Alert archive / Texas / Severe Thunderstorm Warnings in 2016

Severe Thunderstorm Warning 25, NWS Houston/Galveston, TX

April 21, 2016Trinity County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Apr 21, 2016, 9:23 AM CDT for Trinity County, Texas. It was in force for 20 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 21, 2016, 9:23 AM CDT (14:23 UTC)
Expired: Apr 21, 2016, 9:43 AM CDT
In force: 20 min
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Trinity County, TX

The radar

The Houston radar (KHGX), 180 km from the middle of the area, began a volume at 14:23 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

Shreveport, LA (KBAD), launched 12:00Z, 2.4 hours before the alert went out and 203 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: 107 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 588 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 72 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Houston/Galveston, TX wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 21, 7:15 AM CDT, 2 hours 8 minutes earlier.

Area forecast discussion, Apr 21, 7:15 AM CDT, 2 hours 8 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, Apr 21, 4:06 AM CDT, 5 hours 17 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>

In the hours before

Special weather statement, Apr 21, 8:16 AM CDT, 1 hour 7 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
816 AM CDT THU APR 21 2016

TXZ163-164-176>179-195>199-210>213-226-227-211415-
MADISON TX-TRINITY TX-BURLESON TX-SAN JACINTO TX-WALKER TX-WALLER TX-
POLK TX-WASHINGTON TX-HARRIS TX-WHARTON TX-FORT BEND TX-
MONTGOMERY TX-BRAZOS TX-GRIMES TX-AUSTIN TX-COLORADO TX-HOUSTON TX-
816 AM CDT THU APR 21 2016

...LINE OF STORMS MOVING INTO THE AREA...

AT 814 AM CDT...DOPPLER RADAR WAS TRACKING STRONG THUNDERSTORMS ALONG
A LINE EXTENDING FROM NEAR REESE TO 6 MILES SOUTH OF CROCKETT TO 8
MILES SOUTHEAST OF MADISONVILLE TO NEAR MILLICAN TO NEAR PALMETO.
MOVEMENT WAS SOUTHEAST AT 35 MPH.

WINDS IN EXCESS OF 35 MPH WILL BE POSSIBLE WITH THESE STORMS. BRIEF
HEAVY RAIN WITH 1/2 TO 3/4 INCH ACCUMULATIONS CAN BE EXPECTED ALONG
THE LEADING EDGE OF THE LINE.

LOCATIONS IMPACTED INCLUDE...
CONROE...HUNTSVILLE...BRENHAM...TOMBALL...NAVASOTA...CROCKETT...SEALY...
HEMPSTEAD...WILLIS...PRAIRIE VIEW...BROOKSHIRE...BELLVILLE...COLUMBUS...
EAGLE LAKE...PINEHURST...THE WOODLANDS...APPLE SPRINGS...WASHINGTON...
HOCKLEY AND OAK RIDGE NORTH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS.
LIGHTNING CAN STRIKE 10 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 3158 9517 3147 9510 3133 9490 3128 9488
      3063 9498 3027 9529 2992 9568 2936 9658
      2963 9687 2996 9657 3015 9665 3016 9669
      3014 9677 3015 9677 3051 9618 3086 9580
      3122 9549 3157 9543
TIME...MOT...LOC 1314Z 323DEG 32KT 3205 9534 3122 9549 3086 9580 3051
9619 2961 9765

Special weather statement, Apr 21, 9:11 AM CDT, 12 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
911 AM CDT THU APR 21 2016

TXZ164-177>179-199-200-210>214-226-227-235-237-238-211545-
TRINITY TX-SAN JACINTO TX-WALKER TX-WALLER TX-POLK TX-HARRIS TX-
WHARTON TX-FORT BEND TX-MONTGOMERY TX-GALVESTON TX-AUSTIN TX-
CHAMBERS TX-JACKSON TX-BRAZORIA TX-COLORADO TX-LIBERTY TX-
911 AM CDT THU APR 21 2016

...LINE OF STORMS MOVING INTO THE AREA FROM THE NORTH...

AT 908 AM CDT...DOPPLER RADAR WAS TRACKING STRONG THUNDERSTORMS ALONG
A LINE EXTENDING FROM 6 MILES SOUTHWEST OF POLLOK TO 9 MILES
SOUTHWEST OF POINT BLANK TO 6 MILES SOUTHWEST OF LAKE CONROE DAM TO
NEAR WALLER TO 9 MILES SOUTHEAST OF INDUSTRY TO NEAR FLATONIA.
MOVEMENT WAS SOUTHEAST AT 35 MPH.

HALF INCH HAIL AND WINDS GUSTS BETWEEN 25 AND 40 MPH WILL BE
POSSIBLE WITH THE STRONGER CELLS EMBEDDED IN THE LINE. BRIEF HEAVY
RAIN WITH 1/2 TO 1 INCH ACCUMULATIONS CAN BE EXPECTED ALONG THE
LEADING EDGE OF THE LINE.

LOCATIONS IMPACTED INCLUDE...
PASADENA...PEARLAND...SUGAR LAND...BAYTOWN...MISSOURI CITY...CONROE...DEER
PARK...ROSENBERG...STAFFORD...SOUTH HOUSTON...BELLAIRE...HUMBLE...WEST
UNIVERSITY PLACE...KATY...RICHMOND...EL CAMPO...GALENA PARK...TOMBALL...
JACINTO CITY AND WHARTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS.
LIGHTNING CAN STRIKE 10 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 2933 9656 2963 9687 2973 9678 3008 9589
      3028 9563 3134 9495 3133 9490 3115 9486
      3106 9456 3101 9466 3049 9454 3049 9473
      3011 9460 3011 9444 2993 9454 2973 9480
      2893 9680 2902 9683 2906 9694
TIME...MOT...LOC 1408Z 289DEG 32KT 3139 9494 3068 9536 3029 9564 3009
9590 2988 9640 2965 9703

The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 20, 11:53 PM CDT	Areal Flood Warning	HGX	Austin, Colorado, Fort Bend, Harris, Montgomery, Waller and 1 more	24 hr
Apr 21, 8:16 AM CDT	Special Weather Statement	HGX	Austin, Colorado, Grimes, Houston, Montgomery, San Jacinto and 4 more	59 min
Apr 21, 9:11 AM CDT	Special Weather Statement	HGX	Austin, Colorado, Fort Bend, Harris, Liberty, Montgomery and 4 more	94 min
Apr 21, 9:44 AM CDT	River Flood Warning	HGX	Trinity, Walker	22 days
Apr 21, 10:16 AM CDT	Special Marine Warning	HGX		89 min
Apr 21, 10:43 AM CDT	Special Weather Statement	HGX	Brazoria, Chambers, Fort Bend, Galveston, Wharton	92 min
Apr 21, 11:21 AM CDT	Areal Flood Advisory	HGX	Liberty	114 min
Apr 21, 11:47 AM CDT	Special Marine Warning	HGX		118 min
Apr 21, 12:50 PM CDT	Special Marine Warning	HGX		25 min
Apr 21, 12:54 PM CDT	Special Marine Warning	HGX		51 min
Apr 21, 2:26 PM CDT	Special Marine Warning	HGX		2 hr
Apr 21, 3:19 PM CDT	River Flood Warning	HGX	Chambers, Liberty	28 days

Nearby

Severe Thunderstorm Warnings in Texas, 2016 Every severe thunderstorm warning in 2016

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.