778
FXUS64 KEWX 041730
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1230 PM CDT Sat May 4 2024

...New AVIATION...

.SHORT TERM...
(Today through Sunday)
Issued at 440 AM CDT Sat May 4 2024

East to southeasterly winds at the surface are in place across south
central Texas early this morning according to the latest observations.
In addition, radar VWP plots show a fairly deep fetch of southerly
winds from just above the surface to around 10k MSL. Radar data also
shows some light showers across the coastal plains and out west along
the Rio Grande. Elsewhere, surface obs show a stout cold front
across the Texas Panhandle.

Precipitation chances this morning will be low and in the form of
either light drizzle or light rain showers. Clouds will remain thick
with plenty of moisture in the lower levels of the atmosphere. We
also expect to see patchy fog continue across most areas this
morning. For the afternoon hours, rain chances across south central
Texas remain fairly low, with models showing convection most favored
across west Texas as the above mentioned front drops southward. We
will keep a low chance for showers and thunderstorms in the forecast
for the Rio Grande plains, southern Edwards Plateau and Hill Country
as some of the hi-res members show some development during the peak
heating hours. Low clouds have been slow to dissipate over the last
several days and this may put a damper on afternoon heating and
destabilization of the lower levels. Some breaks in the clouds should
occur farther west along the Rio Grande and into the southern
Edwards Plateau region, and we have shown some slightly higher rain
chances across these mentioned areas for this afternoon. Daytime
highs will be tricky again with the expected cloud cover. We have
gone with lower 90s along the Rio Grande with 80s elsewhere.

The weather pattern should turn active as the evening progresses for
areas generally west of the I-35 corridor. First up will be
convection that develops over the higher terrain of Mexico that may
move into the Rio Grande plains during the late afternoon or evening
hours. In addition, convection moving out of west Texas should
congeal into a cluster with the leading edge moving into the Hill
country and southern Edwards Plateau during the late evening hours
to around Midnight. During the early morning hours on Sunday, models
suggest this cluster of storms will move east or southeast into the
I-35 corridor. There will be a concern for severe storms this
evening and overnight with large to possibly very large hail and
damaging winds being the main concerns. In addition, a tornado can`t
be ruled out. As of now, it appears the lower Trans Pecos region
into the southern Edwards Plateau, including northern Val Verde
county will be under the higher chances for severe weather, with SPC
showing an Enhanced Risk (level 3 of 5) in the latest Day 1 outlook.
It would not take much expansion for this higher risk area to move
into portions of the western Hill Country. For the early morning
hours on Sunday, the severe threat will shift east and southeast
into the Hill Country and I-35 corridor and areas generally along
and north of an Eagle Pass to San Antonio to Taylor line will be in
the Slight Risk (level 2 of 5) category for severe storms. For areas
mainly east of the I-35 corridor, there will be a Marginal Risk for
severe storms. The models show good potential for some locally heavy
rainfall as well, especially across the southern Edwards Plateau
into portions of the Hill Country where some of the hi-res models
show more rounds of precipitation persisting well into Sunday
morning along the southward dropping leading edge of the cold front
or convective outflow boundary. Precipitation chances for Sunday
afternoon will largely depend on how convection unfolds during the
morning hours. For now, we will show a decent chance of precipitation
during the afternoon hours across most locations. Given the expected
precipitation and cloud cover, highs on Sunday will trend downward,
with upper 70s to upper 80s in the forecast.

&&

.LONG TERM...
(Sunday night through Friday)
Issued at 222 AM CDT Sat May 4 2024

Rain chances trend downward Sunday night into early Monday as a more
stable zonal pattern aloft builds into TX. PWat values will remain
elevated for a few showers, perhaps an isolated storm to form during
the day Monday. Models show a thermal ridge encroaching into our
western counties by midweek, but have trended slightly cooler and
less dry over the past several runs. Even so, the mixing of dry air
into western counties could bring some triple digit heat while
bringing up the heat index to near triple digits over central
counties. Wednesday and Thursday look to be the warmest days of the
week, but Friday morning cold front has trended earlier to a late
Thursday arrival, which could lead toward further moderation of the
mat temp on that day. No significant rain chances are depicted along
the front, but some overrunning rain chances are suggested for
Friday. If this occurs, the max temps for Friday will be trending
down as well.

&&

.AVIATION...
(18Z TAFS)
Issued at 1228 PM CDT Sat May 4 2024

MVFR to local IFR cloud cover continues to linger over much of South
Central Texas. Expect ceilings to lift to VFR by 20-21Z everywhere
except over the Hill Country where MVFR conditions look to remain.
Low ceilings will redevelop around 03-04Z tonight, dropping as low
as IFR to LIFR early Sunday morning. Thunderstorms are expected to
develop this evening, moving across much of the area through Sunday
morning. Believe any activity early this evening will stay west of
DRT, and have introduced PROB30 groups to sites for the best timing
as a complex or line or storms moves across the area later in the
night. Showers and thunderstorms may linger behind this initial line
of storms through the day Sunday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              70  82  71  86 /  80  60  20  10
Austin Bergstrom Intl Airport  68  81  70  86 /  80  60  20  10
New Braunfels Muni Airport     71  84  71  88 /  70  60  20  10
Burnet Muni Airport            67  79  70  84 /  90  60  20  10
Del Rio Intl Airport           72  87  74  95 /  60  50  10  10
Georgetown Muni Airport        67  80  69  84 /  80  60  20  10
Hondo Muni Airport             69  83  70  87 /  80  50  10  10
San Marcos Muni Airport        69  82  70  86 /  70  60  20  10
La Grange - Fayette Regional   72  82  72  86 /  60  60  20   0
San Antonio Intl Airport       71  82  72  86 /  70  50  20  10
Stinson Muni Airport           72  84  73  88 /  60  50  20  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 4 PM CDT this afternoon through Sunday afternoon
for Burnet-Lee-Llano-Williamson.

&&

$$

Short-Term...Platt
Long-Term...18
Aviation...27