Wildfire in Texas, September 4 to 10, 2023

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
556 PM CDT Mon Sep 4 2023

...New AVIATION...

.SHORT TERM...
(Tonight through Tuesday night)
Issued at 150 PM CDT Mon Sep 4 2023

RAP analysis depicts the upper low in E OK, with model guidance
showing it opening up this afternoon as it begins the process of
getting picked up by the trough to our northwest. It should
gradually exit to the northeast through tonight, with subtropical
ridging building over the southern CONUS and northern Mexico through
the rest of the short term.

Onshore low level flow over the middle and upper TX coast is leading
to some shower and storm activity today, but this should only impact
our far eastern counties with minimal, isolated rainfall amounts. As
the sea breeze pushes inland this evening, the NAM and it's nest
continue to point towards a low potential for an isolated storm to
develop along it in the greater San Antonio area. Most other
guidance doesn't buy into this, though the FV3 does have an evening
storm in the Atascosa County area, and even the HRRR is beginning to
get into the game with a few evening cells just east of I-35 in the
Coastal Plains. A 10% chance has been added to the forecast from 7-
10pm for portions of the region to cover this possibility, and may
need to be pushed up to 20% in future updates.

Otherwise, temperatures and heat indices should remain just below
heat advisory thresholds for the most part, so will let the SPS ride
today. Heat Indices may briefly exceed 108 in mainly Lavaca/DeWitt
Counties, but with some more cloud cover and rain chances and a
looooong summer of heat, will stick with the SPS there as well.
Similar conditions are expected tomorrow, with again a low chance
for a shower/storm over the US-77 corridor. At this time, do not
anticipate a Heat Advisory for tomorrow but cannot completely rule
it out.

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 150 PM CDT Mon Sep 4 2023

The subtropical high continues to build across west Texas on
Wednesday while an upper level trough axis pushes across the coastal
plains. The combination of daytime heating along with the trough
axis could produce isolated shower and thunderstorm activity across
the coastal plains in the afternoon period. Otherwise, expect hot
weather conditions with highs in the mid 90s and up to 104 degrees.
A few areas are likely to reach heat advisory criteria for a short
period of time, but nothing widespread this far out. We will closely
monitor this situation.

The warming trend continues on Thursday into Friday as the
subtropical high slightly moves to the east. This scenario brings
drier and hotter weather conditions are the local area. Thursday's
high range from the upper 90s across the Hill Country and 103 to 105
along the I-35 corridor including the Austin metro area and the
coastal plains. Similar conditions are expected for Friday with highs
reaching up to 107 degrees over a few spots. Heat headlines are
likely issued for Thursday and Friday during the middle of the week
if weather guidance remain suggesting this hot weather period.

The subtropical high weakens a little bit for next Saturday as an
upper level shortwave axis pushes across east Texas and another
upper level shortwave moves across east Texas on Sunday afternoon.
With plenty of hot weather conditions in addition to some
instability in place, expect isolated shower or thunderstorm
activity across the Hill Country, I-35 and interstate 35 mainly in
the afternoons through the early evening hours.

Overall dry and hot weather conditions are helping near critical
fire weather conditions across the local area for the next five to
seven days. More details below in the Fire Weather section.

&&

.AVIATION...
(00Z TAFS)
Issued at 556 PM CDT Mon Sep 4 2023

Scattered mid-level clouds continue over the eastern half of South-
Central Texas for the start of the period. The seabreeze is
beginning to move inland which will bring some breezy southeast wind
this evening with gusts up to near 23 knots possible through
midnight. A few storms may develop in the Coastal Plains through
03Z, but look to remain well east of I-35 sites. A period of MVFR
ceilings returns to I-35 sites around 08-09Z, possibly lingering as
long as 15Z. VFR conditions will remain through the period at DRT.

&&

.FIRE WEATHER...
Issued at 150 PM CDT Mon Sep 4 2023

Some slightly higher moisture is sticking around today compared to
the past few days. Portions of the area, mainly in the Hill Country
and southern Edwards Plateau, will see minimum humidity between 20
to 30 percent this afternoon. Even with this small uptick in
moisture, dry to critically dry fuels and southeasterly wind around
10 mph will continue to bring elevated to near critical fire weather
conditions through this evening. A Fire Danger Statement remains
effect through 9 PM this evening over these areas. Slightly more
moisture is seen tomorrow, especially for the western Hill Country
and southern Edwards Plateau. However, winds will be 1-3 mph
stronger tomorrow afternoon, and another Fire Danger Statement may
be needed for portions of the area. Will let the midnight shift
assess forecast trends given the borderline weather situation.

Low relative humidity values are forecast to range from 20 to 30
percent on Thursday across most areas and down to the teens on Friday
across the Hill Country and southern Edwards Plateau. Wind speeds are
likely to range from 7 to 12 mph mainly in the afternoons and early
evening hours. With that said, Fire Danger Statements will be likely
issued in the upcoming days as most of the local area's fuel dryness
levels range from dry to critically dry.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              78 103  77 103 /   0  10   0  10
Austin Bergstrom Intl Airport  78 102  76 102 /   0  10  10  10
New Braunfels Muni Airport     78 103  77 103 /  10  10  10  10
Burnet Muni Airport            77 101  76 101 /   0   0   0   0
Del Rio Intl Airport           80 104  80 102 /   0   0   0   0
Georgetown Muni Airport        78 102  76 102 /   0   0   0  10
Hondo Muni Airport             75 101  75 100 /  10   0   0  10
San Marcos Muni Airport        77 102  74 102 /  10  10   0  10
La Grange - Fayette Regional   79  99  77 100 /  10  20   0  20
San Antonio Intl Airport       78 101  78 101 /  10   0  10  10
Stinson Muni Airport           79 102  78 102 /  10   0   0  10

&&

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

Short-Term...KCW
Long-Term...17
Aviation...27

Hazardous Weather Outlook...CORRECTED
National Weather Service Austin/San Antonio TX
346 AM CDT Mon Sep 4 2023

TXZ171>173-183>194-202>209-217>225-228-050845-
Llano-Burnet-Williamson-Val Verde-Edwards-Real-Kerr-Bandera-
Gillespie-Kendall-Blanco-Hays-Travis-Bastrop-Lee-Kinney-Uvalde-
Medina-Bexar-Comal-Guadalupe-Caldwell-Fayette-Maverick-Zavala-
Frio-Atascosa-Wilson-Karnes-Gonzales-De Witt-Lavaca-Dimmit-
346 AM CDT Mon Sep 4 2023

This Hazardous Weather Outlook is for South-Central Texas..

.DAY ONE...Today And Tonight.

Near critical fire weather conditions are possible this afternoon
over the southern Edwards Plateau, Hill Country, and I-35
Corridor. A Fire Danger Statement is in effect between noon and 9
PM in light of this potential.

A combination of hot high temperatures and increased dew points
will lead to elevated heat indices primarily along and east of
I-35 this afternoon. Practice proper heat safety if planning to be
outdoors over this portion of South-Central Texas today.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Near critical fire weather conditions will continue to remain
possible through at least mid-week given low relative humidities,
breezy winds, and critically to extremely dry fuels.

Elevated heat indices are expected once again on Tuesday
afternoon along & east of I-35 and over portions of the Rio Grande
Plains, with some locations possibly approaching Heat Advisory
thresholds. Humidity will trend down by late week, though high
temperatures are likely to increase to Heat Advisory levels in
spots. Heat headlines are thus possible tomorrow, and once again
later this week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.