Alert archive / Texas / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 21, NWS Houston/Galveston, TX

April 26, 2011Montgomery County, San Jacinto County, Walker County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Apr 26, 2011, 12:56 AM CDT for Montgomery County, San Jacinto County, Walker County, Texas. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 26, 2011, 12:56 AM CDT (05:56 UTC)
Expired
Apr 26, 2011, 1:45 AM CDT
In force
49 min
Issued by
NWS Houston/Galveston, TX
Area
Storm-based polygon

Counties Montgomery County, TX, San Jacinto County, TX, Walker County, TX

The radar

The Houston radar (KHGX), 123 km from the middle of the area, began a volume at 05:57 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

Lake Charles Mun, LA (KLCH), launched 00:00Z, 5.9 hours before the alert went out and 211 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-pSkew-T log-p diagram, Lake Charles Mun, LA at 00:00Z on 2011-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2759 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 00:00Z on 2011-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
2759 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
581 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
133 m²/s²
Significant tornado parameter
1.5
Supercell composite
8.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

632 
WUUS54 KHGX 260556
SVRHGX
TXC339-407-471-260645-
/O.NEW.KHGX.SV.W.0021.110426T0556Z-110426T0645Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1256 AM CDT TUE APR 26 2011

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST TEXAS...
  WESTERN SAN JACINTO COUNTY IN SOUTHEAST TEXAS...
  SOUTHEASTERN WALKER COUNTY IN SOUTHEAST TEXAS...

* UNTIL 145 AM CDT

* AT 1252 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  NEW WAVERLY...OR 9 MILES NORTH OF WILLIS...AND MOVING EAST AT 25
  MPH.

* LOCATIONS IN THE SEVERE THUNDERSTORM WARNING INCLUDE BUT ARE NOT   
LIMITED TO HUNTSVILLE STATE PARK AND NEW WAVERLY.

PLEASE REPORT SEVERE WEATHER TO THE COUNTY SHERIFF...LOCAL POLICE...
OR DEPARTMENT OF PUBLIC SAFETY AND ASK THEM TO RELAY YOUR REPORT TO
THE NATIONAL WEATHER SERVICE.

LAT...LON 3071 9517 3033 9516 3039 9539 3052 9565
      3069 9550
TIME...MOT...LOC 0556Z 292DEG 20KT 3055 9546

$$
1 follow-up statement
624 
WWUS54 KHGX 260629
SVSHGX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
129 AM CDT TUE APR 26 2011

TXC471-260639-
/O.CAN.KHGX.SV.W.0021.000000T0000Z-110426T0645Z/
WALKER TX-
129 AM CDT TUE APR 26 2011

...THE SEVERE THUNDERSTORM WARNING FOR WALKER COUNTY IS CANCELLED...

LAT...LON 3039 9539 3047 9555 3052 9543 3052 9537
      3057 9536 3071 9517 3033 9516
TIME...MOT...LOC 0629Z 292DEG 20KT 3048 9526

$$

TXC339-407-260645-
/O.CON.KHGX.SV.W.0021.000000T0000Z-110426T0645Z/
SAN JACINTO TX-MONTGOMERY TX-
129 AM CDT TUE APR 26 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 AM CDT
FOR MONTGOMERY AND SAN JACINTO COUNTIES...

AT 125 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED OVER SAN JACINTO COUNTY...OR 12 MILES EAST OF WILLIS...MOVING
EAST AT 25 MPH.

THE SEVERE THUNDERSTORM WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS
OF THE INDICATED COUNTY.

LAT...LON 3039 9539 3047 9555 3052 9543 3052 9537
      3057 9536 3071 9517 3033 9516
TIME...MOT...LOC 0629Z 292DEG 20KT 3048 9526

$$

KP

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 25, 7:46 PM CDTTornado WarningHGXHouston44 min
Apr 25, 8:27 PM CDTTornado WarningHGXHouston48 min
Apr 25, 9:08 PM CDTSevere Thunderstorm WarningHGXHouston37 min
Apr 25, 9:11 PM CDTTornado WarningHGXHouston, Trinity64 min
Apr 25, 9:18 PM CDTTornado WarningHGXHouston, Trinity42 min
Apr 25, 10:11 PM CDTSevere Thunderstorm WarningHGXPolk, Trinity49 min
Apr 25, 10:30 PM CDTSevere Thunderstorm WarningHGXHouston45 min
Apr 25, 11:00 PM CDTSpecial Weather StatementHGXHouston, Madison, Trinity90 min
Apr 25, 11:09 PM CDTSevere Thunderstorm WarningHGXHouston, Madison, Polk, San Jacinto, Trinity, Walker51 min
Apr 25, 11:16 PM CDTSevere Thunderstorm WarningHGXPolk, Trinity44 min
Apr 25, 11:33 PM CDTTornado WarningHGXPolk, San Jacinto, Trinity27 min
Apr 25, 11:56 PM CDTTornado WarningHGXPolk, Trinity64 min
Apr 25, 11:59 PM CDTSevere Thunderstorm WarningHGXGrimes, Polk, San Jacinto, Trinity, Walker61 min
Apr 26, 1:00 AM CDTSevere Thunderstorm WarningHGXLiberty, Polk, San Jacinto60 min
Apr 26, 1:43 AM CDTSevere Thunderstorm WarningHGXLiberty, Montgomery, Polk, San Jacinto47 min
Apr 26, 2:54 AM CDTSpecial Weather StatementHGXLiberty66 min
Apr 26, 10:52 AM CDTSmall Craft AdvisoryHGX22 hr
Apr 26, 4:23 PM CDTSevere Thunderstorm WarningHGXHouston52 min
Apr 26, 5:11 PM CDTSevere Thunderstorm WarningHGXHouston49 min
Apr 26, 5:27 PM CDTSpecial Weather StatementHGXMadison33 min
Apr 26, 5:58 PM CDTSpecial Weather StatementHGXHouston32 min

Nearby

Severe Thunderstorm Warnings in Texas, 2011Every severe thunderstorm warning in 2011

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.