Alert archive / Texas / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 6, NWS Houston/Galveston, TX

February 21, 2003Polk County, San Jacinto County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Feb 21, 2003, 6:51 AM CST for Polk County, San Jacinto County, Texas. It was in force for 39 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: Feb 21, 2003, 6:51 AM CST (12:51 UTC)
Expired: Feb 21, 2003, 7:30 AM CST
In force: 39 min
Issued by: NWS Houston/Galveston, TX
Area: Counties, with a storm outline in the text

Counties Polk County, TX, San Jacinto County, TX

The radar

The Houston radar (KHGX), 135 km from the middle of the area, began a volume at 12:53 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Feb 21, 4:25 AM CST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 0.9 hours before the alert went out and 184 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: 543 J/kg
Mixed-layer CIN: -114 J/kg
Mixed-layer LCL: 433 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 253 m²/s²
0-3 km storm-relative helicity: 274 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.2

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 Feb 21, 6:32 AM CST, 19 minutes earlier.

Area forecast discussion, Feb 21, 6:32 AM CST, 19 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, Feb 20, 4:28 PM CST, 14 hours 23 minutes before

TXZ163-164-176>179-195>200-210>214-226-227-235>238-211300-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
428 PM CST THU FEB 20 2003

...THREAT FOR HEAVY RAINFALL AND SEVERE STORMS ACROSS SOUTHEAST
TEXAS THROUGH FRIDAY...
...FLOOD WATCH IN EFFECT THROUGH FRIDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST TEXAS.

.DAY ONE...TONIGHT AND FRIDAY.

A STATIONARY FRONT FROM NEAR COLUMBUS TO BEAUMONT WILL MEANDER
SLOWLY NORTH OVERNIGHT. DEEP MOISTURE WILL STREAM INLAND AND WILL
OVER RUN THIS BOUNDARY HELPING TO FOCUS HEAVY RAINS.  A SERIES OF
UPPER LEVEL DISTURBANCES WILL MOVE OVER THE REGION BRINGING BANDS OF
PRECIPITATION. LOCALLY HEAVY RAINFALL WILL BE LIKELY WITH SOME OF THE
STORMS. RAINFALL AMOUNTS WILL AVERAGE 1 TO 2 INCHES WITH ISOLATED
TOTALS OF 7 TO 9 INCHES BY THE TIME THE EVENT COMES TO AN END FRIDAY
EVENING. GIVEN THE HEAVY RAINS THAT HAVE FALLEN A FLASH FLOOD
WATCH WILL BE IN EFFECT THROUGH FRIDAY.

IN ADDITION...THE ATMOSPHERIC WIND PROFILE WILL FAVOR THE POSSIBILITY
OF A FEW STORMS BECOMING SEVERE TONIGHT AND FRIDAY.  LARGE HAIL AND
ISOLATED TORNADOES WILL BE THE PRIMARY SEVERE WEATHER THREATS...WITH
DAMAGING WINDS ALSO POSSIBLE.

REMEMBER...A FLOOD WATCH MEANS RAPIDLY RISING WATER OR FLOODING IS
POSSIBLE WITHIN THE WATCH AREA. CHECK OVER YOUR PREPAREDNESS
REQUIREMENTS...KEEP INFORMED...AND BE READY FOR QUICK ACTION IF
FLOODING IS OBSERVED OR IF A WARNING IS ISSUED.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

SATURDAY THROUGH WEDNESDAY...NO HAZARDOUS WEATHER EXPECTED AT THIS
TIME...BUT RIVER FLOODING PROBLEMS COULD BE ONGOING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT AND SHOULD BE EXPECTED
FRIDAY.

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 20, 6:10 PM CST	Flash Flood Warning	HGX	Brazos, Burleson, Grimes, Houston, Madison, Walker	4 hr
Feb 20, 8:21 PM CST	Flash Flood Warning	HGX	Washington	114 min
Feb 21, 4:53 AM CST	Severe Thunderstorm Warning	HGX	Jackson	22 min
Feb 21, 5:15 AM CST	Severe Thunderstorm Warning	HGX	Jackson, Wharton	45 min
Feb 21, 12:20 PM CST	Severe Thunderstorm Warning	HGX	Brazoria, Galveston	40 min
Feb 21, 12:46 PM CST	Special Marine Warning	HGX		59 min
Feb 21, 1:32 PM CST	Severe Thunderstorm Warning	HGX	Fort Bend	43 min
Feb 21, 1:45 PM CST	Severe Thunderstorm Warning	HGX	Harris	60 min
Feb 21, 2:20 PM CST	Severe Thunderstorm Warning	HGX	Montgomery	55 min
Feb 21, 2:54 PM CST	Severe Thunderstorm Warning	HGX	Liberty	66 min
Feb 21, 3:15 PM CST	Severe Thunderstorm Warning	HGX	Polk	45 min
Feb 21, 4:16 PM CST	Severe Thunderstorm Warning	HGX	Liberty	44 min

Nearby

Severe Thunderstorm Warnings in Texas, 2003 Every severe thunderstorm warning in 2003

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.