Alert archive / Texas / Flash Flood Warnings in 2021
Flash Flood Warning 32, NWS Houston/Galveston, TX
NWS Houston/Galveston, TX issued this flash flood warning at Sep 13, 2021, 9:46 PM CDT for Brazoria County, Galveston County, Matagorda County, Texas. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Sep 13, 2021, 9:46 PM CDT (02:46 UTC)
- Expired
- Sep 14, 2021, 1:45 AM CDT
- In force
- 4 hr
- Issued by
- NWS Houston/Galveston, TX
- Area
- Storm-based polygon
- Flood severity
- None
Counties Brazoria County, TX, Galveston County, TX, Matagorda County, TX
The radar
The Houston radar (KHGX), 33 km from the middle of the area, began a volume at 02:45 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 00:00Z, 2.8 hours before the alert went out and 219 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
- 528 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 794 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 53 m²/s²
- 0-3 km storm-relative helicity
- 327 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 2.3
The text
As transmitted.
586
WGUS54 KHGX 140246
FFWHGX
TXC039-167-321-140645-
/O.NEW.KHGX.FF.W.0032.210914T0246Z-210914T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
946 PM CDT Mon Sep 13 2021
The National Weather Service in League City has issued a
* Flash Flood Warning for...
Southeastern Brazoria County in southeastern Texas...
Galveston County in southeastern Texas...
East Central Matagorda County in southeastern Texas...
* Until 145 AM CDT.
* At 946 PM CDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Flash flooding is ongoing or
expected to begin shortly. Storms moving into the warned area
producing 2 to 3 inch per hour rainfall rates.
HAZARD...Flash flooding caused by bands of showers and
thunderstorms moving onshore associated with Tropical
Storm Nicholas.
SOURCE...Radar and reports from TxDOT.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Southern League City, Galveston Island West End, Galveston
Causeway, Texas City, Lake Jackson, Alvin, Angleton, Dickinson, La
Marque, Santa Fe, Freeport, Clute, Hitchcock, Surfside Beach,
Galveston Pier 21, Richwood, Brazoria, Jones Creek, Danbury and
Bayou Vista.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 2921 9543 2934 9534 2940 9519 2949 9501
2950 9490 2944 9484 2942 9484 2941 9481
2942 9481 2932 9470 2902 9516 2883 9542
2877 9557 2875 9561 2876 9563 2893 9568
FLASH FLOOD...RADAR INDICATED
$$
kpThe office that day
Everything else NWS Houston/Galveston, TX issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 13, 7:32 PM CDT | Flash Flood Warning | HGX | Brazoria, Jackson, Matagorda | 3 hr |
| Sep 13, 10:06 PM CDT | Hurricane Warning | HGX | Brazoria, Jackson, Matagorda | 6 hr |
| Sep 13, 10:31 PM CDT | Flash Flood Warning | HGX | Matagorda | 3 hr |
| Sep 14, 1:43 AM CDT | Flash Flood Warning | HGX | Brazoria, Galveston, Harris, Matagorda | 4 hr |
| Sep 14, 3:33 AM CDT | Flash Flood Warning | HGX | Brazoria, Chambers, Galveston, Harris | 4 hr |
| Sep 14, 3:57 AM CDT | Small Craft Advisory | HGX | 18 hr | |
| Sep 14, 4:04 AM CDT | Coastal Flood Advisory | HGX | Brazoria, Chambers, Galveston, Harris, Matagorda | 14 hr |
| Sep 14, 4:42 AM CDT | River Flood Warning | HGX | Galveston, Harris | 28 hr |
| Sep 14, 5:29 AM CDT | River Flood Warning | HGX | Galveston, Harris | 21 days |
| Sep 14, 5:31 AM CDT | River Flood Warning | HGX | Galveston, Harris | 21 days |
| Sep 14, 5:45 AM CDT | Flash Flood Warning | HGX | Brazoria, Chambers, Galveston, Harris | 3 hr |
| Sep 14, 8:11 AM CDT | Areal Flood Warning | HGX | Brazoria, Galveston, Harris | 3 hr |
Nearby
Flash Flood Warnings in Texas, 2021Every flash flood 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.