Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX

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FXUS64 KEWX 171133
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
633 AM CDT Wed Apr 17 2024

...New AVIATION...

.SHORT TERM...
(Today through Thursday)
Issued at 319 AM CDT Wed Apr 17 2024

The dryline has retreated back west of the area and dew points
through the western Hill Country and Rio Grande have surged into the
mid to upper 60s. Stratus will continue to expand across south-
central through the overnight and early morning hours. The low
clouds will scatter out along the Rio Grande by midday, but will be
slower to scatter out farther east into the I-35 corridor and
eastern Hill Country. Combined with abundant cirrus streaming
through the region, skies will remain mostly cloudy today. High
temperatures are forecast in the mid 80s east to low to mid 90s
along the Rio Grande.

An upper level trough will continue to dig south across Baja
California today and tonight, then dampen east across interior
Mexico on Thursday. Ahead of this feature, a weak impulse in the
west to southwest flow aloft could initiate isolated, elevated
showers and storms out of Mexico and south Texas, possibly clipping
the Winter Garden and Coastal Plains this evening. Isolated surface
based convection is also possible along the dry line to the west and
northwest as well as in the higher terrain of Mexico. Some
convective allowing models are indicating a potential for this later
convection to reach the Rio Grande and southern Edwards Plateau as
the cap tries to briefly erode late afternoon and early evening. If
this were to occur, a strong storm or two can`t be ruled out in this
region, producing gusty winds and small hail. Overall, coverage of
storms should remain isolated across this region.

Stratus is expected to re-develop late this evening beneath the cap
across the Coastal Plains and I-35 corridor, expanding west
overnight and into Thursday morning. The low clouds will again
scatter out west to east late morning into the afternoon on
Thursday, with warmer conditions expected. High temperatures in the
upper 80s to lower 90s east to upper 90s west are forecast.

The dryline is forecast to bulge farther eastward late Thursday
afternoon into the southern Edwards Plateau, while to the north a
cold front drops south into central Texas. Convection is expected to
initiate along the cold front to the north mid to late Thursday
afternoon, possibly entering far northern areas up near Williamson,
Burnet, Llano, and Gillespie counties just before the end of this
short term period. Farther southwest, closer to the dryline and in
the higher terrain of Mexico, it`s less certain if isolated
convective initiation takes place late Thursday afternoon, although
a few CAMs do show this near the Rio Grande. Some storms approaching
from the north across central Texas, as well as near the Rio Grande,
could become severe late Thursday afternoon. Currently SPC has Level
1 out of 5 risk for severe storms on Thursday afternoon and night in
a corridor near and west of an Austin to Eagle Pass line, with a
Level 2 out of 5 risk just north of the area. Large hail and
damaging wind gusts are the main threats. See long term
discussion below for details on storms into Thursday evening.

&&

.LONG TERM...
(Thursday night through Tuesday)
Issued at 319 AM CDT Wed Apr 17 2024

A relatively active period of weather is expected for the long term
period, especially for this weekend as a more typical cold front
pushes into the region (compared to the Pacific fronts we`ve been
seeing).

The first chance for showers and storms (albeit a low chance) will
be ongoing at the beginning of the period for Thursday evening. The
cold front mentioned above will be pushing into northern portions of
the state during the day Thursday which is expected to result
convection primarily developing along the boundary in the north
Texas/DFW vicinity. Secondary areas of development that some CAMs
are hinting on will be along a dryline across the Edwards
Plateau/northwestern Hill Country and along the SDB Mountains in
Mexico. These secondary areas will be the ones to focus on for
potential impacts to south-central Texas, and SPC has a level 1 out
of 5 risk in place for severe thunderstorms capable of large hail
and damaging wind gusts. At this time, shear looks to be more on the
marginal end, but there will be plenty of CAPE to help compensate.

This front will continue to slowly drift southward into the local
area, and will become the focus for shower and thunderstorm
development late Friday into early Sunday as a shortwave
simultaneously ejects east out of northern Mexico. The extent of the
severe threat with these storms is still a little uncertain as winds
aloft will not be particularly strong, though models are in fairly
good agreement with the potential for some heavy rainfall,
especially over the northern half of the CWA. To address this
threat, WPC has placed much of the northern half of the CWA in a
level 2 out of 4 threat for excessive rainfall/potential flash
flooding, with a level 1 out of 4 threat for the remainder of the
area.

The front will eventually push south of the area Sunday morning
which will bring decreasing precipitation chances and cooler
temperatures, with many locations along and north of I-10 forecast
to remain in the 60s for Sunday afternoon. Temperatures will then
gradually recover through the beginning of next week with dry
conditions currently forecast until at least next Wednesday.

&&

.AVIATION...
(12Z TAFS)
Issued at 633 AM CDT Wed Apr 17 2024

Low stratus prevails across most of the region, with the exception of
out near DRT. The stratus was producing a mix of LIFR and IFR
conditions. Ceilings will rise 15Z-19Z back into VFR while BR
dissipates. Isolated SHRA/TSRA activity is possible late this
afternoon and evening along the Rio Grande and southern Edwards
Plateau. A PROB30 TSRA has been included in the DRT TAF from 22Z-04Z.
Stratus re-develops late this evening and into the early morning
hours on Thursday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              87  71  89  68 /  10  10  20  20
Austin Bergstrom Intl Airport  86  70  88  66 /  10  10  10  20
New Braunfels Muni Airport     86  70  91  68 /   0  10  10  20
Burnet Muni Airport            85  70  88  65 /  10  10  30  20
Del Rio Intl Airport           95  75  99  72 /  10  20  30  10
Georgetown Muni Airport        86  70  88  66 /  10  10  20  20
Hondo Muni Airport             87  70  94  66 /   0  10  20  10
San Marcos Muni Airport        86  70  90  66 /  10  10  10  20
La Grange - Fayette Regional   86  72  86  69 /  10  10  10  10
San Antonio Intl Airport       86  71  91  68 /   0  10  10  20
Stinson Muni Airport           87  72  92  69 /  10  10  10  20

&&

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

&&

$$

Short-Term...76
Long-Term...Gale
Aviation...76


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