Alert archive / Texas / Areal Flood Advisories in 2021

Areal Flood Advisory 44, NWS Austin/San Antonio, TX

May 15, 20214 counties in Texas

NWS Austin/San Antonio, TX issued this areal flood advisory at May 15, 2021, 5:35 PM CDT for 4 counties in Texas. It was in force for 115 min.

The area

The counties it named.

The facts

Issued: May 15, 2021, 5:35 PM CDT (22:35 UTC)
Expired: May 15, 2021, 7:30 PM CDT
In force: 115 min
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon

Counties Frio County, TX, Medina County, TX, Uvalde County, TX, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 84 km from the middle of the area, began a volume at 22:38 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Del Rio, TX (KDRT), launched 12:00Z, 10.6 hours before the alert went out and 139 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 660 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 602 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 178 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Austin/San Antonio, TX wrote its last area forecast discussion before this areal flood advisory went out at May 15, 4:20 PM CDT, 1 hour 15 minutes earlier.

Area forecast discussion, May 15, 4:20 PM CDT, 1 hour 15 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Hazardous weather outlook, May 15, 4:42 AM CDT, 12 hours 53 minutes before

Hazardous Weather Outlook
National Weather Service Austin/San Antonio TX
442 AM CDT Sat May 15 2021

TXZ171>173-183>194-202>209-217>225-228-160945-
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-
442 AM CDT Sat May 15 2021

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

.DAY ONE...Today And Tonight.

There is a chance for strong to severe thunderstorms today for
areas generally along and west of a Llano to Cuero line. The
chance for severe weather increases slightly for areas along and
west of a Kerrville to Castroville to Cotulla line. Hail and high
winds are the main severe weather concerns. In addition, locally
heavy rainfall is possible for areas west of a Llano to Cuero
line.

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

There is a low chance for strong to severe thunderstorms on
Sunday across most of south central Texas. Hail and high winds
are the main severe weather concerns. Some locally heavy downpours
are also possible.

For Monday through Wednesday, we could see several rounds of
showers and thunderstorms across south central Texas. Strong to
severe thunderstorms along with locally heavy rainfall are
possible across most of the region.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

In the hours before

Local storm report, May 15, 2:57 PM CDT, 2 hours 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
257 PM CDT SAT MAY 15 2021

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

0253 PM     FLASH FLOOD      2 NNE UVALDE            29.24N 99.77W
05/15/2021                   UVALDE             TX   LAW ENFORCEMENT

            LAW ENFORCEMENT REPORTED CITY STREETS
            CLOSURES DUE TO FLASH FLOODING INCLUDING FM
            3447 AND 2369.

&&

OB

Local storm report, May 15, 3:02 PM CDT, 2 hours 33 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
302 PM CDT SAT MAY 15 2021

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

0258 PM     FLASH FLOOD      8 S SABINAL             29.20N 99.46W
05/15/2021                   UVALDE             TX   LAW ENFORCEMENT

            LAW ENFORCEMENT REPORTED FLASH FLOODING
            OCCURRING WITH STREET CLOSURES ALONG 187
            SOUTH OF SABINAL AND COYOTE RANCH RD. RAIN
            GAUGE NEARBY THIS LOCATION HAS MEASURED 6.59
            INCHES LAST 4 HOURS.

&&

OB

Special weather statement, May 15, 3:31 PM CDT, 2 hours 4 minutes before

Special Weather Statement
National Weather Service Austin/San Antonio TX
331 PM CDT Sat May 15 2021

TXZ220-152115-
Atascosa TX-
331 PM CDT Sat May 15 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN ATASCOSA COUNTY
UNTIL 415 PM CDT...

At 331 PM CDT, Doppler radar was tracking a strong thunderstorm near
Christine, moving northeast at 15 mph.

Penny size hail will be possible with this storm.

Locations impacted include...
Pleasanton, Jourdanton and Christine.

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.

&&

LAT...LON 2865 9862 2881 9872 2901 9849 2877 9830
TIME...MOT...LOC 2031Z 240DEG 12KT 2877 9860

RUNYEN

Special weather statement, May 15, 4:08 PM CDT, 1 hour 27 minutes before

Special Weather Statement
National Weather Service Austin/San Antonio TX
408 PM CDT Sat May 15 2021

TXZ220-152200-
Atascosa TX-
408 PM CDT Sat May 15 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN ATASCOSA COUNTY
UNTIL 500 PM CDT...

At 407 PM CDT, Doppler radar was tracking a strong thunderstorm near
Christine, moving east at 15 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Christine, Campbellton, Peggy and Fashing.

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.

&&

LAT...LON 2864 9834 2864 9853 2865 9856 2883 9854
      2885 9815 2879 9810 2861 9833
TIME...MOT...LOC 2107Z 285DEG 14KT 2872 9844

RUNYEN

The office that day

Everything else NWS Austin/San Antonio, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 15, 12:20 PM CDT	Areal Flood Advisory	EWX	Uvalde	3 hr
May 15, 12:55 PM CDT	Flash Flood Warning Considerable damage threat	EWX	Uvalde	4 hr
May 15, 1:30 PM CDT	Flash Flood Warning Considerable damage threat	EWX	Frio, Medina, Uvalde	4 hr
May 15, 3:24 PM CDT	Areal Flood Advisory	EWX	Frio, Zavala	2 hr
May 15, 3:31 PM CDT	Special Weather Statement	EWX	Atascosa	44 min
May 15, 3:51 PM CDT	Areal Flood Advisory	EWX	Atascosa	3 hr
May 15, 4:08 PM CDT	Special Weather Statement	EWX	Atascosa	52 min
May 15, 4:17 PM CDT	Areal Flood Advisory	EWX	Atascosa	3 hr
May 15, 5:26 PM CDT	Areal Flood Advisory	EWX	Uvalde	94 min

Nearby

Areal Flood Advisories in Texas, 2021 Every areal flood advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.