Alert archive / Texas / Flash Flood Warnings in 2021
Flash Flood Warning 29, NWS Houston/Galveston, TX
NWS Houston/Galveston, TX issued this flash flood warning at Jul 21, 2021, 3:09 PM CDT for Harris County, Texas. It was in force for 51 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 21, 2021, 3:09 PM CDT (20:09 UTC)
- Expired
- Jul 21, 2021, 4:00 PM CDT
- In force
- 51 min
- Issued by
- NWS Houston/Galveston, TX
- Area
- Storm-based polygon
- Flood severity
- None
County Harris County, TX
The radar
The Houston radar (KHGX), 60 km from the middle of the area, began a volume at 20:09 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 21, 3:26 PM CDT | FLASH FLOOD | 1 Wnw Hedwig Village, TX | ROADWAY FLOODING OCCURRED ALONG THE I-10 FRONTAGE ROAD AND IN AREAS SURROUNDING THE MEMORIAL CITY MALL. MULTIPLE CARS WERE STALLED AS A RESULT OF THE FLOODWATERS. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Lake Charles Mun, LA (KLCH), launched 12:00Z, 8.2 hours before the alert went out and 229 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
- 539 J/kg
- Mixed-layer CIN
- -36 J/kg
- Mixed-layer LCL
- 805 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 5 m²/s²
- 0-3 km storm-relative helicity
- 12 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
766
WGUS54 KHGX 212009
FFWHGX
TXC201-212100-
/O.NEW.KHGX.FF.W.0029.210721T2009Z-210721T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
309 PM CDT Wed Jul 21 2021
The National Weather Service in League City has issued a
* Flash Flood Warning for...
Harris County in southeastern Texas...
* Until 400 PM CDT.
* At 309 PM CDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 2 and 3 inches of rain
have fallen. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Doppler radar and automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
* Some locations that will experience flash flooding include...
Jersey Village, Hunters Creek Village, Bunker Hill Village, Piney
Point Village, Spring Branch North, Spring Branch West, Spring
Valley, eastern Addicks Park Ten, Hedwig Village, Hilshire
Village, Westbranch, Spring Branch Central, Carverdale, Fairbanks
/ Northwest Crossing, Langwood, Spring Branch East, Greater
Inwood, Greater Uptown, Central Northwest and Memorial.
Additional rainfall amounts up to 1 inch are possible in the warned
area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses
as well as other drainage areas and low lying spots.
&&
LAT...LON 2977 9560 2976 9549 2989 9548 2988 9560
FLASH FLOOD...RADAR AND GAUGE INDICATED
$$
Cady1 follow-up statement
807 WGUS74 KHGX 212057 FFSHGX Flash Flood Statement National Weather Service Houston/Galveston TX 357 PM CDT Wed Jul 21 2021 TXC201-212107- /O.EXP.KHGX.FF.W.0029.000000T0000Z-210721T2100Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Harris TX- 357 PM CDT Wed Jul 21 2021 ...FLASH FLOOD WARNING WILL EXPIRE AT 4 PM CDT THIS AFTERNOON FOR HARRIS COUNTY... The heavy rain has ended. Flooding is no longer expected to pose a threat. Please continue to heed remaining road closures and do not drive across flooded roadways. LAT...LON 2977 9560 2976 9549 2989 9548 2988 9560 $$ Cady
The office that day
Everything else NWS Houston/Galveston, TX issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 8:46 PM CDT | River Flood Warning | HGX | Brazoria, Fort Bend, Wharton | 35 hr |
| Jul 21, 1:06 PM CDT | Areal Flood Advisory | HGX | Brazoria, Fort Bend, Harris | 114 min |
| Jul 21, 1:17 PM CDT | Special Weather Statement | HGX | Fort Bend | 43 min |
| Jul 21, 1:33 PM CDT | Special Weather Statement | HGX | Brazoria | 57 min |
| Jul 21, 1:39 PM CDT | Severe Thunderstorm Warning | HGX | Brazoria, Galveston, Harris | 32 min |
| Jul 21, 1:46 PM CDT | Areal Flood Advisory | HGX | Brazoria, Galveston, Harris | 74 min |
| Jul 21, 2:34 PM CDT | Areal Flood Advisory | HGX | Harris | 116 min |
| Jul 21, 2:34 PM CDT | Special Weather Statement | HGX | Harris | 26 min |
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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.