265
FXUS64 KEWX 160136 AAA
AFDEWX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
836 PM CDT Wed May 15 2024

...New UPDATE...

.UPDATE...
Issued at 821 PM CDT Wed May 15 2024

Removed thunderstorm activity across the Rio Grande for the rest of
the tonight period as a weak cap remains and likely to hold through
the period. We added for the late overnight hours close to dawn an
area of showers across the Rio Grande and southern Edwards Plateau as
surface to 5Kft level saturates.

&&

.SHORT TERM...
(Tonight through Thursday night)
Issued at 305 PM CDT Wed May 15 2024

High clouds continue streaming in from the west early this afternoon
as temperatures remain in the 80s to near 90 degrees. Despite the
high clouds, we should still manage to warm into the upper 80s to
upper 90s by late afternoon.

We will monitor the higher terrain west of the Rio Grande as the
latest round of hi-res models continue to suggest isolated storms
will develop and move eastward into the Rio Grande plains during the
very late afternoon or evening hours. There is a Marginal Risk
(level 1 of 5) for severe storms with large hail and damaging winds
being the main severe weather concerns. With the loss of daytime
heating, the chance for convection will decrease overnight. For
tonight, plenty of southeasterly flow in the low-levels will bring
an increase in moisture and result in widespread low cloud
development. With some slightly stronger 850mb southerly flow over
the region, will mention a low chance for light showers during the
pre-dawn hours across portions of the Hill Country. For the
remainder of the morning hours, a warm front will move northward
through the region and help bring an increasing chance for showers
and thunderstorms to most of south central Texas.

For the afternoon, the latest guidance shows an active pattern will
develop as a surface low and dryline moving across west central
Texas meets the unstable air near and south of the warm front during
peak heating. Thunderstorms will likely develop from west central
Texas into the Texas Hill Country by late afternoon. Initial
activity should be in the form of isolated supercells, with hi-res
model trends showing clusters of storms across the Hill Country into
portions of the I-35 corridor and coastal plains. SPC maintains a
Slight to Marginal Risk (level 1 to 2 of 5) for severe storms across
most of south central Texas, except for out west along the Rio
Grande. Large to very large hail and damaging winds will be the main
severe weather concerns. Areas along and north of a Kerrville to San
Marcos to Schulenburg line will be under the higher risk area for
severe storms. In addition, some locally heavy rainfall will be
possible in a fairly narrow corridor from south of Waco to near of
just north of Austin. A quick 1-2 inches with locally higher amounts
seems reasonable across Burnet, Williamson and Lee counties.
Rainfall amounts farther south will trail off rather quickly, with
only up to around 1/4 inch near San Antonio. A decrease in
convection should commence by late evening with the loss of daytime
heating.

&&

.LONG TERM...
(Friday through Wednesday)
Issued at 305 PM CDT Wed May 15 2024

The coastal plains east of I-35 has a slight chance of rain or a
storm through Friday afternoon pending the speed of the weak frontal
passage and with the last of the mid-level energy advancing across
the state. Elsewhere, it stays rain free with a dry heat across our
western zones while eastern areas remain more humid. The overnight
lows into Saturday morning will trend the lowest of the long term
ranging from the 60s into the low 70s.

Rain chances become minimal and heat builds through the rest of the
long term period as upper level ridging centered across Mexico to
our southwest strengthens with time. This heat is not absent of
humidity as surface high pressure to our east will allow for light
to moderate south to southeasterly winds to prevail. Only exception
from the humidity will be across our western zones where the heat
trends drier pending the location of the dryline. However, high
temperatures with the dry heat across those areas will easily rise
above 100 degrees each afternoon. Speaking of 100 degrees, some
locations near the I-35 corridor could potentially flirt with that
mark sometime early to middle of next week. Otherwise, peak heat
indices for locations with higher dew points are likely to top in
the 103 to 108 degree range or higher. Unfortunately, this sort of
heat is early again this year, and it`s time to think about those
heat safety precautions.

&&

.AVIATION...
(00Z TAFS)
Issued at 649 PM CDT Wed May 15 2024

All area terminals are forecast to remain VFR through the evening
period. MVFR are expected first across KDRT shortly after midnight
and for the I-35 airports around the 07Z-08Z time frame. IFR cigs are
anticipated for KSAT and KSSF through the 12Z to 18Z time window.
Kept the PROB30 mentioning TSRA for KAUS for the 20Z to 24Z time
frame on Thursday as a warm front pushes from the south into the Hill
Country area. VFR conditions return for all areas sites around 20Z
with the exception of KAUS.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              69  81  67  85 /  10  80  20  10
Austin Bergstrom Intl Airport  67  81  67  86 /  10  80  20  10
New Braunfels Muni Airport     69  85  69  88 /  10  60  20  10
Burnet Muni Airport            68  78  65  84 /  10  80  20  10
Del Rio Intl Airport           77 101  70 100 /  10  10  10  10
Georgetown Muni Airport        66  78  66  85 /  10  90  30  10
Hondo Muni Airport             70  88  67  93 /  10  30  10  10
San Marcos Muni Airport        67  83  67  87 /  10  70  20  10
La Grange - Fayette Regional   68  83  70  85 /  10  80  40  20
San Antonio Intl Airport       70  85  69  90 /  10  50  10  10
Stinson Muni Airport           72  87  71  90 /  10  50  10  20

&&

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

$$

Short-Term...17
Long-Term...04
Aviation...17