655
FXUS64 KEWX 101109
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
609 AM CDT Mon Jun 10 2024

...New AVIATION...

.SHORT TERM...
(Today through Tuesday)
Issued at 251 AM CDT Mon Jun 10 2024

Early morning radar trends show one area of convection weakening over
eastern Bexar/western Guadalupe counties. Elsewhere, another area of
convection continues over Val Verde and Edwards counties, along with
some weak radar echoes developing farther east into the Hill Country
across northern Kerr county. Rain chances through most of the
morning hours have been based largely on radar trends and adjusted
upward across the southern Edwards Plateau and western Hill Country.
While a few strong to marginally severe storms are possible, most
activity should remain below severe limits. Some locally heavy
rainfall can be expected given healthy precipitable water values and
weak steering flow.

The latest model guidance has trended upward with regard to rain
chances across south central Texas today. A fairly weak, but broad
upper low over far west Texas into southern New Mexico will slowly
drift northward today. On the southern edge of this low, some weak
upper disturbances embedded in the weak west/northwest flow aloft
will move into the region. With daytime heating and outflow
boundaries from ongoing convection, we expect to see additional
showers and storms today. We have opted to increase rain chances over
the NBM given the pattern we are in. While model solutions vary, we
have enough confidence to boost rain chances into the 30-50% range
for most of the region today. We may need to trend these values
upward (southern Edwards Plateau/Rio Grande plains?) if we start to
see signs of MCV development from the ongoing activity.

For tonight, most areas should see a decrease in coverage of
convection. The models do favor some overnight activity moving down
from west central Texas into portions of the western Hill Country,
southern Edwards Plateau and perhaps the Rio Grande plains. We will
keep some low rain chances here, but again may need to boost pending
model trends. The slow-moving upper low begins to move southward out
of the Texas Panhandle into northwest Texas on Tuesday. Convection
should be mostly isolated Tuesday afternoon, with models favoring the
Hill Country and nearby I-35 corridor near and north of Austin. Given
the fairly weak flow aloft, chances for a few strong to marginally
severe storms will remain low. However, above normal moisture and
overall weak steering flow will pose a locally heavy rainfall
concern, especially where multiple rounds of showers and storms
occur. With the increased rain chances, we will keep highs mostly in
the 90s today and tomorrow. The exception being out west along the
Rio Grande, where some highs may approach 100 degrees.

&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 251 AM CDT Mon Jun 10 2024

An increase in mid-level disturbances associated with the above
mentioned upper low are expected to move out of west central Texas
into portions of central Texas Tuesday night into Wednesday. A fair
amount of the models show some of the higher rainfall totals during
the late Tuesday night/early Wednesday morning time frame over the
Hill Country and southern Edwards Plateau. We have increased rain
chances over this region and will likely need to make additional
adjustments depending on what occurs from previous rounds of
convection. Some pockets of heavy rainfall are likely to develop, but
the exact location remains in question. For now, the models tend to
favor the Hill Country, but some of this could also drop southward
into the I-35 corridor. Given the ongoing areas of drought across the
Hill Country, portions of the I-35 corridor and Rio Grande plains,
some areas we are hopeful for some localized improvement in drought
conditions. If the pattern manages to develop as expected, highs on
Wednesday may only peak in the upper 80s to lower 90s across the Hill
Country and a decent portion of the I-35 corridor. If the upper low
trends a little slower in subsequent model runs, we may need to add
some rain chances to the forecast for Wednesday night.

With the subtropical ridge axis quickly building in from the west
during the latter half of this week, temperatures are expected to
trend upward. In addition, we will keep the forecast dry through the
mentioned period. Highs on Thursday will range from the lower 90s to
near 100 degrees. These values will increase into the mid 90s to
near 105 degrees for the upcoming weekend. Overnight lows are largely
expected to remain in the 70s.

&&

.AVIATION...
(12Z TAFS)
Issued at 608 AM CDT Mon Jun 10 2024

A thunderstorm complex continues to move towards SAT/SSF, expected
to be over these sites for the start of the period. Showers and
occasional lightning behind the main line may linger though 14Z.
Some isolated activity on the backside of this complex may move over
DRT through 14Z as well. Dry weather continues for AUS through the
morning. Isolated thunderstorm development may be possible this
afternoon if the atmosphere can destabilize again after this initial
complex. For now, have included VCTS at I-35 sites after 19-20Z, but
will need to watch trends as this timing may need to be pushed back.
Another complex will be possible in the west tonight with a PROB30
group included at DRT around 03Z to account for that scenario. VFR
conditions should continue this period except for with thunderstorm
activity which could drop sites briefly to IFR or LIFR.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              94  74  93  73 /  30  20  10  30
Austin Bergstrom Intl Airport  93  73  93  72 /  30  20  10  30
New Braunfels Muni Airport     95  74  96  73 /  30  20  10  30
Burnet Muni Airport            90  73  90  71 /  40  20  20  40
Del Rio Intl Airport           98  79 101  80 /  30  20   0  20
Georgetown Muni Airport        91  73  91  71 /  40  20  20  30
Hondo Muni Airport             95  74  96  74 /  30  20  10  30
San Marcos Muni Airport        93  73  93  72 /  30  20  10  30
La Grange - Fayette Regional   92  74  91  73 /  30  20  20  30
San Antonio Intl Airport       95  75  95  75 /  30  20  10  30
Stinson Muni Airport           96  76  97  76 /  30  20  10  30

&&

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

$$

Short-Term...29
Long-Term...Platt
Aviation...27