Alert archive / Texas / Tornado Warnings in 2021

Tornado Warning 22, NWS Houston/Galveston, TX

July 12, 2021Montgomery County, Walker County, Texas

NWS Houston/Galveston, TX issued this tornado warning at Jul 12, 2021, 1:21 PM CDT for Montgomery County, Walker County, Texas. It was in force for 12 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
Jul 12, 2021, 1:21 PM CDT (18:21 UTC)
Expired
Jul 12, 2021, 1:33 PM CDT
In force
12 min
Issued by
NWS Houston/Galveston, TX
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Montgomery County, TX, Walker County, TX

The radar

The Houston radar (KHGX), 139 km from the middle of the area, began a volume at 18:21 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 12:00Z, 6.4 hours before the alert went out and 245 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 12:00Z on 2021-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2909 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 12:00Z on 2021-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.1939Sfc1 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
2909 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
749 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

906 
WFUS54 KHGX 121821
TORHGX
TXC339-471-121845-
/O.NEW.KHGX.TO.W.0022.210712T1821Z-210712T1845Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Houston/Galveston TX
121 PM CDT Mon Jul 12 2021

The National Weather Service in League City has issued a

* Tornado Warning for...
  Northwestern Montgomery County in southeastern Texas...
  Southwestern Walker County in southeastern Texas...

* Until 145 PM CDT.
    
* At 120 PM CDT, a severe thunderstorm capable of producing a tornado
  was located 13 miles west of Huntsville State Park, or 14 miles
  southwest of Huntsville, moving east at 30 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Huntsville and Huntsville State Park around 145 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3056 9579 3062 9581 3071 9554 3059 9550
TIME...MOT...LOC 1820Z 254DEG 25KT 3060 9575 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$
Cady
1 follow-up statement
140 
WWUS54 KHGX 121833
SVSHGX

Severe Weather Statement
National Weather Service Houston/Galveston TX
133 PM CDT Mon Jul 12 2021

TXC339-471-121842-
/O.CAN.KHGX.TO.W.0022.000000T0000Z-210712T1845Z/
Montgomery TX-Walker TX-
133 PM CDT Mon Jul 12 2021

...THE TORNADO WARNING FOR NORTHWESTERN MONTGOMERY AND SOUTHWESTERN
WALKER COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been cancelled.  However gusty winds are
still possible with this thunderstorm.

LAT...LON 3056 9579 3062 9581 3071 9554 3059 9550
TIME...MOT...LOC 1832Z 254DEG 25KT 3062 9565 

$$
Cady

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 7:21 PM CDTSpecial Weather StatementHGXHouston39 min
Jul 11, 7:39 PM CDTSpecial Weather StatementHGXHouston51 min
Jul 11, 7:58 PM CDTSpecial Weather StatementHGXHouston47 min
Jul 12, 8:29 AM CDTAreal Flood AdvisoryHGXBrazos, Madison3 hr
Jul 12, 9:03 AM CDTAreal Flood AdvisoryHGXWalker117 min
Jul 12, 9:08 AM CDTSpecial Weather StatementHGXSan Jacinto37 min
Jul 12, 9:36 AM CDTSpecial Weather StatementHGXSan Jacinto39 min
Jul 12, 10:12 AM CDTSpecial Weather StatementHGXLiberty, Polk, San Jacinto48 min
Jul 12, 11:29 AM CDTAreal Flood AdvisoryHGXBrazos, Madison3 hr
Jul 12, 11:33 AM CDTAreal Flood AdvisoryHGXHouston3 hr
Jul 12, 12:01 PM CDTSpecial Weather StatementHGXBrazos59 min
Jul 12, 12:43 PM CDTSevere Thunderstorm WarningHGXBrazos, Burleson18 min
Jul 12, 1:10 PM CDTAreal Flood AdvisoryHGXBrazos, Grimes110 min
Jul 12, 2:34 PM CDTSpecial Weather StatementHGXMontgomery, San Jacinto, Waller41 min
Jul 12, 3:06 PM CDTSpecial Weather StatementHGXHarris39 min
Jul 12, 3:43 PM CDTSpecial Weather StatementHGXFort Bend, Harris47 min
Jul 12, 4:31 PM CDTSpecial Weather StatementHGXChambers, Fort Bend59 min

Nearby

Tornado Warnings in Texas, 2021Every tornado warning in 2021Tornadoes 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.