572
FXUS64 KEWX 211842
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
142 PM CDT Tue May 21 2024

...Heat Wave Intensifies Into and through Memorial Day Weekend...

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(Tonight through Wednesday night)
Issued at 140 PM CDT Tue May 21 2024

A few locations will likely briefly reach or exceed Heat Advisory
criteria this afternoon, though the previous shift issued a
widespread Special Weather Statement to cover this threat and no
changes will be made there. Otherwise this afternoon/evening, an
isolated storm may try to develop in the vicinity of
Llano/Gillespie/Burnet Counties which could briefly become
strong/severe. There is low confidence in this occurring, but just
enough confidence to add in a 10% PoP with weather mentioned into
the forecast grids.

Low clouds will then redevelop overnight with some areas of minor
reduced visibility likely noticeable around and shortly after sunset
due to a combination of moisture and smoke from Mexico/Central
America trapped near the surface. The temperature and heat index
forecast for tomorrow looks pretty similar to today, so a few
counties may need a Heat Advisory or at least another fairly
widespread Special Weather Statement, though we will let the
overnight shift make that decision again for tomorrow. Slightly
better chances for storms are in the forecast for mainly Hill
Country areas tomorrow afternoon/evening as a weak disturbance in
the 500mb flow moves overhead across portions of north and central
Texas. The better chances for storms will be to the north of our
CWA, though any storms that develop or move into our counties will
have the potential to be severe with large hail and damaging wind
gusts being the main threats.
&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 140 PM CDT Tue May 21 2024

Thursday stays hot but Friday through Memorial Day will see the
early season heat and humidity become even more oppressive across
South-Central Texas. Mid-level ridging centered across Mexico will
intensify and nudge a bit more into the state. Additionally, soil
moisture levels from precedent spring rains and a light to moderate
south-southeasterly onshore flow off the gulf with surface high
pressure to our east should also allow for elevated dew points to
remain across the area. Both daily record maximum temperatures and
daily record high minimum temperatures could be threatened and/or
broken this weekend in some locations. The highs along the Rio
Grande will climb into the 105 to 110 degree range each afternoon
while elsewhere the upper 90s and into the 100 to 105 degree range
will become common. The heat indices will run even higher for the
majority of the region with peak values ranging from 105 to 115
degrees. Heat products are likely necessary from Friday through
Memorial day, including Heat Advisories and/or Excessive Heat
Warnings. Those that are spending an extended time outdoors this
holiday weekend and not acclimated to the early season heat are
susceptible to heat related illness, if not taking proper heat
precautions.

Heat Precautions: Never leave people or pets alone within a closed
car, stay hydrated by drinking plenty of water, wear loose-fitting
and light colored clothing, and take frequent breaks within the
shade and air conditioning.

Late Thursday afternoon into Thursday evening has a low chance (15-
20%) for a shower or storm across our northern most Hill Country
counties. Chances are to decline into the 10 percent or less range
from Friday into Monday. Slight chances (15-20%) return starting
Monday night and Tuesday in association with a southward moving
front and any associated outflow boundaries. These boundaries also
look to potentially relieve some of the worse of the heat into
Tuesday as well.

&&

.AVIATION...
(18Z TAFS)
Issued at 1229 PM CDT Tue May 21 2024

VFR conditions will prevail this afternoon and evening as heating
scatters out the cloud deck. However, MVFR clouds will redevelop
overnight and linger through Wednesday morning. There could at times
be some reduced visibility due to a mix of BR and smoke from fires in
Mexico, mainly noticeable during the morning hours. Winds will remain
out of the S/SE.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              77  94  76  93 /  10  30  10  10
Austin Bergstrom Intl Airport  76  93  75  92 /  10  20  10  10
New Braunfels Muni Airport     76  96  75  95 /   0  20  10  10
Burnet Muni Airport            75  90  73  90 /  10  30  20  20
Del Rio Intl Airport           81 103  80 106 /  10  10  10   0
Georgetown Muni Airport        76  92  74  91 /  10  30  10  10
Hondo Muni Airport             76  99  74  99 /  10  10  10   0
San Marcos Muni Airport        76  95  74  93 /  10  20  10  10
La Grange - Fayette Regional   78  92  76  91 /   0  10   0   0
San Antonio Intl Airport       77  96  76  95 /   0  20  10   0
Stinson Muni Airport           78  97  77  96 /   0  20  10   0

&&

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

$$

Short-Term...Gale
Long-Term...Brady
Aviation...Gale