058
FXUS64 KEWX 011120
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
620 AM CDT Wed May 1 2024

...New AVIATION...

.SHORT TERM...
(Today through Thursday)
Issued at 310 AM CDT Wed May 1 2024

Key Points

* Isolated to scattered strong to severe storms this afternoon
  through tonight
* Large (possibly very large greater than >2 inch) hail and damaging
  winds the main threats
* A tornado or two is possible
* Locally heavy rainfall and flooding possible

A warm and humid airmass remains over South Central Texas early this
morning. Several features will provide forcing for showers and
thunderstorms of this airmass. These are an approaching mid level
shortwave, the dryline in western Texas, the Serranias del Burro of
Mexico, and heating. There may be a few showers or patchy drizzle
this morning. Then, showers and thunderstorms will develop over
parts of our area, as well as along the dryline and over the
Serranias del Burro this afternoon. A strengthening moist southerly
low level jet and the passage of the shortwave will maintain the
showers and thunderstorms this evening through early Thursday with
them organizing into clusters while some supercells remain discrete.

Forecast soundings show MUCAPE of 3,000 to 4,000 j/kg, mid level
lapse rates of near 8 C/km, and 0-6 km shear around 30 kts. This
indicates a potential for severe storms. Large, possibly very large
hail and damaging winds are the main threats, however a tornado or
two is possible. SPC has our area in a marginal to slight (1 and 2 out
of 5) risk for severe storms. The greatest risks are for Val Verde
County, Edwards Plateau, Hill Country, and Central Texas.

Above seasonal normal PWS as high as 2 inches indicate a potential
for heavy rains, especially where storms train or possibly stall.
These heavy rains would mostly cause urban and small stream type
flooding with a few cases of flash flooding possible. WPC has our
area in a marginal to moderate (1 to 3 out of 4) risk of excessive
rainfall. The greatest risks are from Central Texas to the US 77
corridor.

The exit of the shortwave will take the activity east of our area
Thursday morning leaving a somewhat stabilized airmass. As a result,
expect mainly isolated showers and thunderstorms Thursday afternoon
due to heating, the dryline into Val Verde County, and any leftover
surface boundaries. Can`t rule out a strong to severe storm or two
and locally heavy downpours. Above normal temperatures continue
today through Thursday.

&&

.LONG TERM...
(Thursday night through Tuesday)
Issued at 310 AM CDT Wed May 1 2024

Slight to low end chances for showers and thunderstorms are forecast
for the Hill Country and areas along and east of Highway 183 on
Thursday night. The shower and thunderstorm activity shifts to the
east as the night progresses and a mid level short wave pushes into
east Texas. Expect patchy fog to develop overnight and to continue
into Friday morning mainly for locations along and east of
Interstate 35 corridor. Overnight lows are forecast to range from
the upper 60s across the Hill Country to mid 70s across the Rio
Grande and Coastal Plains.

The patchy fog and even some hazy skies are forecast for Friday
morning with a slight chance for showers and storms mainly to the
east of Highway 77. Partly cloudy to cloudy skies are expected
across South Central Texas on Friday afternoon with highs in the mid
80s across the eastern half of the local area to low and mid 90s
across the southern Edwards Plateau and Rio Grande. An active dry-
line over west Texas is likely to help with the generation of
showers and thunderstorms ahead of the boundary. Those showers and
storms are likely to push across the Serranias del Burro Mountains
and into the Rio Grande late Friday afternoon into the evening. Can`t
rule out a strong storm to move into the Del Rio or vicinity areas
and then follows a southeastern track based on mid to upper level
flow. This activity could be over by midnight or shortly after.

Saturday begins cloudy with some breaks in the clouds by the
afternoon. Highs in the 80s across the Hill Country, I-35 corridor
and Coastal Plains and low 90s along the Rio Grande. With some
instability in place and the passage of an upper level disturbance,
expect new shower and storm development across the Rio Grande and
southern Edwards Plateau on Saturday afternoon and part of the
evening.

By Sunday, a stationary front is forecast to be located across
Central Texas while the dry-line sits over west Texas. In addition,
a pulse of energy in the mid to upper level flow from the southwest
is likely moving over Central Texas. The combination of these
features bring a low end chance for showers and storms across the
Hill Country, southern Edwards Plateau and Rio Grande. Nearby San
Antonio areas and locations to the south and east are expected to
stay dry. Highs in the 80s most areas with low 90s along the Rio
Grande.

For the start of the work week, an upper level short wave is
forecast to push across the Southern Plains and the active dry-line
pushes across Val Verde County. Medium range models keep showers and
storms to the north of the local area, however, this could change in
future weather packages as we get closer to the weekend.
Temperatures are increasing as we move into Tuesday and Wednesday
with highs in the mid to upper 90s and up to 100 and 105 range along
the Rio Grande.

&&

.AVIATION...
(12Z TAFS)
Issued at 620 AM CDT Wed May 1 2024

A mix of IFR/MVFR CIGs will lift to VFR this afternoon, then lower
back to a mix of IFR/MVFR later this evening through tonight.
SHRA/TSRA will develop this afternoon, then continue through this
evening out west and through much of tonight in the east. Have
maintained PROB30s. Later forecasts may have to update to go
prevailing. The SHRA/TSRA may disrupt the lower CIGs tonight for a
time. Light to moderate S to SE winds prevail with the possibility of
strong wind gusts with the TSRA.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              85  70  84  72 /  60  70  40  20
Austin Bergstrom Intl Airport  84  69  84  71 /  60  70  40  20
New Braunfels Muni Airport     87  71  86  72 /  60  60  20  20
Burnet Muni Airport            82  69  83  70 /  50  70  40  20
Del Rio Intl Airport           89  74  96  75 /  20  30  10   0
Georgetown Muni Airport        84  69  83  70 /  50  80  50  30
Hondo Muni Airport             87  69  85  70 /  50  60  20  10
San Marcos Muni Airport        86  69  85  70 /  60  60  30  20
La Grange - Fayette Regional   86  72  84  72 /  50  60  40  20
San Antonio Intl Airport       85  70  85  72 /  50  60  20  10
Stinson Muni Airport           87  72  86  72 /  60  50  20  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Short-Term...04
Long-Term...17
Aviation...04