Alert archive / Texas / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 79, NWS Houston/Galveston, TX
NWS Houston/Galveston, TX issued this severe thunderstorm warning at Aug 18, 2021, 2:54 PM CDT for 4 counties in Texas. It was in force for 51 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, 2:54 PM CDT (19:54 UTC)
- Expired
- Aug 18, 2021, 3:45 PM CDT
- In force
- 51 min
- Issued by
- NWS Houston/Galveston, TX
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Houston County, TX, Madison County, TX, Trinity County, TX, Walker County, TX
The radar
The Houston radar (KHGX), 174 km from the middle of the area, began a volume at 19:57 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
Shreveport, LA (KSHV), launched 12:00Z, 7.9 hours before the alert went out and 237 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.
- 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
The text
As transmitted.
966 WUUS54 KHGX 181954 SVRHGX TXC225-313-455-471-182045- /O.NEW.KHGX.SV.W.0079.210818T1954Z-210818T2045Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Houston/Galveston TX 254 PM CDT Wed Aug 18 2021 The National Weather Service in League City has issued a * Severe Thunderstorm Warning for... West central Trinity County in southeastern Texas... Southwestern Houston County in southeastern Texas... Northeastern Madison County in southeastern Texas... Northern Walker County in southeastern Texas... * Until 345 PM CDT. * At 254 PM CDT, a severe thunderstorm was located 14 miles west of Trinity, or 16 miles south of Austonio, moving northeast at 30 mph. HAZARD...60 mph wind gusts and penny size hail. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. * Locations impacted include... Austonio, Trinity and Lovelady. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. Large hail and damaging winds and continuous cloud to ground lightning is occurring with this storm. Move indoors immediately. Lightning is one of nature's leading killers. Remember, if you can hear thunder, you are close enough to be struck by lightning. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3077 9555 3090 9580 3133 9562 3114 9518 TIME...MOT...LOC 1954Z 213DEG 27KT 3095 9562 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...0.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ CB
3 follow-up statements
227
WWUS54 KHGX 182015
SVSHGX
Severe Weather Statement
National Weather Service Houston/Galveston TX
315 PM CDT Wed Aug 18 2021
TXC225-313-455-471-182045-
/O.CON.KHGX.SV.W.0079.000000T0000Z-210818T2045Z/
Trinity TX-Houston TX-Madison TX-Walker TX-
315 PM CDT Wed Aug 18 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR WEST CENTRAL TRINITY...SOUTHWESTERN HOUSTON...NORTHEASTERN
MADISON AND NORTHEASTERN WALKER COUNTIES...
At 315 PM CDT, a severe thunderstorm was located near Lovelady, or 9
miles southeast of Austonio, moving northeast at 30 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Austonio and Lovelady.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 3089 9543 3092 9555 3100 9576 3133 9562
3117 9525
TIME...MOT...LOC 2015Z 213DEG 27KT 3108 9552
HAIL...<.75IN
WIND...60MPH
$$
CB373
WWUS54 KHGX 182037
SVSHGX
Severe Weather Statement
National Weather Service Houston/Galveston TX
337 PM CDT Wed Aug 18 2021
TXC313-455-471-182046-
/O.CAN.KHGX.SV.W.0079.000000T0000Z-210818T2045Z/
Trinity TX-Madison TX-Walker TX-
337 PM CDT Wed Aug 18 2021
...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL TRINITY...
NORTHEASTERN MADISON 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.
LAT...LON 3107 9542 3116 9569 3133 9562 3120 9533
TIME...MOT...LOC 2036Z 213DEG 27KT 3121 9542
$$
TXC225-182045-
/O.CON.KHGX.SV.W.0079.000000T0000Z-210818T2045Z/
Houston TX-
337 PM CDT Wed Aug 18 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR SOUTHWESTERN HOUSTON COUNTY...
At 336 PM CDT, a severe thunderstorm was located near Lovelady, or 7
miles south of Crockett, moving northeast at 30 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Austonio and Lovelady.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3107 9542 3116 9569 3133 9562 3120 9533
TIME...MOT...LOC 2036Z 213DEG 27KT 3121 9542
HAIL...<.75IN
WIND...60MPH
$$
CB551
WWUS54 KHGX 182043
SVSHGX
Severe Weather Statement
National Weather Service Houston/Galveston TX
343 PM CDT Wed Aug 18 2021
TXC225-182053-
/O.EXP.KHGX.SV.W.0079.000000T0000Z-210818T2045Z/
Houston TX-
343 PM CDT Wed Aug 18 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN HOUSTON COUNTY
WILL EXPIRE AT 345 PM CDT...
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 will be allowed to expire.
LAT...LON 3107 9542 3116 9569 3133 9562 3120 9533
TIME...MOT...LOC 2043Z 213DEG 27KT 3123 9540
$$
CBThe office that day
Everything else NWS Houston/Galveston, TX issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 1:33 PM CDT | Areal Flood Advisory | HGX | Harris | 57 min |
| Aug 18, 1:44 PM CDT | Special Weather Statement | HGX | Montgomery | 46 min |
| Aug 18, 1:54 PM CDT | Special Weather Statement | HGX | Walker | 51 min |
| Aug 18, 2:25 PM CDT | Special Weather Statement | HGX | Brazos, Burleson | 50 min |
| Aug 18, 2:31 PM CDT | Special Weather Statement | HGX | Madison, Walker | 44 min |
| Aug 18, 3:32 PM CDT | Severe Thunderstorm Warning | HGX | Houston | 12 min |
| Aug 18, 3:46 PM CDT | Special Weather Statement | HGX | Houston | 29 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.