355
FXUS64 KEWX 250733
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
233 AM CDT Wed Sep 25 2024

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(Today through Thursday)
Issued at 205 AM CDT Wed Sep 25 2024

A few pop-up showers are forming across Central TX overnight, but
with well below 10 percent coverage and no remaining surface focus. A
more concentrated focus of convection over West Central/North
Central TX is located along the next front to arrive, and a distinct
frontal boundary can be seen on radar early this morning. Tracking
the movement on radar, this front is moving about 15 mph due
southward and should still be arriving into our northern CWA just
after sunrise. However, the boundary will probably be less traceable
once arriving into South Central TX as winds above the boundary
layer out of the north ahead of the front will mix down and reduce
surface convergence. There will still be some speed convergence in
the mixed layer late in the morning, so isolated convection will
still be possible, but will be quickly shifting southeast of the
escarpment by midday and out of the forecast area by 00Z.

The breezy north midday winds will be sufficient enough to trend
high temperatures down but mainly just over the northern counties
today. More noticeable changes will be expected in the evening with
a pleasant north breeze and the dew points falling into the 50s to
low 60s. As winds decouple some by Thursday morning, lows should
drop to the 60s or lower area-wide, with mainly the Hill Country
seeing the lows in the mid/upper 50s. The persistence of north winds
at the surface and aloft should be good for a drop of high
temperatures back to seasonal values for late September, or mainly
in the mid 80s to low 90s.

&&

.LONG TERM...
(Thursday night through Tuesday)
Issued at 205 AM CDT Wed Sep 25 2024

A mid and upper level low combined with the remnants of `Helene` will
remain anchored over the southeastern U.S. into the middle
Mississippi River valley through the end of the week. On the backside
of this low, north to northwest flow remains intact on Friday with
the medium range models showing a weak upper disturbance dropping
southward into the region into the upcoming weekend. While these
disturbances would normally be monitored for rain chances, with a dry
air mass in place, we do not expect any chance for rain through the
upcoming weekend. As these disturbances roll through, a reinforcing
shot of northerly winds in the lower levels is anticipated Friday,
with perhaps another weak surge late Saturday into early Sunday. With
dry air in the low-levels and clear skies, overnight lows will dip
into the mid to upper 50s over the Hill Country, with lower to mid
60s elsewhere. Daytime highs will range from the mid 80s to mid 90s,
with the warmest temperatures out west along the Rio Grande.

For the early portion of next week, the mid and upper level ridge
axis begins to build eastward into the southern U.S. plains.
Temperatures may warm slightly on Monday, with models showing a surge
of cooler air possibly moving into the region on Tuesday.

&&

.AVIATION...
(06Z TAFS)
Issued at 1241 AM CDT Wed Sep 25 2024

Based on the downward PoP trends, there is probably a 5 percent
chance of overnight convection near a TAF VCNTY and no more than a 15
percent chance during the daytime. While the overnight boundary layer
shows a south wind and some decent surface dew points in the upper
60s to low 70s, model initialized winds at 850 mb are north to
northwest, meaning dry air advection is already occurring over the
area. There is still some mid level moisture pooled over North and
Central TX, but the MOS guidance trends suggest isolated impacts if
any. Thus with no convection mentioned, the attention shifts to
prefrontal clouds and/or possible fog. While this is not out of the
question for the I-35 sites, the MOS signals suggest only some lower
Coastal Prairies areas to see this pre-frontal moisture pooling. So
with VFR skies expected through the period, the only focus for the
TAFs going forward is the gusty winds. North winds will begin to
escalate gradually with mixing, so there isn`t much need to track a
FROPA. All sites should shift to northerlies within a couple hours of
each other in the late morning. Some afternoon gusts to 25 KTs are
possible.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              92  66  90  63 /  10   0   0   0
Austin Bergstrom Intl Airport  93  66  88  60 /  20   0   0   0
New Braunfels Muni Airport     97  66  92  61 /  20   0   0   0
Burnet Muni Airport            86  62  86  59 /  10   0   0   0
Del Rio Intl Airport           98  67  93  66 /  10   0   0   0
Georgetown Muni Airport        87  63  86  60 /  10   0   0   0
Hondo Muni Airport             96  65  90  59 /  10   0   0   0
San Marcos Muni Airport        94  65  89  60 /  20   0   0   0
La Grange - Fayette Regional   92  66  88  61 /  20   0   0   0
San Antonio Intl Airport       95  69  90  64 /  10   0   0   0
Stinson Muni Airport           97  69  92  64 /  10   0   0   0

&&

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

$$

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