Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX

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FXUS64 KEWX 270531 AAA
AFDEWX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
1231 AM CDT Tue Jul 27 2021

.AVIATION...
/06Z TAFS/
VFR conditions are expected across the area sites for the most part.
The exception will be around 10Z to about 12Z for KSAT and KSSF as
low MVFR cigs develop. Otherwise, VFR conditions with light and
variable winds overnight and early Tuesday morning and out of the
southeast around 5 to 8 knots along the I-35 sites and 10 knots with
gusts up to 16 knots across KDRT.


&&

.PREV DISCUSSION... /ISSUED 641 PM CDT Mon Jul 26 2021/

AVIATION...
VFR conditions will generally prevail across South Central Texas
through the period. The exception will be a few hours around sunrise
at the I-35 terminals where brief drops to MVFR and/or IFR are
possible. A TEMPO has been added to cover this, but think these
reductions in ceilings will be short lived. Winds will generally be
south through the period as well, but some south-southwest winds are
possible overnight and during the morning hours. With moisture
increasing tomorrow as the high pressure moves away some of the
weather models do show isolated showers and storms for the late
morning into the evening. Coverage will be spotty, so no mention was
made in this TAF package, but AUS and DRT are the most likely
terminals to see any of these isolated showers if they do impact one
of the TAF sites.

PREV DISCUSSION...

SHORT TERM (Tonight through Tuesday Night)...
Latest GOES-16 WV imagery places a somewhat elongated Subtropical
Ridge to our northwest, centered over southeastern Colorado.
Meanwhile, a weak mid-level low is positioned over the western Gulf
of Mexico, spinning its way westward early this afternoon. This low
will have a small influence on our local weather, acting to trigger
the seabreeze tomorrow as enhanced moisture return is noted in hi-
res guidance for Tuesday afternoon. Temperatures will remain on the
toasty side, with 1PM obs already in the lower to middle 90s across
the region. Expect most spots to top out in the mid to upper 90s,
with triple digits not out of the realm of possibility at the major
climate sites AUS/SAT/ATT/DRT. Heat indices will remain below
advisory criteria, mainly in the 100-107 range. Expect mainly clear
skies and light east-southeasterly winds.

A mild and muggy night tonight as temperatures remain near seasonal
norms in the lower to middle 70s. Expect a "slightly" cooler day on
Tuesday, as a weak mid-level impulse rounds the eastern periphery of
the Subtropical Ridge to our northwest, resulting in some isolated
showers or storms developing by midday, especially across the
Coastal Plains, Hill Country, and portions of the Southern Edwards
Plateau. 12Z Hi-Res models are more into the possibility of isolated
convection popping up by 18Z Tuesday and moving in from northeast to
southwest. Will go with slight chance PoPs and have collaborated
with FWD office to add low end PoPs into the forecast. Any showers
or storms should quickly fall apart after 00Z follow by a quiet
Tuesday night.

LONG TERM (Wednesday through Monday)...
A couple of mid level impulses will move west over Southern Texas
and northeastern Mexico while passing underneath the Subtropical
Ridge centered over the Central Plains on Wednesday. Forcing by the
impulses and heating of a seasonally moist airmass will generate
isolated to widely scattered mainly afternoon showers and
thunderstorms.

The Subtropical Ridge becomes the dominant feature for the remainder
of this week into next week while centered over the Central/Southern
Plains. With increased subsidence and decreased moisture, most areas
will be rain-free. The exception being areas near the Coastal Plains
where the seabreeze may generate isolated showers and thunderstorms
mainly Friday afternoon. There is a potential for a couple of mid
level impulses this weekend and/or next week, however, models show a
lack of consistency and consensus. Later forecasts may have to
include slight chances of showers and thunderstorms for parts of
those days.

Near to slightly above normal temperatures are expected. Decreasing
soil moisture, drying vegetation, and mixing of drier air aloft make
heat index values only mildly elevated.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              98  77  97  75  97 /  20  10  30  -   10
Austin Bergstrom Intl Airport  98  75  94  73  96 /  20  10  20  -   10
New Braunfels Muni Airport     97  74  95  73  96 /  10  -   20  -   10
Burnet Muni Airport            97  75  94  74  95 /  20  10  30  -   10
Del Rio Intl Airport          102  77  99  76  99 /  10  10  20  20  10
Georgetown Muni Airport        99  76  95  74  97 /  20  10  30  -   10
Hondo Muni Airport             97  74  95  73  96 /  -   -   20  -   10
San Marcos Muni Airport        98  74  96  73  97 /  20  -   20  -   10
La Grange - Fayette Regional   97  76  95  75  96 /  20  -   20  -   10
San Antonio Intl Airport       97  75  93  74  94 /  -   10  20  -   10
Stinson Muni Airport           98  76  96  75  96 /  -   -   20  -   10

&&

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

$$

Short-Term/Aviation...17
Long-Term...05


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