407
FXUS64 KEWX 050015
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
715 PM CDT Sat May 4 2024

...New MESOSCALE UPDATE...

.MESOSCALE UPDATE FOR SEVERE THUNDERSTORM WATCH 185
... Issued at 715 PM CDT Sat May 4 2024

We are monitoring two areas for potential severe thunderstorm
development through the overnight hours. The first is along the Rio
Grande as two strong to severe supercells are currently ongoing to
the west of the International Border. These storms will continue to
push east through the evening and may make it across the border
before weakening, presenting a large to very large hail and damaging
wind gust threat. The other area we are monitoring is west Texas into
the Big Country where several severe thunderstorms are currently
ongoing. One of these storms currently across Terrell County has had
a history of producing tornadoes, and will be moving into Val Verde
County in the coming hours where a Tornado Watch remains in effect.
Otherwise, these storms are expected to grow upscale through the
remainder of the evening with an MCS expected to move through the
Severe Thunderstorm Watch area overnight with a wind, hail, and
heavy rain/flooding threat. A local extension of the Watch may be
needed for eastern counties later on depending on storm trends.

-Gale

&&

.SHORT TERM...
(Tonight through Sunday night)
Issued at 244 PM CDT Sat May 4 2024

A dryline is located in west Texas with a surface front draped
across the northern portion of the state just south of the
panhandle. South Central Texas continues to stay in the warm, humid
airmass ahead of these features with thick cloud cover and humid
conditions continuing today. A few isolated showers or thunderstorms
will be possible this afternoon around peak heating, although the
higher confidence for precipitation in the area arrives this evening
through Sunday morning.

Thunderstorms will likely develop west of the area late this
afternoon along the front and the dryline extending over the higher
terrain in Mexico. Much like previous nights, the question is
whether the storms west of the Rio Grande will make it across the
river into our far western reaches. Of higher confidence are the
storms in west Texas becoming a complex which will will shift
eastward overnight into Sunday aided by a passing shortwave trough.
This complex of storms may become a line with the leading edge
moving across the Hill Country or southern Edwards Plateau a little
before midnight. This complex will likely move through portions of
the I-35 corridor and Coastal Plains into Sunday morning. There is
the potential for storms to be severe tonight, especially in the far
west where initial development is anticipated. Large to very large
hail, damaging wind gusts, or an isolated tornado will all be
possible. As storms progress into a line, damaging winds may become
the primary hazard later in the night. SPC has continued the Level 3
of 5 Risk across far northwestern Val Verde County, with a Level 2
of 5 risk across portions of the southern Edwards Plateau, Rio
Grande Plains, Hill Country, and I-35 corridor. In addition to this
threat, heavy rainfall leading to isolated flash flooding is also a
concern. Much of where the heaviest rain is expected depends on the
track of the line of storms this evening, but the best potential
looks to be in the far northeastern portion of the area. A Flood
Watch has been issued for Llano, Burnet, Williamson, and Lee
Counties through Sunday afternoon based on this potential and the
potential for some additional rain on Sunday.

Precipitation chances continue through Sunday afternoon and early
Sunday evening, although there is much more uncertainty in exact
details after any morning storms. It is likely some kind of outflow
boundary will remain in the area and with destabilization in the
afternoon, additional thunderstorms may develop along this feature.
Storms would once again have the potential to become severe with
large hail the initial threat. Upscale growth may occur as some
models do depict a secondary line of storms moving across the area
in the afternoon hours. Rain and thunderstorm chances finally
decrease Sunday night as the upper level shortwave moves into the
southeastern US.

&&

.LONG TERM...
(Monday through Saturday)
Issued at 244 PM CDT Sat May 4 2024

The day on Monday starts relatively dry with cloudy skies and
temperatures in the upper 60s and low 70s for the morning commute.
As the day progresses, the clouds are forecast to break for partly
cloudy skies with highs reaching the mid to upper 80s most locations
and low 90s along the Rio Grande. The active dry-line is likely
lingering between west Texas and Val Verde County during the
afternoon. Isolated showers and thunderstorms could develop across
the Hill Country in the afternoon, otherwise, dry and warm for the
most part.

A dry and warm pattern is in store from Tuesday into Thursday with
high temperatures getting warmer each day. Thursday is forecast to
be the warmest day of this week with temperatures in the upper 80s
to mid 90s across the Hill Country, I-35 corridor and Coastal
Plains to the 100-104 range along the Rio Grande.

A cold front is forecast to push across the local area late Thursday
night into Friday and brings a slight chance for showers and storms
mainly on Friday. Friday`s highs will be much cooler with
temperatures in the upper 70s to mid 80s across the northern part of
South Central Texas and low 90s along the Rio Grande.

&&

.AVIATION...
(00Z TAFS)
Issued at 630 PM CDT Sat May 4 2024

Widespread cigs are in place across south-central Texas to begin the
period, though most locations are at/above VFR. Cigs will lower later
this evening and overnight to IFR/low-end MVFR, corresponding with
an increased chance for showers and storms as a convective complex
moves in from west Texas. Areas generally along and north of I-10
have the best chances of seeing this activity through the pre-dawn
hours Sunday. After sunrise, scattered thunderstorm activity may
redevelop behind the line with showers and storms continuing into the
afternoon hours, though there is less confidence in this second
round of activity for the time being. Regardless, conditions will
improve late afternoon through the end of the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              69  82  71  86 /  80  60  20  10
Austin Bergstrom Intl Airport  68  82  71  86 /  80  60  20  10
New Braunfels Muni Airport     70  83  71  88 /  70  60  20  10
Burnet Muni Airport            67  79  69  84 /  90  60  20  10
Del Rio Intl Airport           72  85  72  95 /  60  50  10  10
Georgetown Muni Airport        67  80  70  84 /  80  60  20  10
Hondo Muni Airport             68  82  70  87 /  80  50  10  10
San Marcos Muni Airport        68  82  71  86 /  70  60  20  10
La Grange - Fayette Regional   71  82  72  86 /  60  60  20   0
San Antonio Intl Airport       69  82  72  86 /  70  50  20  10
Stinson Muni Airport           71  83  72  88 /  60  50  20  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Sunday afternoon for Burnet-Lee-Llano-
Williamson.

&&

$$

Short-Term...27
Long-Term...17
Aviation...Gale