Alert archive / Texas / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 39, NWS Houston/Galveston, TX
NWS Houston/Galveston, TX issued this severe thunderstorm warning at May 9, 2021, 8:00 PM CDT for Polk County, Trinity County, Texas. It was in force for 45 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
- May 9, 2021, 8:00 PM CDT (01:00 UTC)
- Expired
- May 9, 2021, 8:45 PM CDT
- In force
- 45 min
- Issued by
- NWS Houston/Galveston, TX
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Polk County, TX, Trinity County, TX
The radar
The Shreveport radar (KSHV), 176 km from the middle of the area, began a volume at 01:04 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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 9, 3:01 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Shreveport, LA (KSHV), launched 00:00Z, 1.0 hours before the alert went out and 184 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
- 1784 J/kg
- Mixed-layer CIN
- -30 J/kg
- Mixed-layer LCL
- 975 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 115 m²/s²
- 0-3 km storm-relative helicity
- 203 m²/s²
- Significant tornado parameter
- 1.7
- Supercell composite
- 8.5
The text
As transmitted.
792
WUUS54 KHGX 100100
SVRHGX
TXC373-455-100145-
/O.NEW.KHGX.SV.W.0039.210510T0100Z-210510T0145Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Houston/Galveston TX
800 PM CDT Sun May 9 2021
The National Weather Service in League City has issued a
* Severe Thunderstorm Warning for...
East central Trinity County in southeastern Texas...
North central Polk County in southeastern Texas...
* Until 845 PM CDT.
* At 800 PM CDT, a severe thunderstorm was located 7 miles north of
Groveton, or 9 miles southwest of Apple Springs, moving east at 20
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...
Apple Springs, Corrigan, Groveton and Pennington.
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.
&&
LAT...LON 3123 9486 3121 9486 3118 9485 3116 9485
3115 9486 3115 9484 3113 9482 3113 9480
3111 9476 3092 9485 3113 9527 3119 9524
3125 9515
TIME...MOT...LOC 0100Z 292DEG 16KT 3116 9510
HAIL...1.00IN
WIND...60MPH
$$2 follow-up statements
572
WWUS54 KHGX 100120
SVSHGX
Severe Weather Statement
National Weather Service Houston/Galveston TX
820 PM CDT Sun May 9 2021
TXC373-455-100145-
/O.CON.KHGX.SV.W.0039.000000T0000Z-210510T0145Z/
Trinity TX-Polk TX-
820 PM CDT Sun May 9 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR EAST CENTRAL TRINITY AND NORTH CENTRAL POLK COUNTIES...
At 820 PM CDT, a severe thunderstorm was located 7 miles south of
Apple Springs, moving east at 20 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Apple Springs and Corrigan.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
&&
LAT...LON 3123 9486 3121 9486 3118 9485 3116 9485
3115 9486 3115 9484 3113 9482 3113 9480
3111 9476 3092 9485 3104 9508 3112 9507
3120 9502 3124 9504
TIME...MOT...LOC 0120Z 292DEG 16KT 3113 9500
HAIL...1.00IN
WIND...60MPH
$$743
WWUS54 KHGX 100139
SVSHGX
Severe Weather Statement
National Weather Service Houston/Galveston TX
839 PM CDT Sun May 9 2021
TXC373-455-100148-
/O.EXP.KHGX.SV.W.0039.000000T0000Z-210510T0145Z/
Trinity TX-Polk TX-
839 PM CDT Sun May 9 2021
...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL TRINITY AND NORTH
CENTRAL POLK COUNTIES WILL EXPIRE AT 845 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.
A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
southeastern Texas.
LAT...LON 3123 9486 3121 9486 3118 9485 3116 9485
3115 9486 3115 9484 3113 9482 3113 9480
3111 9476 3092 9485 3104 9508 3112 9507
3120 9502 3124 9504
TIME...MOT...LOC 0138Z 292DEG 16KT 3111 9495
$$The office that day
Everything else NWS Houston/Galveston, TX issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 9, 7:20 PM CDT | Special Weather Statement | HGX | Houston, Trinity | 55 min |
| May 9, 9:47 PM CDT | Areal Flood Advisory | HGX | Houston, Trinity | 58 min |
| May 9, 10:59 PM CDT | Areal Flood Advisory | HGX | Houston | 2 hr |
| May 10, 5:28 PM CDT | Special Weather Statement | HGX | Polk | 32 min |
| May 10, 6:01 PM CDT | Special Weather Statement | HGX | Polk | 44 min |
| May 10, 6:09 PM CDT | Areal Flood Advisory | HGX | Polk, Trinity | 2 hr |
| May 10, 6:32 PM CDT | Areal Flood Advisory | HGX | Polk | 58 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.