Alert archive / Texas / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 80, NWS Houston/Galveston, TX

August 18, 2021Houston County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at Aug 18, 2021, 3:32 PM CDT for Houston 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
Aug 18, 2021, 3:32 PM CDT (20:32 UTC)
Expired
Aug 18, 2021, 3:44 PM CDT
In force
12 min
Issued by
NWS Houston/Galveston, TX
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Houston County, TX

The radar

The Shreveport radar (KSHV), 186 km from the middle of the area, began a volume at 20:31 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 (KSHV), launched 12:00Z, 8.5 hours before the alert went out and 195 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, Shreveport, LA at 12:00Z on 2021-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 453 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, Shreveport, LA at 12:00Z on 2021-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 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
453 J/kg
Mixed-layer CIN
-85 J/kg
Mixed-layer LCL
995 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
58 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

029 
WUUS54 KHGX 182032
SVRHGX
TXC225-182115-
/O.NEW.KHGX.SV.W.0080.210818T2032Z-210818T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Houston/Galveston TX
332 PM CDT Wed Aug 18 2021

The National Weather Service in League City has issued a

* Severe Thunderstorm Warning for...
  Northwestern Houston County in southeastern Texas...

* Until 415 PM CDT.

* At 331 PM CDT, a severe thunderstorm was located near Lovelady, or
  7 miles east of Austonio, moving north at 30 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Crockett, Grapeland and Latexo. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3152 9523 3120 9533 3132 9562 3155 9560
      3156 9552
TIME...MOT...LOC 2031Z 193DEG 28KT 3120 9551 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CB
1 follow-up statement
418 
WWUS54 KHGX 182044
SVSHGX

Severe Weather Statement
National Weather Service Houston/Galveston TX
344 PM CDT Wed Aug 18 2021

TXC225-182053-
/O.CAN.KHGX.SV.W.0080.000000T0000Z-210818T2115Z/
Houston TX-
344 PM CDT Wed Aug 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN HOUSTON COUNTY IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.

LAT...LON 3152 9523 3120 9533 3132 9562 3155 9560
      3156 9552
TIME...MOT...LOC 2039Z 193DEG 28KT 3130 9548 

$$

CB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 1:33 PM CDTAreal Flood AdvisoryHGXHarris57 min
Aug 18, 1:44 PM CDTSpecial Weather StatementHGXMontgomery46 min
Aug 18, 1:54 PM CDTSpecial Weather StatementHGXWalker51 min
Aug 18, 2:25 PM CDTSpecial Weather StatementHGXBrazos, Burleson50 min
Aug 18, 2:31 PM CDTSpecial Weather StatementHGXMadison, Walker44 min
Aug 18, 2:54 PM CDTSevere Thunderstorm WarningHGXHouston, Madison, Trinity, Walker51 min
Aug 18, 3:46 PM CDTSpecial Weather StatementHGXHouston29 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.