San Antonio, Texas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

720
FXUS64 KEWX 031414
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
814 AM CST Tue Dec 3 2024

...New UPDATE...

.UPDATE...
Issued at 811 AM CST Tue Dec 3 2024

Based on radar trends and the latest hi-res guidance, we have pushed
rain chances a little farther north into the I-35 corridor, Hill
Country and coastal plains. Rainfall amounts will still remain very
light, likely only a few hundredths of an inch, due to the dry sub-
cloud layer. Some minor changes were also made to the hourly
temperatures and dew points to account for the latest observational
trends.

&&

.SHORT TERM...
(Today through Wednesday)
Issued at 111 AM CST Tue Dec 3 2024

Surface high pressure in the plains will shift southeast through
tonight while a trough off the coast of northern Mexico shifts north
towards South Texas. This will reinforce easterly to southeasterly
surface flow increasing moisture across the area today. Light
returns are seen on radar over the Rio Grande and coastal plains
this morning, though little precipitation is expected as the sub-
cloud layer is predominantly dry through the day. That said, cannot
rule out some very light rain or sprinkles. Mostly cloudy to
overcast skies will persist this afternoon with highs from the upper
50s to upper 60s. Isentropic ascent strengthens later tonight into
Wednesday bringing the best potential for light precipitation to the
area. Some weak elevated instability may exist in the east Wednesday
as the surface low moves across the southeastern portion of the CWA
which could lead to some rumbles of thunder, but light showers will
be the predominant feature. Total forecast rain amounts are
generally around a few hundredths of an inch up to 0.15 inches.
Overcast skies will stick around for much of the day Wednesday,
clearing slightly in the west during the mid to late afternoon.
Highs range from the low 60s to low 70s.

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 111 AM CST Tue Dec 3 2024

Slightly more stable mid level air arrives into Central TX Wednesday
night as the deeper moisture layer from the coastal disturbance
shifts east. A few residual showers could still form over the Hwy 77
Corridor where there may still be some low level convergence and
moisture. A reinforcing cold front arrives at daybreak and begins to
refocus another round of overrunning moisture as an upper trough
approaches from the west. Daytime Thursday should be mostly dry with
a few light sprinkles possible from elevated lift over S/W counties.

The overrunning pattern tightens up quickly Thursday evening, and the
upper low being then located over Nrn Mexico should present a robust
lifting layer from above the inversion through the mid levels. Deep
layer convection and thunder becomes possible and could continue
through Saturday night as the upper low lifts NE into North TX
through Sunday.

The 00z GFS is extra generous on rain chances and has some agreement
from the CMC runs, showing a potential heavy rain threat of 2-3
inches mainly west of I-35 from 00Z Saturday to 00Z Sunday. The ECM
is noticeably drier and slower with the higher rain chances, but did
show some agreement with the newer GFS solutions in earlier runs.
With the better rain chances scattered over multiple days between the
various runs, the NBM is more dampened, and given our drought is
still the model of choice. This means we should maybe see some
pockets of 1+ inch rains, but with most areas getting totals below
half an inch through Sunday. But given the sporadic outputs of higher
rainfall potential, it`s at least worth a mention in the AFD. While
the rainfall timing and amounts will be in low confidence, there is
higher confidence that we`ll see chilly weather and a few days
without sunshine prior to Sunday. Sunday and Monday shown to be be
milder weather days with still some convection over east counties and
potentially over a broader part of the forecast area should the 00Z
ECM solution win out.

&&

.AVIATION...
(12Z TAFS)
Issued at 520 AM CST Tue Dec 3 2024

VFR conditions are expected through this evening. Mostly cloudy or
overcast skies are forecast today with patchy light rain possible
this morning. Have kept any mention of precipitation out of the TAFs
given its spotty nature until Wednesday morning when greater chances
for showers exist. Ceilings will drop to MVFR at sites between 02-
05Z with IFR conditions possible at SAT/SSF near sunrise.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              65  51  62  53 /  20  30  50  20
Austin Bergstrom Intl Airport  66  51  64  53 /  20  30  50  20
New Braunfels Muni Airport     64  52  67  56 /  20  30  50  20
Burnet Muni Airport            63  49  60  50 /  10  20  40  10
Del Rio Intl Airport           63  53  69  53 /  10  10   0   0
Georgetown Muni Airport        65  50  61  51 /  10  20  50  20
Hondo Muni Airport             62  52  67  56 /  20  30  20  10
San Marcos Muni Airport        65  51  67  53 /  20  30  50  20
La Grange - Fayette Regional   66  52  69  54 /  20  30  60  40
San Antonio Intl Airport       62  53  67  57 /  20  30  40  10
Stinson Muni Airport           64  55  69  59 /  20  40  40  10

&&

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

$$

Short-Term...Platt
Long-Term...MMM
Aviation...Platt