Alert archive / Texas / Flash Flood Warnings in 2021
Flash Flood Warning 37, NWS Houston/Galveston, TX
NWS Houston/Galveston, TX issued this flash flood warning at Oct 1, 2021, 6:04 AM CDT for Harris County, Texas. It was in force for 3 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
- Oct 1, 2021, 6:04 AM CDT (11:04 UTC)
- Expired
- Oct 1, 2021, 9:00 AM CDT
- In force
- 3 hr
- Issued by
- NWS Houston/Galveston, TX
- Area
- Storm-based polygon
- Flood severity
- None
County Harris County, TX
The radar
The Houston radar (KHGX), 43 km from the middle of the area, began a volume at 11:03 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, 11.1 hours before the alert went out and 182 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
- 316 J/kg
- Mixed-layer CIN
- -57 J/kg
- Mixed-layer LCL
- 796 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 96 m²/s²
- 0-3 km storm-relative helicity
- 126 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.6
The text
As transmitted.
263
WGUS54 KHGX 011104
FFWHGX
TXC201-011400-
/O.NEW.KHGX.FF.W.0037.211001T1104Z-211001T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
604 AM CDT Fri Oct 1 2021
The National Weather Service in League City has issued a
* Flash Flood Warning for...
Northeastern Harris County in southeastern Texas...
* Until 900 AM CDT.
* At 604 AM CDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
2 and 5 inches of rain have fallen. Nearly three inches of rain
has fallen in Crosby in the past hour. Flash flooding is ongoing
or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
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...
Northwestern Baytown, Deer Park, Barrett, Highlands, Channelview,
Cloverleaf, Crosby, Sheldon, Lake Houston Dam, San Jacinto State
Park, eastern Houston Ship Channel, Lake Houston and Northshore.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 2973 9506 2972 9509 2972 9513 2978 9519
2982 9520 2985 9520 2993 9517 2996 9514
2998 9508 3000 9506 2999 9501 2997 9499
2996 9498 2992 9500 2991 9499 2989 9498
2986 9497 2976 9505 2974 9505
FLASH FLOOD...RADAR AND GAUGE INDICATED
$$2 follow-up statements
266
WGUS74 KHGX 011140
FFSHGX
Flash Flood Statement
National Weather Service Houston/Galveston TX
640 AM CDT Fri Oct 1 2021
TXC201-011400-
/O.CON.KHGX.FF.W.0037.000000T0000Z-211001T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Harris TX-
640 AM CDT Fri Oct 1 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 9 AM CDT THIS MORNING
FOR NORTHEASTERN HARRIS COUNTY...
At 640 AM CDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between 3
and 6 inches of rain have fallen. Additional rainfall amounts of 1
to 2 inches are possible, primarily in the northern portion of the
warned area. Flash flooding is ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Northwestern Baytown, Deer Park, Barrett, Highlands, Channelview,
Cloverleaf, Crosby, Sheldon, Lake Houston Dam, San Jacinto State
Park, eastern Houston Ship Channel, Lake Houston and Northshore.
Rain rates are beginning to slow, but a gauge at Gum Gully Creek in
Crosby has still reported 2 inches of rain in the past hour (5.72
inches total) and rain rates are still an inch per hour at the US-90
bridge over the San Jacinto River.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 2973 9506 2972 9509 2972 9513 2978 9519
2982 9520 2985 9520 2993 9517 2996 9514
2998 9508 3000 9506 2999 9501 2997 9499
2996 9498 2992 9500 2991 9499 2989 9498
2986 9497 2976 9505 2974 9505
FLASH FLOOD...RADAR AND GAUGE INDICATED
$$008
WGUS74 KHGX 011405
FFSHGX
Flash Flood Statement
National Weather Service Houston/Galveston TX
905 AM CDT Fri Oct 1 2021
TXC201-011415-
/O.EXP.KHGX.FF.W.0037.000000T0000Z-211001T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Harris TX-
905 AM CDT Fri Oct 1 2021
...FLASH FLOOD WARNING HAS EXPIRED FOR NORTHEASTERN HARRIS COUNTY
AND HAS BEEN REPLACED WITH A FLOOD WARNING FOR REMAINING HIGH
WATER...
The heavy rain has ended. However, flooding from the heavy rains may
pose a threat until the waters recede, and another flood warning has
been issued for the threat from those high waters. Please continue
to heed remaining road closures.
LAT...LON 2973 9506 2972 9509 2972 9513 2978 9519
2982 9520 2985 9520 2993 9517 2996 9514
2998 9508 3000 9506 2999 9501 2997 9499
2996 9498 2992 9500 2991 9499 2989 9498
2986 9497 2976 9505 2974 9505
$$The office that day
Everything else NWS Houston/Galveston, TX issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 1, 5:37 AM CDT | Areal Flood Advisory | HGX | Chambers, Harris, Liberty | 27 min |
| Oct 1, 5:57 AM CDT | Areal Flood Advisory | HGX | Austin, Grimes, Waller, Washington | 2 hr |
| Oct 1, 6:52 AM CDT | Areal Flood Advisory | HGX | Harris | 113 min |
| Oct 1, 7:23 AM CDT | Areal Flood Advisory | HGX | Fort Bend, Harris, Waller | 67 min |
| Oct 1, 7:40 AM CDT | Areal Flood Advisory | HGX | Austin, Grimes, Harris, Waller, Washington | 99 min |
| Oct 1, 8:29 AM CDT | Flash Flood Warning | HGX | Fort Bend, Harris, Waller | 3 hr |
| Oct 1, 8:34 AM CDT | Areal Flood Advisory | HGX | Harris, Montgomery | 65 min |
| Oct 1, 8:38 AM CDT | Flash Flood Warning | HGX | Polk, San Jacinto, Trinity | 3 hr |
| Oct 1, 9:01 AM CDT | Areal Flood Warning | HGX | Chambers, Harris, Liberty | 5 hr |
| Oct 1, 9:19 AM CDT | Flash Flood Warning | HGX | Grimes, Waller, Washington | 3 hr |
| Oct 1, 9:25 AM CDT | Areal Flood Advisory | HGX | Fort Bend | 3 hr |
| Oct 1, 9:37 AM CDT | Areal Flood Advisory | HGX | Harris | 3 hr |
| Oct 1, 10:57 AM CDT | Areal Flood Warning | HGX | Fort Bend, Harris, Waller | 3 hr |
| Oct 1, 11:01 AM CDT | Areal Flood Advisory | HGX | Liberty, San Jacinto | 3 hr |
| Oct 1, 11:08 AM CDT | River Flood Warning | HGX | Harris | 4 hr |
| Oct 1, 11:54 AM CDT | Areal Flood Advisory | HGX | Polk, San Jacinto, Trinity | 2 hr |
| Oct 1, 12:02 PM CDT | Areal Flood Warning | HGX | Austin, Grimes, Harris, Waller, Washington | 2 hr |
| Oct 1, 12:42 PM CDT | Areal Flood Advisory | HGX | Fort Bend, Harris, Montgomery | 78 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.