447
FXUS64 KEWX 220600 AAA
AFDEWX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
100 AM CDT Sun Sep 22 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Sunday night)
Issued at 108 PM CDT Sat Sep 21 2024

Daytime mixing will continue to scatter out low clouds and produce
partly cloudy, and then mostly clear, skies late this afternoon into
early evening. The general pattern of low-level clouds returning by
late evening and persisting overnight into the next morning will
continue, but lower boundary layer humidity should result in less
fog along and east of I-35/I-37 Sunday morning.

The approach of a longwave trough and near-surface cold front will
bring sufficient lift for showers and a few thunderstorms across the
northern Rio Grande Plains, Edwards Plateau, and western Hill
Country Sunday evening into the overnight hours. Rainfall will be
spotty and average 1/10 inch or less. Daytime temperatures will be 2-
4F cooler across the entire area on Sunday because of additional
cloudcover.

&&

.LONG TERM...
(Monday through Saturday)
Issued at 108 PM CDT Sat Sep 21 2024

A much-needed pattern change appears to be on the way for the
last full week of September. A mid-level trough will gradually erode
the 500mb high that`s been keeping things hot and dry for the last
couple of weeks in South Central Texas. On Monday, a cold front will
start sliding southward into the Hill Country and Southern Edwards
Plateau. Model trends continue to bring this front to a halt over the
Hill Country late Monday and it is unlikely to make much progress
until late Tuesday per the latest Canadian/ECMWF runs. The GFS is not
as aggressive with forcing the boundary south, but the trend is your
friend, and this time of year usually calls for frontal boundaries
sliding further south the global model guidance usually suggests. In
any matter, cooler temperatures, ample cloud cover, and an
overrunning regime should result in scattered showers and the
occasional isolated thunderstorm Monday afternoon, Tuesday
afternoon, and again Wednesday afternoon and evening.

By Thursday, the mid-level trough should start to finally shift
eastward into the Ohio Valley, resulting in a drying trend for the
region. Dewpoints will be much more manageable, as slightly cooler,
more so drier air, will work its way south with the frontal boundary.
Expect more seasonable high and low temperatures in the 80s
Wednesday, with mid to upper 80s and perhaps some lower 90s
Thursday-Saturday.

&&

.AVIATION...
(06Z TAFS)
Issued at 1251 AM CDT Sun Sep 22 2024

Low clouds continue to expand along the I-35 corridor early this
morning and we have started either prevailing or TEMPO groups for
MVFR clouds a little ahead of schedule. Low clouds will eventually
expand westward to DRT, with MVFR remaining in the forecast here as
well. Low clouds will lift and mix back to VFR around 17Z, with VFR
expected through this evening. Low cloud development is likely again
early Monday morning and will mention SCT low clouds toward the end
of our 30 hour sites (SAT and AUS). We could also see some convection
develop near or just north of DRT late tonight or early Monday. For
now, confidence is on the low side and will not mention in the TAF
just yet.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              96  74  93  73 /   0  10  10  10
Austin Bergstrom Intl Airport  95  73  93  73 /   0   0  10  10
New Braunfels Muni Airport     96  73  95  73 /   0   0  10  10
Burnet Muni Airport            92  71  87  69 /   0  20  20  10
Del Rio Intl Airport           95  76  91  75 /   0  30  40  10
Georgetown Muni Airport        94  73  90  71 /   0  10  10  10
Hondo Muni Airport             94  72  93  73 /   0  10  10  10
San Marcos Muni Airport        94  71  93  71 /   0   0  10  10
La Grange - Fayette Regional   94  72  93  72 /   0   0  10  10
San Antonio Intl Airport       94  75  93  75 /   0  10  10  10
Stinson Muni Airport           95  74  96  75 /   0   0  10  10

&&

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

$$

Short-Term...Platt
Long-Term...17
Aviation...Platt