front from 3000 to as high as 4400 J/kg. This
instability, along with ample mid level instability, and deep
layer shear values of 40+ knots will result in any thunderstorms
developing quickly strengthening to severe levels. Not only will
these storms be severe, but hail of 2 inches or larger is likely,
especially with the initial storms that are expected to be
discrete supercells. Along with the very large hail, a few
tornadoes are also possible, particularly any storms that move
along the frontal boundary or any outflow boundaries from
neighboring storms. Individual storm motions are expected to be to
the east/southeast, but some right-moving storms will likely
develop a more southerly direction. As the event evolves, these
discrete storms should grow upscale into a southeastward moving
MCS during the evening hours. As this occurs, there will be a
growing risk for severe wind gusts in addition to large hail, and
a few tornadoes. Expect most of the thunderstorm activity to be
south and east of our area by Midnight or so, although some of the
CAMs do develop additional scattered showers and storms after
midnight, mainly south of I-20. These should be much less intense,
but could offer some marginally severe hail or wind gusts.

Other than the storms, temperatures will be hot south of the
front, and combined with dewpoints in the 60s to lower 70s, there
is a risk for heat-related illnesses for anyone working or
exercising outside. Overnight lows will be in the mid 60s to lower
70s.

&&

.LONG TERM...
-- Changed Discussion --
(Thursday night through next Wednesday)
Issued at 116 PM CDT Wed May 22 2024

...Potential Heat Impacts for the Holiday Weekend...

A weak cold front is expected to move south into our area on Friday.
It won`t have a big impact on temperatures, especially in the
southern half of our area, where west winds will bring in hot
downsloping air for much of the day. The front will help keep
temperatures in the Big Country and Heartland in the low to mid 90s,
while the rest of the area pushes into the upper 90s and lower 100s.
Return flow will be quick to return, with winds back from the south
by Saturday morning. On Saturday, the dry line is expected to move
east through much of our area, bringing strong southwest/west winds.
This will help increase temperatures in the southwestern half of our
forecast area into the 100 to 105 degree range. Areas to the east of
the dry line could experience heat impacts as well, due to the high
moisture leading to heat indices above 100. Temperatures on Sunday
will be very hot as well, but the Wet Bulb Globe Temperature
forecast is pointing to a lower risk for heat related illnesses on
Sunday compared to Saturday for those outside this weekend. The GFS
is showing a cold front early Monday and the European has it moving
through late Tuesday, leading to uncertainty in both the
temperatures and precipitation chances to start out next week.

As for rain chances in the long term, there are a few days where
certain areas could have a slight chance of rainfall. A little upper
level disturbance could move through the flow aloft both Friday and
Saturday afternoon/evening. Right now, rain chances are better to
our east, leaving us dry, but it will depend on the location of the
dry line and the disturbance. If the dry line stays a little further
west then we could see some rain in our eastern counties (and
potentially some strong to severe storms). The best rain chances in
the long term will be Tuesday into Wednesday as an upper level
disturbance moves through. The timing of the front will help to
determine exactly how widespread the rain will be. If the lift from
the front and the lift from the disturbance can combine they could
produce higher storm coverage.
-- End Changed Discussion --

&&

.AVIATION...
(18Z TAFS)
Issued at 1203 PM CDT Wed May 22 2024

Storms expected to develop along southward-moving cold front
this afternoon and evening could produce sudden wind shifts and
large hail. MVFR to IFR ceilings late tonight and tomorrow morning
will be very ragged with several breaks likely. Additional showers
and or storms are possible tomorrow morning, but these were left
out of the 12 to 18Z time period due to low confidence.

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene     68  90  69  92 /  20  20   0   0
San Angelo  70  98  67 100 /  20  10   0   0
Junction    72  98  72 101 /  30  20   0  10
Brownwood   69  88  69  93 /  40  30   0   0
Sweetwater  68  95  67  92 /  10  10   0   0
Ozona       70  98  67  99 /  20  10   0   0
Brady       70  90  71  95 /  40  30   0  10

&&

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

$$

SHORT TERM...20
LONG TERM....AP
AVIATION...SK