Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 09/19/23
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
615 PM CDT Mon Sep 18 2023
...New AVIATION...
.SHORT TERM...
(Tonight through Tuesday night)
Issued at 225 PM CDT Mon Sep 18 2023
Synopsis/Mesoanalysis: A cumulus field has broken out across the
area with warming surface temperatures early this afternoon. Said
cumulus have deepened into showers/isolated thundershowers over
portions of Hill Country and the southern Edwards Plateau. Current
radar imagery depicts mainly light-moderate echoes along and
northwest of a line extending from Uvalde to Boerne. This
development is likely linked to a subtle perturbation embedded
within northwest mid-level flow in place across the region. While
ill-defined in GOES water vapor imagery, said perturbation was
evident in this morning`s upper air charts, which indicated a subtle
area of height falls & cyclonic flow curvature at 500 mb along the
Front Range of the CO and NM Rocky Mountains. Stations along a line
extending from DRT-AMA-DDC reported minor height falls between 00Z
last evening and 12Z today, which likely explains why automated
analyses from the Storm Prediction Center have shown the narrow axis
of height falls continuing to progress east into Edwards Plateau &
TX Panhandle into this afternoon. Updrafts have struggled to
maintain themselves in an environment characterized by negligible
deep layer shear and weak mid-level lapse rates (as sampled by area
ACARS soundings), with intensity trends expected to remain
unimpressive through the remainder of today. Precip will dissipate
following sunset this evening. A west-northwest upper flow pattern
will continue to persist through tomorrow night, with the
subtropical ridge remaining suppressed over northwestern Mexico
until late week/the long term period. South-southeast winds will
prevail at the surface as the low levels respond to lee troughing to
our west, helping to raise dew points & humidity locally.
Remainder of Today & This Evening: Widely scattered
showers/thundershowers will continue over primarily Hill Country and
the southern Edwards Plateau. Expect the bulk of activity to remain
confined to this portion of the area, where proximity to the subtle
shortwave discussed above is greatest. Can`t entirely rule out an
isolated shower/thundershower along portions of the I-35 Corridor
from New Braunfels to San Antonio, though confidence in this
occurring is lower. High temperatures in the low to mid 90s are
expected, though a few locations in Hill Country may remain in the
upper 80s. Any showers/thundershowers will dissipate quickly
following sunset.
Tomorrow: Temperatures will likely be a couple degrees warmer
relative to today, with mid-nineties expected in most locations
outside of Hill Country. A few locations near the Rio Grande could
reach the upper 90s. Dew points will be slightly higher with
southeast flow entrenched at the surface, which may lead to
conditions feeling muggier to some. The 12Z CAM suite depicts at
least scattered shower/storm development near the lee trough axis
from the Big Bend northeast into the Edwards Plateau during the
afternoon hours, though activity is expected to dissipate prior to
reaching our northwestern zones. Will continue to monitor for any
potential changes to this expected solution over coming forecast
cycles.
&&
.LONG TERM...
(Wednesday through Monday)
Issued at 225 PM CDT Mon Sep 18 2023
The sub-tropical ridge will be situated across northern Mexico and
south Texas through the long term period. In general, this will
result in continued above normal temperatures and mainly dry
conditions, though there will be daily low-probability chances for
showers and storms just about each day. The blended guidance keeps
Wednesday dry but includes mentionable PoPs beginning on Thursday
along the seabreeze for the Coastal Plains. For Thursday night into
Friday, guidance shows a shortwave riding around the northern
periphery of the ridge, which could result in some isolated shower
and storm activity across portions of the CWA during this timeframe.
Then, focus will shift back to the Coastal Plains/seabreeze for
Friday afternoon.
The forecast becomes a little less certain heading into/through the
weekend as a 500mb trough is progged to eject from the Great Basin,
across the Rockies, and into the northern/central Plains. This will
send a cold front south into the Southern Plains and help flatten
the ridge overhead, but a fair amount of uncertainty exists
regarding where the front will stall across Texas. While the exact
location will be difficult to fine tune without hi-res guidance,
indications are the front may stall somewhere across south-central
Texas during the Sunday to Monday timeframe which would bring the
best chances for precipitation through the long term period and some
slightly cooler temperatures.
&&
.AVIATION...
(00Z TAFS)
Issued at 613 PM CDT Mon Sep 18 2023
VFR conditions will prevail with sct clouds currently around 7-10kft.
Winds will remain light through the period with speeds generally less
than 12 knots from the south/southeast. Should see a bit higher
speeds for DRT in the afternoons. Otherwise, no major impacts are
expected for this TAF cycle.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 71 95 72 97 / 0 0 0 0
Austin Bergstrom Intl Airport 70 95 71 95 / 0 0 0 0
New Braunfels Muni Airport 71 96 72 98 / 0 0 0 0
Burnet Muni Airport 71 93 72 95 / 0 0 10 0
Del Rio Intl Airport 74 98 75 101 / 0 0 0 0
Georgetown Muni Airport 71 94 72 96 / 0 0 0 0
Hondo Muni Airport 69 95 70 97 / 0 0 0 0
San Marcos Muni Airport 69 95 70 97 / 0 0 0 0
La Grange - Fayette Regional 70 94 71 94 / 0 0 0 10
San Antonio Intl Airport 72 96 73 97 / 0 0 0 0
Stinson Muni Airport 73 97 74 98 / 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...Quigley
Long-Term...Gale
Aviation...29