054
FXUS64 KEWX 120549
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1249 AM CDT Fri Jul 12 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Friday night)
Issued at 224 PM CDT Thu Jul 11 2024

An area of weakness remains in the upper levels over South Central
Texas today and tomorrow allowing high PWATS to remain over much of
Texas. A few showers have developed over the Rio Grande Plains
midday with more isolated to widely scattered activity expected to
develop mid afternoon ending sometime around sunset. Similar to
previous days, bulk shear is lacking which should keep storms non-
severe, although locally heavy rain and gusty wind will be possible.
The most favored locations for any precipitation will be south of I-
10. Highs today will top out in the low to upper 90s, near seasonable
values for mid-July.

Friday, an inverted trough builds over the the western portion of
the area which will aid in more widespread precipitation chances
over the area beginning in the morning. By Friday afternoon, PWATS
will generally be from 1.5 to 2.25 inches across all of South
Central Texas which will bring another day of locally heavy rainfall
and gusty wind. PoPs will be highest in the southern half of the CWA
although scattered showers or thunderstorms may develop as north as
the Hill County Friday afternoon. A bit more coverage for storms is
expected tomorrow compared to today. Increased cloud cover could
cool us off a few degrees tomorrow, although highs are still
expected to reach into the upper 80s to mid 90s areawide.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 224 PM CDT Thu Jul 11 2024

The long-term period of the forecast will continue to see some low
chances of rain for portions of the area as a weak upper low slowly
meanders west of our CWA. This upper low is the remnants of a weak
wave that moved in from the western Gulf earlier in the forecast
period. Saturday will likely see the highest chances of rain during
the long-term as the low is closest to the CWA and precipitable
water values remain near 2 inches. Will show some 30-40 PoPs in the
Coastal Plains where the moisture is highest and in the western CWA
in closer proximity to the low. The rest of the CWA will see 20-30
PoPs. The upper low should retreat a bit to the west Sunday and
Monday with lower moisture values expected. This should allow for
lower PoPs with some 20s in the forecast for the extreme west and
southeast counties. The GFS/ECMWF have some differences with how far
the low will move to the northwest with the ECMWF farther north.
Rain chances will be mainly dependent on the location of the low but
will keep most of the area dry Tuesday into Wednesday with maybe
some low chances continuing in the southeast and northwest CWA. The
best timing for rain on any given day through Wednesday will be
mainly in the afternoon periods with peak diurnal heating. Most
activity should dwindle in the evenings with the loss of heating.

The GFS/ECMWF are in somewhat of agreement that a trough will push
through the Central Plains late next week and should push a boundary
into Texas during this time frame. The GFS sends this boundary into
our area while the ECMWF keeps it mainly north. It is hard to get a
front this far south during the month of July, but regardless should
see a slight increase in PoPs for portions of the area perhaps on
Thursday or just beyond the current forecast cycle with the lack of
high pressure over our region. Will continue to monitor for any
trends here. Temperatures in the extended will mostly be in the 90s
Saturday through Monday with possible highs near 100 by mid-week as
the atmosphere dries out a bit. Lows will be in the 70s for most
locations.

&&

.AVIATION...
(06Z TAFS)
Issued at 1241 AM CDT Fri Jul 12 2024

VFR skies should predominate the TAF periods over the next 24 to 30
hours, but a flux of higher moisture content from the south could
bring a few more pockets of MVFR ceilings into mainly the San Antonio
area close to daybreak. The low cigs shouldn`t last more than just a
few hours. Increasing PWat values from the south into the Highway 90
corridor could give SSF/SAT an increasing chance of convection as
early as noon. We show the longest period of Prob30 groups here, and
a need to go TEMPO may take shape if we see the radar echoes lighting
up to the south by 11Z. Isolated convection is possible a couple
hours later at DRT/AUS and a smaller time window of Prob30 convection
is offered at those sites. Main reason to include this period is to
account for outflow winds as the core of brief heavy downpours will
be much harder to pin down. By around 02Z most of the convection
should wane, at least around the TAF locations. Non-outflow winds
from the E/SE could pick up to near 10 knots in the mid afternoon at
any of the TAF sites, but most of the night and morning winds should
remain around 8 knots or lower with variable directions at times.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              76  95  77  97 /  10  20   0   0
Austin Bergstrom Intl Airport  75  93  76  96 /  10  20   0   0
New Braunfels Muni Airport     75  94  76  96 /  10  30   0   0
Burnet Muni Airport            74  92  75  95 /  10  20   0   0
Del Rio Intl Airport           77  92  78  96 /  20  40  20  10
Georgetown Muni Airport        75  93  76  96 /  10  20   0   0
Hondo Muni Airport             75  90  75  94 /  20  30  10   0
San Marcos Muni Airport        73  93  75  95 /  10  20   0   0
La Grange - Fayette Regional   74  91  74  94 /  10  30   0   0
San Antonio Intl Airport       76  93  77  95 /  20  30  10   0
Stinson Muni Airport           76  93  77  96 /  10  30   0   0

&&

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

$$

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