Special Weather Statement, NWS Austin/San Antonio, TX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
231 PM CDT Thu May 28 2020

.UPDATE...
The Storm Prediction Center has issued a Severe Thunderstorm watch
for generally areas along and west of HWY 281, in addition to Hays,
Guadalupe, and Wilson Counties. This includes the San Antonio and Del
Rio metro areas. The watch runs through 10 pm tonight and highlights
the threat for hail up to 2 inches and 70 mph winds.

&&

.PREV DISCUSSION... /ISSUED 211 PM CDT Thu May 28 2020/

SHORT TERM (Tonight through Friday Night)...
After yesterday's severe weather event that left large swaths of
quarter sized hail or greater, several hail reports between 2-2.75
inches, and gusty winds in several spots it looks like there will be
one more round of strong to severe storms this evening before
quieter weather prevails tomorrow into the weekend.

With the pesky upper level low to the northeast of Texas, over the
Oklahoma/Arkansas border, it leaves South Central Texas in a
northwest flow pattern. Despite several rounds of storms over the
last few days southeasterly winds at the surface continue to allow
for plentiful moisture return between the rounds. Couple this with
lift associated with daytime heating and a boundary moving in from
the north, instability of between 2000-3000 j/KG, and just enough
shear to help the storms maintain the strength and you get the
recipe for the strong to severe storms today. Convective initiation
is already ongoing across San Angelo's area from San Angelo south to
Junction. This is earlier than really any of the convective allowing
models showed CI ongoing today. Several severe thunderstorm
warnings have already been issued for this activity.

The spread of the morning high resolution models really resolved
into 3 camps: 1) some (like the Texas Tech WRF) developed storms
into a complex that could dive to the southeast and impact areas
from San Antonio to Austin, 2) others (like many members of the 12z
SPC HREF) developed storms to the north of our area and took them
generally south through the Edwards Plateau along and west of HWY
281, 3) Lastly the HRRR has trended drier for most of its runs since
12z with only isolated storms through the evening. Just using
current radar trends with the activity over SJT's CWA the 2nd
scenario seems most likely. Outflows are driving the storms more to
the south and are kicking off additional storms. The 1st scenario
does remain feasible as the storms could come together developing a
cold pool, and drive to the southeast. The 12z/16z SPC updates take
this scenario into account as they extended the slight risk eastward
from just across the Rio Grande Plains to a Kerrville to San Antonio
to Cuero line. Trends will have to be monitored through the
afternoon, but still think that the best chances for storms will be
along and west of the HWY 281 corridor through the evening. An MCD
just issued by SPC highlights the risk of rapid updraft
intensification due to the steep lapse rates which would mainly lead
to a hail threat in the short term. If/when these storms grow
upscale and develop that cold pool and become a complex of storms
damaging thunderstorm winds would become the main concern.

All of this is occurring within the northwest flow aloft along the
leading edge of a weak front. Models show a distinct northerly wind
shift with drier and slightly cooler air working south later this
evening into the overnight behind the storms. This along with the
upper level ridge building in from the west as the upper low exits
tomorrow will squash any further rain chances and lead to a drying
trend for Friday into much of next week. With the drier air in place
afternoon highs should only climb into the mid to upper 80s to lower
90s for Friday and Saturday. This is very close to normal for this
time of the year. Looking back at the months of April and May our
County Warning Area was under a Marginal, Slight, or Enhanced risk
of severe storms from SPC over 50 percent of the days. As I said in
the morning update AFD I think most folks in South Central Texas
will welcome the quieter weather pattern and seasonable temperatures
through the middle of next week. Whether it has been the busy
emergency managers and local TV/private/NWS meteorologists or those
who have been impacted by the hail/wind/tornadoes over the last few
weeks it will give us all time to take a breath and enjoy the quiet
weather.

LONG TERM (Saturday through Thursday)...
Fairly quiet weather pattern will be in place to start the long term
with an omega block setting up over the CONUS. An upper level ridge
will build over the middle of the US and a large upper level trough
over the Pacific and another over the Northeast US. The only feature
preventing a true omega block pattern setting up will be an inverted
trough that global models keep over Mexico and southern TX late this
weekend. The feature will slowly advect northward and push some
energy up into South-Central TX by early next week. Only have slight
chances for showers and storms in the forecast for Monday into
Tuesday for this.

Apart from this, a benign pattern will remain in place with high
temperatures running close to climatological normals and little to
no chance for rain. A much needed break from the active weather the
region has had over the last couple of weeks.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              68  87  65  87  66 /  20   0   0   0   0
Austin Bergstrom Intl Airport  67  86  64  87  64 /  20   0   0   0   0
New Braunfels Muni Airport     68  87  64  88  64 /  30   0   0   0   0
Burnet Muni Airport            64  85  62  86  63 /  10   0   0   0   0
Del Rio Intl Airport           70  92  67  93  68 /  40  -    0   0   0
Georgetown Muni Airport        65  86  62  87  64 /  10   0   0   0   0
Hondo Muni Airport             68  90  64  92  66 /  30  -    0   0   0
San Marcos Muni Airport        67  86  64  88  64 /  20   0   0   0   0
La Grange - Fayette Regional   69  86  65  88  65 /  20  10   0   0   0
San Antonio Intl Airport       69  88  66  90  67 /  30   0   0   0   0
Stinson Muni Airport           70  89  67  90  68 /  30  -    0   0   0

&&

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

Short-Term/Aviation...Treadway
Long-Term...EWilliams
Decision Support...BMW

Hazardous Weather Outlook
National Weather Service Austin/San Antonio TX
312 PM CDT Thu May 28 2020

TXZ171>173-183>194-202>209-217>225-228-292015-
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-
312 PM CDT Thu May 28 2020

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

.DAY ONE...This Afternoon And Tonight.

Scattered strong to severe thunderstorms are possible this
afternoon and evening along and west of a Fredericksburg to New
Braunfels to Cuero line. Main threats will include large hail and
damaging wind gusts. Heavy rainfall, especially from storms that
train over the same area, could cause localized flooding issues. A
Severe Thunderstorm Watch is in effect for these areas.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather expected for the extended forecast period at
this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and evening.

Special Weather Statement
National Weather Service Austin/San Antonio TX
518 PM CDT Thu May 28 2020

TXZ183-282245-
Val Verde TX-
518 PM CDT Thu May 28 2020

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL VAL VERDE COUNTY UNTIL
545 PM CDT...

At 518 PM CDT, Doppler radar was tracking a strong thunderstorm near
Shumla, or 9 miles northeast of Langtry, moving south at 35 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Comstock, Shumla, Seminole Canyon State Park, Pafford Crossing, Pecos
River Boat Ramp, Bakers Crossing, Devils River State Nat Area Del
Norte and Devils River State Nat Area Big Satan.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
south central Texas.

LAT...LON 2995 10161 3008 10108 3000 10086 2970 10077
      2959 10125 2962 10125 2963 10127 2959 10128
      2958 10131 2965 10130 2966 10135 2965 10136
      2970 10137 2975 10142 2977 10140 2975 10144
      2979 10146 2977 10150
TIME...MOT...LOC 2218Z 342DEG 32KT 2986 10142

02

Special Weather Statement
National Weather Service Austin/San Antonio TX
527 PM CDT Thu May 28 2020

TXZ202-217-282315-
Maverick TX-Kinney TX-
527 PM CDT Thu May 28 2020

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN KINNEY AND
NORTHWESTERN MAVERICK COUNTIES UNTIL 615 PM CDT...

At 527 PM CDT, Doppler radar was tracking a strong thunderstorm 10
miles southwest of Spofford, moving southeast at 10 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Spofford, Quemado, Normandy, Darling, Paloma and Laughlin AFB Aux
Field.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 1000 PM CDT for
south central Texas.

LAT...LON 2888 10060 2889 10059 2891 10062 2890 10063
      2892 10063 2894 10065 2900 10065 2909 10067
      2911 10069 2912 10072 2917 10078 2920 10077
      2922 10078 2916 10030 2887 10039
TIME...MOT...LOC 2227Z 322DEG 7KT 2911 10057

BMW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
534 PM CDT THU MAY 28 2020

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

0504 PM     HAIL             11 W KICKAPOO CAVERN ST 29.61N 100.64W
05/28/2020  E1.50 INCH       KINNEY             TX   STORM CHASER

&&

PAY

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
538 PM CDT THU MAY 28 2020

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

0537 PM     HAIL             3 ESE GREY FOREST       29.60N 98.63W
05/28/2020  E0.88 INCH       BEXAR              TX   PUBLIC

&&

PAY

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
552 PM CDT THU MAY 28 2020

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

0546 PM     TSTM WND GST     2 WNW DEL RIO           29.37N 100.93W
05/28/2020  E52 MPH          VAL VERDE          TX   ASOS

&&

PAY

Special Weather Statement
National Weather Service Austin/San Antonio TX
555 PM CDT Thu May 28 2020

TXZ183-202-282345-
Kinney TX-Val Verde TX-
555 PM CDT Thu May 28 2020

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN KINNEY AND SOUTHEASTERN
VAL VERDE COUNTIES UNTIL 645 PM CDT...

At 554 PM CDT, Doppler radar was tracking a strong thunderstorm near
Amanda, or 12 miles northeast of Del Rio, moving south at 30 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.

Locations impacted include...
Del Rio, Val Verde Park, Standart, Amanda, Cienegas Terrace, Laughlin
AFB, Escondido Estates and Lake Ridge Ranch.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
south central Texas.

LAT...LON 2962 10082 2959 10055 2910 10050 2912 10071
      2917 10078 2920 10077 2926 10081 2928 10087
      2931 10089 2935 10096
TIME...MOT...LOC 2254Z 002DEG 26KT 2946 10071

BMW