Special Weather Statement, NWS Austin/San Antonio, TX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
1109 PM CDT Sat May 21 2022

...New UPDATE...

.UPDATE...
Issued at 1102 PM CDT Sat May 21 2022

A new Severe Thunderstorm Watch has been issued for areas along and
southeast of I-35 and along and south of US-57 through 4 AM Sunday.
Strong to severe thunderstorms continue to develop along the cold
front pushing across our area. Main weather threats are large hail
and damaging thunderstorm wind gusts.

The earlier Severe Thunderstorm Watch for the northern part of the
Hill Country, southern Edwards Plateau and Rio Grande was allowed to
expire at 11 PM as storms moved southeast of these areas.

&&

.UPDATE...
Issued at 944 PM CDT Sat May 21 2022

Severe weather threat for Edwards County shifted to the southeast and
therefore the cancellation of the Severe Thunderstorm Watch for the
county. However, the strong to severe thunderstorm threat continues
for areas along the I-35 corridor through 11 PM.

&&

.SHORT TERM...
(Tonight through Sunday night)
Issued at 124 PM CDT Sat May 21 2022

Another hot day across the region where record high temperatures
will again be threatened for the I-35 climate sites. With the dew
points in the mid to upper 60s and low 70s, heat indices will peak
in the 101 to 108 degree range for many today. Satellite imagery
shows the region is mostly sunny with a batch of passing mid-level
cumulus. Cumulus field is beginning to get more agitated north of
our CWA across portions of Mason and San Saba counties in the
location of our approaching cold front. Over the next few hours,
expect isolated to scattered convection to develop across the Hill
Country. Convective allowing models show the activity generating
into a broken line that will advance southeastward toward the I-35
corridor into and through this evening along the front or outflow
advancing ahead of the frontal boundary. The isolated to scattered
convection could become strong to severe given moderate to high
instability and steep low to mid-level lapse rates. Shear is weak
but sufficient enough to maintain organized convection. Main hazards
will be large hail and strong damaging winds. The majority of the
guidance show the activity waning through the overnight where only
isolated post-frontal showers may linger and start to concentrate
most along the Rio Grande where the highest PWATs will reside. Few
convective allowing models, however, do show a possible secondary
round of convection with the presence of possible outflow driven
cold pools.

Warm and humid conditions persist ahead of the front under a light
to moderate south-southeasterly flow. Behind the front, expect for
moderate north-northeasterly winds, which will help to advect a
cooler airmass into the region. This will lead to a cooler morning
and a much cooler day on Sunday across the region underneath the
mostly cloudy skies. The afternoon high temperatures are to range
from the low to mid 70s across the Hill Country to the mid 80s for
our southern counties. Outside from lingering post-frontal shower
activity, much of the area should see a lull in activity on Sunday
ahead of the arrival of the upcoming the more unsettled and wet
pattern early next week.

Overnight Sunday night into Monday morning should see rain chances
start to bump back upwards out west along the Rio Grande with the
approach of an upper level disturbance and our next weather maker.
See the long term below for details as this system moves in from
Monday through Monday night.

&&

.LONG TERM...
(Monday through Friday)
Issued at 124 PM CDT Sat May 21 2022

Sunday night begins cool and mostly stable, although some weak and
elevated convection can't be ruled out. Continued upstream troughing
to the west of TX brings a warm front into the Rio Grande Valley by
Sunday night with a widespread coverage event possible starting by
09Z Monday and continuing through 18Z Tuesday and featuring multiple
rounds. There will likely be a break or two between rounds of rain
during this period, but a large scale MCS is forecast to coincide
with compact mid level low pressure system Monday night. This could
be excellent news for most of us wanting rain, but there could be
some excessive amounts as depicted in the slight risk area by the
WPC. Forecast Pwat values are not particularly high for this pattern,
but the mid level dynamics will likely create the locally heavy
pockets and possibly lead to slow moving or training cells. Should
any storm clusters dump large amounts of rain in the short-term, we
may see a few areas go from extreme to extraordinary drought to a
localized threat for flash flooding. For the month of May, this
should come as no surprise to those that have lived here long enough.

Lapse rates should become quite steep beneath the mid-level low, but
a limiting factor might be the deep moisture profile through 12KM.
CAPES should be curbed to mostly below 3000 J/Kg and with light to
moderate shear for what will probably be a Marginal Risk for severe
weather as is already shown for the Day 3 Outlook. Assuming this
compact system delivers a solid round of rain, there should be a
period of worked-over air for Tuesday night. However, another lobe
of the upper trough and another cold front to arrive Wednesday, means
one last good round of rain chances should appear before we head back
to drier weather. We'll message storm total rains to peak at around 5
inches for now, and revise upward should the early rain rounds
deliver at or above what we suggest.

Thursday will benefit from the second cold front and pleasant weather
forecast for late May standards. So enjoy while you can. Highs in
the 90-97 range could return by next Saturday.

&&

.AVIATION...
(00Z TAFS)
Issued at 632 PM CDT Sat May 21 2022

/00Z TAFS/
VFR conditions are expected across all area sites for the next few
hours. Then, a line of thunderstorms associated with a cold front is
forecast to move across the I-35 between 02Z and 06Z. It is a slow
moving system with the potential of producing strong to severe
thunderstorms capable of producing large hail and damaging wind
gusts. It looks like several outflows may linger around and winds are
forecast to stay up overnight. MVFR cigs are also possible overnight
across the I-35 sites and around 10Z or so for KDRT. VFR cigs return
after 16Z for all terminals. Winds are forecast to be out of the
north and northeast around 10 knots or so.

&&

.CLIMATE...

Record High Temperatures for May 21st...

Austin Bergstrom.....97 in 2005
Austin Camp Mabry....99 in 1939
San Antonio Int......98 in 1939
Del Rio.............107 in 1953

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              62  79  66  84 /  60  20  10  70
Austin Bergstrom Intl Airport  63  79  66  84 /  60  20  10  70
New Braunfels Muni Airport     66  80  66  86 /  60  20  10  70
Burnet Muni Airport            59  76  64  81 /  70  20  10  70
Del Rio Intl Airport           68  82  70  85 /  20  30  40  80
Georgetown Muni Airport        62  77  65  82 /  60  20  10  70
Hondo Muni Airport             68  83  69  85 /  60  20  20  80
San Marcos Muni Airport        64  79  66  85 /  60  20  10  70
La Grange - Fayette Regional   67  82  69  88 /  60  40  20  60
San Antonio Intl Airport       66  81  69  84 /  60  20  20  80
Stinson Muni Airport           68  83  69  88 /  60  20  20  80

&&

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

Short-Term...17
Long-Term...Platt
Aviation...29

Hazardous Weather Outlook...UPDATED
National Weather Service Austin/San Antonio TX
1116 PM CDT Sat May 21 2022

TXZ171>173-183>194-202>209-217>225-228-230430-
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-
1116 PM CDT Sat May 21 2022

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

.DAY ONE...Rest of tonight.

Scattered thunderstorms will be possible along and southeast of
the I-35 corridor overnight. Some of this activity could be
severe with large hail and damaging winds the main threat. A
Severe Thunderstorm Watch is in effect for the I-35 corridor and
areas along and south of US-57 through 4 AM Sunday.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Additional strong to possible severe thunderstorms can be expected
on Monday. In addition, locally heavy rainfall is possible Monday
and again on Wednesday.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to submit severe weather reports to the
National Weather Service.

Special Weather Statement
National Weather Service Austin/San Antonio TX
1014 PM CDT Sat May 21 2022

TXZ191-205>208-220400-
Guadalupe TX-Comal TX-Bexar TX-Caldwell TX-Hays TX-
1014 PM CDT Sat May 21 2022

...A strong thunderstorm will impact portions of west central
Caldwell, southern Hays, central Guadalupe, north central Bexar and
Comal Counties through 1100 PM CDT...

At 1014 PM CDT, Doppler radar was tracking a strong thunderstorm near
Canyon Lake Dam, moving southeast at 25 mph.

HAZARD...Wind gusts up to 50 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
New Braunfels, San Marcos, Schertz, Kyle, Seguin, Cibolo, Selma,
Wimberley, Canyon Lake Dam, Canyon Lake, Bulverde, Garden Ridge,
McQueeney, Martindale, Marion, Santa Clara, Staples, Geronimo, Zorn
and Smithson Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

A Severe Thunderstorm Watch remains in effect until 100 AM CDT for
south central Texas.

&&

LAT...LON 2953 9795 2958 9831 2967 9845 2999 9822
      2993 9773
TIME...MOT...LOC 0314Z 294DEG 20KT 2983 9823

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH

BF

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1015 PM CDT SAT MAY 21 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0830 PM     HAIL             HONDO                   29.35N 99.14W
05/21/2022  E1.50 INCH       MEDINA             TX   PUBLIC

            SOCIAL MEDIA REPORT WITH PICTURE.

&&

29

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1040 PM CDT SAT MAY 21 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1035 PM     HAIL             5 WNW NEW BRAUNFELS     29.73N 98.20W
05/21/2022  E0.50 INCH       COMAL              TX   NWS EMPLOYEE

&&

29

Special Weather Statement
National Weather Service Austin/San Antonio TX
1046 PM CDT Sat May 21 2022

TXZ217-218-228-220430-
Maverick TX-Dimmit TX-Zavala TX-
1046 PM CDT Sat May 21 2022

...A strong thunderstorm will impact portions of east central
Maverick, northwestern Dimmit and southwestern Zavala Counties
through 1130 PM CDT...

At 1046 PM CDT, Doppler radar was tracking a strong thunderstorm near
Winter Haven, or near Crystal City, moving south at 10 mph.

HAZARD...Wind gusts up to 50 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Crystal City, Carrizo Springs, Asherton, Las Colonias, Winter Haven,
Chula Vista-River Spur, Cometa, Carrizo Hill and Farias Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 2877 10006 2871 9972 2836 9974 2845 10023
TIME...MOT...LOC 0346Z 010DEG 10KT 2867 9992

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH

BF

Special Weather Statement
National Weather Service Austin/San Antonio TX
1119 PM CDT Sat May 21 2022

TXZ219-220-220500-
Frio TX-Atascosa TX-
1119 PM CDT Sat May 21 2022

...A strong thunderstorm will impact portions of southeastern Frio
and southwestern Atascosa Counties through MIDNIGHT CDT...

At 1119 PM CDT, Doppler radar was tracking a strong thunderstorm 9
miles southwest of Goldfinch, or 13 miles southeast of Pearsall,
moving southeast at 30 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Goldfinch and Hindes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

A Severe Thunderstorm Watch remains in effect until 400 AM CDT for
south central Texas.

&&

LAT...LON 2865 9880 2865 9908 2877 9911 2891 9891
      2869 9864 2863 9875 2864 9880
TIME...MOT...LOC 0419Z 311DEG 27KT 2874 9895

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

PLATT

Special Weather Statement
National Weather Service Austin/San Antonio TX
1130 PM CDT Sat May 21 2022

TXZ219-220-220515-
Frio TX-Atascosa TX-
1130 PM CDT Sat May 21 2022

...A strong thunderstorm will impact portions of east central Frio
and southwestern Atascosa Counties through 1215 AM CDT...

At 1130 PM CDT, Doppler radar was tracking a strong thunderstorm over
Charlotte, moving southeast at 20 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Pleasanton, Jourdanton, Poteet, Charlotte, Coughran, Dobrowolski,
Amphion and Davis.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

A Severe Thunderstorm Watch remains in effect until 400 AM CDT for
south central Texas.

&&

LAT...LON 2891 9890 2907 9870 2899 9835 2869 9864
TIME...MOT...LOC 0430Z 311DEG 19KT 2888 9866

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

PLATT