753
FXUS64 KEWX 151818
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
118 PM CDT Sun Sep 15 2024

...New AVIATION...

.UPDATE...
Issued at 1007 AM CDT Sun Sep 15 2024

Persistent cloud cover and light showers will keep temperatures down
into the mid and upper 80s today across portions of the Rio Grande
plains from Eagle Pass southward. Otherwise, the remainder of the
forecast appears on track at this time.

&&

.SHORT TERM...
(Today through Monday)
Issued at 200 AM CDT Sun Sep 15 2024

Mid and upper level energy associated with remnants of Tropical
Storm Ileana has been producing isolated showers and stratiform rain
across the Rio Grande and Winter Garden region, with more widespread
convection south of the CWA. Through the remainder of the overnight
and early morning hours this precipitation will be located near and
south of a Del Rio to Uvalde to Pleasanton line, then the forcing
weakens and shifts farther south of the area.

The second area and time of concern will be late this afternoon and
evening across the northeast half of the CWA. Models continue to
advertise the initiation of isolated to widely scattered showers and
storms between 3PM-7PM near and south of a weak surface front across
portions of the northeast Hill Country, central Texas and Austin
metro area, and southeast Texas. Propagation to the south and
southwest is indicated to take place into the evening hours, with
new isolated convection developing along outflow boundaries farther
south into the CWA. The activity could potentially make it as far
south as the southwest Hill Country, San Antonio area, and Coastal
Plains, but this is lower confidence. A few storms could produce
some stronger downburst given the high bases and DCAPE values
indicated on forecast soundings. Activity should gradually dissipate
late in the evening, although a couple of CAMs indicate isolated
activity after midnight. Temperatures will be warm again late this
afternoon, potentially near record highs for this date at Austin and
San Antonio.

The weak surface boundary looks to stall near the northeast CWA on
Monday, however ridging aloft builds slightly over the area which
may limit any chances for convective development. Most models are
not generating precipitation near and south of the boundary Monday,
with the exception of a few Canadian ensemble members, and a few CAMs
like the HRRR, FV3, and TT WRF, and even those indicate very
isolated coverage. Will keep the Monday forecast dry, with better
moisture and less ridging confined well south of the area. Continued
warm afternoon temperatures on Monday.

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 200 AM CDT Sun Sep 15 2024

Operational models and an overwhelming majority of ensembles show a
blocky pattern aloft over the CONUS and surrounding areas for mid to
late week with ridging over South Central Texas and Hill Country.
Meanwhile, southerly flow lower level flow persists. Well above
normal, summer-like temperatures continue. Subsidence underneath the
ridge will keep rain out of the forecast. However, cannot rule out a
shower or two from time to time, though mainly near the Coastal
Plains with the afternoon seabreeze.

The pattern aloft begins to break down going into next weekend. The
ridging flattens allowing a western states trough to shift to the
east toward the Plains states. Moisture levels increase and forcing
from the approaching trough could lead to low chances of showers and
thunderstorms on Saturday into Sunday.

&&

.AVIATION...
(18Z TAFS)
Issued at 102 PM CDT Sun Sep 15 2024

Mid and upper level clouds are gradually clearing across the TAF
sites as some afternoon cumulus clouds develop where clearing has
occurred. For late this afternoon and evening, the focus shifts to
our northeastern counties where a weak boundary is expected to help
in the development of convection. The hi-res models continue to favor
near and north of AUS for showers and storms today and we will
continue to mention a PROB30 for TSRA in the forecast at AUS. Farther
south, confidence is lower in convection reaching SAT and SSF and we
have removed the PROB30 groups from these terminals. Some light
shower activity may approach DRT this afternoon, but coverage is
expected to remain higher farther south of the terminal.

&&

.CLIMATE...
Issued at 200 AM CDT Sun Sep 15 2024

Record High Temperatures

                     Sep 15       Sep 16       Sep 17

Austin Bergstrom....99 (2005*)...99 (2019*)...99 (2005*)
Austin Camp Mabry...99 (1953)...101 (2019)....99 (2021)
Del Rio............102 (1912)...101 (1997)...103 (2021)
San Antonio.........98 (1988*)...99 (1954)....98 (1997)

* denotes previous years

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry             100  74  98  74 /  20  20   0   0
Austin Bergstrom Intl Airport  99  73  97  73 /  20  20   0   0
New Braunfels Muni Airport     99  73  99  74 /  10  10  10   0
Burnet Muni Airport            97  71  95  71 /  20  20   0   0
Del Rio Intl Airport           95  75  95  76 /  20   0  20   0
Georgetown Muni Airport        98  73  95  72 /  20  30   0   0
Hondo Muni Airport             94  73  95  73 /  20   0  10   0
San Marcos Muni Airport        97  73  97  73 /  10  20  10   0
La Grange - Fayette Regional   97  73  96  73 /  20  20   0   0
San Antonio Intl Airport       97  74  97  75 /  10  10  10   0
Stinson Muni Airport           96  74  98  75 /  10  10  10   0

&&

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

$$

Short-Term...Platt
Long-Term...Brady
Aviation...Platt