Alert archive / Texas / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 22, NWS Houston/Galveston, TX

March 23, 20214 counties in Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Mar 23, 2021, 1:55 AM CDT for 4 counties in Texas. It was in force for 35 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
Mar 23, 2021, 1:55 AM CDT (06:55 UTC)
Expired
Mar 23, 2021, 2:30 AM CDT
In force
35 min
Issued by
NWS Houston/Galveston, TX
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Polk County, TX, San Jacinto County, TX, Trinity County, TX, Walker County, TX

The radar

The Houston radar (KHGX), 167 km from the middle of the area, began a volume at 06:59 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.

IssuedProductOfficeLasted
Mar 22, 11:10 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 6.9 hours before the alert went out and 222 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 2021-03-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 82 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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 2021-03-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 183 square meters per square second.1939587897Sfc1 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
82 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
715 m above ground
0-6 km bulk shear
74 kt
0-1 km storm-relative helicity
183 m²/s²
0-3 km storm-relative helicity
405 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

841 
WUUS54 KHGX 230655
SVRHGX
TXC373-407-455-471-230730-
/O.NEW.KHGX.SV.W.0022.210323T0655Z-210323T0730Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Houston/Galveston TX
155 AM CDT Tue Mar 23 2021

The National Weather Service in League City has issued a

* Severe Thunderstorm Warning for...
  Trinity County in southeastern Texas...
  Northwestern San Jacinto County in southeastern Texas...
  Northwestern Polk County in southeastern Texas...
  Northeastern Walker County in southeastern Texas...

* Until 230 AM CDT.

* At 155 AM CDT, a severe thunderstorm was located near Trinity, or
  17 miles north of Huntsville, moving east at 50 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Trinity, Groveton, Riverside and Sebastopol. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3088 9489 3077 9560 3085 9561 3095 9553
      3100 9552 3110 9537 3124 9505
TIME...MOT...LOC 0655Z 253DEG 42KT 3095 9547 

HAIL...0.75IN
WIND...60MPH
 
$$
2 follow-up statements
235 
WWUS54 KHGX 230711
SVSHGX

Severe Weather Statement
National Weather Service Houston/Galveston TX
211 AM CDT Tue Mar 23 2021

TXC373-407-455-471-230730-
/O.CON.KHGX.SV.W.0022.000000T0000Z-210323T0730Z/
Trinity TX-San Jacinto TX-Polk TX-Walker TX-
211 AM CDT Tue Mar 23 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 230 AM CDT
FOR SOUTHERN TRINITY...NORTHWESTERN SAN JACINTO...NORTHWESTERN POLK
AND NORTHEASTERN WALKER COUNTIES...

At 211 AM CDT, a severe thunderstorm was located over Sebastopol, or
24 miles northeast of Huntsville, moving east at 40 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Trinity, Groveton, Riverside and Sebastopol. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3080 9543 3096 9536 3104 9531 3117 9502
      3088 9489
TIME...MOT...LOC 0711Z 261DEG 34KT 3094 9525 

HAIL...0.75IN
WIND...60MPH
 
$$
354 
WWUS54 KHGX 230721
SVSHGX

Severe Weather Statement
National Weather Service Houston/Galveston TX
221 AM CDT Tue Mar 23 2021

TXC407-471-230731-
/O.CAN.KHGX.SV.W.0022.000000T0000Z-210323T0730Z/
San Jacinto TX-Walker TX-
221 AM CDT Tue Mar 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SAN JACINTO AND
NORTHEASTERN WALKER COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 400 AM CDT for
southeastern Texas.

LAT...LON 3088 9489 3083 9522 3084 9523 3097 9520
      3104 9518 3109 9498
TIME...MOT...LOC 0721Z 253DEG 42KT 3097 9512 

$$

TXC373-455-230730-
/O.CON.KHGX.SV.W.0022.000000T0000Z-210323T0730Z/
Trinity TX-Polk TX-
221 AM CDT Tue Mar 23 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 230 AM CDT
FOR SOUTHEASTERN TRINITY AND NORTHWESTERN POLK COUNTIES...

At 221 AM CDT, a severe thunderstorm was located near Groveton, or 19
miles southwest of Apple Springs, moving east at 50 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Groveton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3088 9489 3083 9522 3084 9523 3097 9520
      3104 9518 3109 9498
TIME...MOT...LOC 0721Z 253DEG 42KT 3097 9512 

HAIL...1.00IN
WIND...60MPH
 
$$

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 22, 11:18 PM CDTSpecial Weather StatementHGXBrazos, Burleson, Madison87 min
Mar 22, 11:57 PM CDTSevere Thunderstorm WarningHGXBrazos, Burleson48 min
Mar 23, 12:30 AM CDTSmall Craft AdvisoryHGX4 hr
Mar 23, 12:43 AM CDTSevere Thunderstorm WarningHGXBrazos, Grimes, Madison47 min
Mar 23, 1:16 AM CDTSpecial Weather StatementHGXBurleson, Grimes, Washington44 min
Mar 23, 1:19 AM CDTSevere Thunderstorm WarningHGXGrimes, Houston, Madison, Trinity, Walker41 min
Mar 23, 2:29 AM CDTSevere Thunderstorm WarningHGXPolk, Trinity31 min
Mar 23, 3:16 AM CDTSevere Thunderstorm WarningHGXColorado26 min
Mar 23, 3:20 AM CDTSpecial Weather StatementHGXAustin40 min
Mar 23, 3:44 AM CDTSpecial Weather StatementHGXColorado31 min
Mar 23, 4:06 AM CDTSpecial Weather StatementHGXFort Bend, Waller, Wharton54 min
Mar 23, 4:28 AM CDTSpecial Weather StatementHGXPolk62 min
Mar 23, 5:50 AM CDTSpecial Weather StatementHGXBrazoria55 min
Mar 23, 6:02 AM CDTSpecial Weather StatementHGXGalveston43 min

Nearby

Severe Thunderstorm Warnings in Texas, 2021Every severe thunderstorm warning 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.