Special Weather Statement, NWS Austin/San Antonio, TX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
304 AM CDT Wed Mar 17 2021

.SHORT TERM (Today through Thursday)...
Three main topics in the short term: Lingering precipitation with
the front, the winds, and fire weather concerns. Lets talk about
that.

Models are in good agreement that the front by sunrise on Wednesday
should be east of the I-35 corridor, somewhere across the Coastal
Plains. High resolution models have trended much weaker with
convection along the front, likely due to a capped atmosphere ahead
of it, and the late nocturnal passage of the front. Still, even the
HRRR, which had been the most bullish of the high resolution models
until late yesterday, does show an isolated (potentially strong)
thunderstorm or two along or just behind the front around 7 am. SPC
did include our eastern areas in the new Day 1 Marginal Risk to
cover this low threat. Precipitation should quickly push east of the
area by mid-morning with clearing skies behind the front. Northwest
winds will help keep afternoon highs above normal in the mid 70s to
low 80s area wide. Tonight and tomorrow look cooler though with lows
in the 40s and highs Thursday in the low to mid 70s.

Those northwest winds will be gusty through the day, especially
across the Rio Grande Plains, Edwards Plateau, and Hill Country.
Sustained winds of 20 to 30 mph with gusts as high as 40 mph will be
possible. This has prompted the issuance of a Wind Advisory for most
areas west of Interstate 35 from late morning today through the
afternoon hours. Motorists in high profile vehicles should take
note, as well as those with lawn furniture, trash cans, and other
backyard objects that could get blown around this afternoon.

The winds will also contribute to higher fire danger across much of
the area today as dry air moves in behind the front. With afternoon
relative humidity values dropping and windy conditions expected most
of the area will see Near-Critical to Critical Fire Weather this
afternoon. The details of the expanded Red Flag Warning are
discussed in the Fire Weather section below, but needless to say
with the winds and dry cured fuels any grass or wildfires that do
develop today will spread quickly. Be extra careful if you work
outside with machinery that could produce sparks, are pulling a
trailer where the chains could spark a grass fire, and please don't
throw your cigarette butts out the window.

&&

.FIRE WEATHER...
Behind the front today winds will be breezy out of the northwest,
especially during the late morning and afternoon hours. Sustained
winds of 20 to 30 mph, with gusts as high as 40 mph are possible.
This will combine with relative humidity values dropping into the
teens across much of the Edwards Plateau and Rio Grande Plains to
produce Critical Fire Weather conditions. The Red Flag Warning has
been expanded to include Bexar, Wilson, and Karnes counties due to
low relative humidity values in these areas. Edwards, Real, Bandera,
and Kerr have also been added due to higher winds. Our Red Flag
Warning matches up fairly nicely with the Extreme and Very High
areas on the Texas Forest Service Fire Danger map for today. Near-
Critical Fire Weather will be possible across the Hill Country,
while elevated conditions should prevail elsewhere. Winds will
finally begin to subside this evening.

&&

.LONG TERM (Thursday Night through Tuesday)...
Thursday night will be relatively a chilly one for mid-March with
north winds falling to near 5 mph over most areas around daybreak.
North winds continue through Friday, but increased ridging aloft over
TX and sunny skies should get afternoon temperatures almost back to
mid-March normals. Near normal temps return by Saturday afternoon and
south winds returning will lead to warmer mins, higher dew point
temps, and pockets of morning stratus Sunday morning. Unsettled
weather develops early next week with a pair of upper low pressure
systems rotating through a broader trough over the Wrn CONUS. This
places South Central TX in a warm and moist regime with the potential
for spring storms. Typically this pattern means we'll probably see a
capping inversion difficult to overcome and daily PoPs that would
portray a wet pattern by the deterministic models. Will continue to
nudge rain chances downward into the 20-30 range for Mon/Tue.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              77  47  70  44  69 /  20   0   0   0   0
Austin Bergstrom Intl Airport  78  46  71  43  70 /  30   0   0   0   0
New Braunfels Muni Airport     79  48  72  43  71 /  30   0   0   0   0
Burnet Muni Airport            73  43  67  41  66 /  10   0   0   0   0
Del Rio Intl Airport           81  48  76  46  74 /   0   0   0   0   0
Georgetown Muni Airport        76  45  69  42  68 /  20   0   0   0   0
Hondo Muni Airport             79  45  76  42  74 /  -    0   0   0   0
San Marcos Muni Airport        78  46  71  42  69 /  30   0   0   0   0
La Grange - Fayette Regional   80  46  71  43  68 /  70   0   0   0   0
San Antonio Intl Airport       78  48  74  45  71 /  20   0   0   0   0
Stinson Muni Airport           79  47  75  44  71 /  20   0   0   0   0

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 10 AM this morning to 7 PM CDT this evening
for Atascosa-Bandera-Bexar-Dimmit-Edwards-Frio-Karnes-Kerr-Kinney-
Maverick-Medina-Real-Uvalde-Val Verde-Wilson-Zavala.

Wind Advisory from 10 AM this morning to 7 PM CDT this evening for
Bandera-Blanco-Burnet-Dimmit-Edwards-Gillespie-Kendall-Kerr-Kinney-
Llano-Maverick-Real-Uvalde-Val Verde-Williamson-Zavala.

&&

Short-Term/Aviation/Fire Weather...Treadway
Long-Term...Oaks

Hazardous Weather Outlook
National Weather Service Austin/San Antonio TX
340 PM CDT Tue Mar 16 2021

TXZ171>173-183>194-202>209-217>225-228-171100-
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-
340 PM CDT Tue Mar 16 2021

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

.DAY ONE...This Afternoon And Tonight.

A Pacific front will bring a line of thunderstorms tonight and
into Wednesday morning across the area. This activity has the
potential to be strong to severe with the main hazards being large
hail and damaging winds. Locations with the greatest risk for
these hazards are areas along the Edwards Plateau, Hill Country,
and along and west of the I-35 corridor.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Behind the front, late morning into afternoon on Wednesday, strong
northwesterly winds and low relative humidity values will lead to
critical fire weather conditions over our southwestern zones. The
areas of most concern are along and south of HWY 90 and west of
I-37 where a Red Flag Warning has been issued.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

Special Weather Statement
National Weather Service Austin/San Antonio TX
319 AM CDT Wed Mar 17 2021

TXZ171-172-188-170915-
Gillespie TX-Llano TX-Burnet TX-
319 AM CDT Wed Mar 17 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN GILLESPIE...LLANO
AND NORTHWESTERN BURNET COUNTIES UNTIL 415 AM CDT...

At 318 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 9 miles northeast of San Saba to 7 miles east
of Segovia. Movement was east at 30 mph.

Half inch hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Llano, Buchanan Lake Village, Castell, Field Creek, Cherry Spring,
Lone Grove, Enchanted Rock State Natural Area, Doss, Bluffton, Valley
Spring, Baby Head, Prairie Mountain, Stolz, Crabapple, Oxford, Tow
and Harper.

LAT...LON 3027 9896 3032 9930 3050 9930 3050 9896
      3092 9896 3092 9842 3094 9841 3095 9845
      3103 9844 3103 9820
TIME...MOT...LOC 0818Z 275DEG 27KT 3133 9866 3044 9954

MO