Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 25, NWS Houston/Galveston, TX

June 28, 2021Chambers County, Harris County, Liberty County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Jun 28, 2021, 11:05 AM CDT for Chambers County, Harris County, Liberty 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: Jun 28, 2021, 11:05 AM CDT (16:05 UTC)
Expired: Jun 28, 2021, 2:15 PM CDT
In force: 3 hr
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon
Flood severity: None

Counties Chambers County, TX, Harris County, TX, Liberty County, TX

The radar

The Houston radar (KHGX), 30 km from the middle of the area, began a volume at 16:06 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 12:00Z, 4.1 hours before the alert went out and 183 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 983 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 635 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 151 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

As transmitted.

176 
WGUS54 KHGX 281605
FFWHGX
TXC071-201-291-281915-
/O.NEW.KHGX.FF.W.0025.210628T1605Z-210628T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
1105 AM CDT Mon Jun 28 2021

The National Weather Service in League City has issued a

* Flash Flood Warning for...
  Northwestern Chambers County in southeastern Texas...
  Northeastern Harris County in southeastern Texas...
  South Central Liberty County in southeastern Texas...

* Until 215 PM CDT.

* At 1105 AM CDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 4 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...
  Eastern Pasadena, Baytown, La Porte, Deer Park, Seabrook, Beach 
  City, Highlands, Barrett, Channelview, Cloverleaf, northeastern 
  Clear Lake, Mont Belvieu, Taylor Lake Village, El Lago, 
  Shoreacres, Old River-Winfree, Clear Lake Shores, Cove, Morgan's 
  Point and San Jacinto State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 2955 9503 2956 9505 2956 9507 2962 9513
      2976 9517 2985 9520 2990 9522 2990 9504
      2998 9496 2996 9486 2984 9479 2956 9500

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

kp

The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 28, 6:55 AM CDT	Areal Flood Advisory	HGX	Brazoria, Fort Bend, Harris	3 hr
Jun 28, 7:43 AM CDT	Areal Flood Advisory	HGX	Brazoria, Fort Bend, Wharton	2 hr
Jun 28, 8:37 AM CDT	Areal Flood Advisory	HGX	Harris	3 hr
Jun 28, 8:59 AM CDT	Rip Current Statement	HGX	Brazoria, Galveston, Matagorda	38 hr
Jun 28, 10:06 AM CDT	Areal Flood Advisory	HGX	Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty and 1 more	3 hr
Jun 28, 10:23 AM CDT	Areal Flood Advisory	HGX	Jackson, Matagorda	3 hr

Nearby

Flash Flood Warnings in Texas, 2021 Every 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.