Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 21, NWS Houston/Galveston, TX

June 4, 2021Galveston County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Jun 4, 2021, 12:22 PM CDT for Galveston County, Texas. It was in force for 113 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
Jun 4, 2021, 12:22 PM CDT (17:22 UTC)
Expired
Jun 4, 2021, 2:15 PM CDT
In force
113 min
Issued by
NWS Houston/Galveston, TX
Area
Storm-based polygon
Flood severity
None

County Galveston County, TX

The radar

The Houston radar (KHGX), 10 km from the middle of the area, began a volume at 17:24 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, 5.4 hours before the alert went out and 187 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-pSkew-T log-p diagram, Lake Charles Mun, LA at 12:00Z on 2021-06-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 242 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 12:00Z on 2021-06-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
242 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
749 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
24 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

546 
WGUS54 KHGX 041722
FFWHGX
TXC167-041915-
/O.NEW.KHGX.FF.W.0021.210604T1722Z-210604T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
1222 PM CDT Fri Jun 4 2021

The National Weather Service in League City has issued a

* Flash Flood Warning for...
  North Central Galveston County in southeastern Texas...

* Until 215 PM CDT.

* At 1222 PM CDT, Doppler radar indicated 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 heavy rain.

  SOURCE...Doppler radar.

  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...
  Northeastern League City, Texas City, southern Seabrook, Kemah, 
  Nassau Bay, Clear Lake Shores, Bacliff, Kemah Boardwalk and San 
  Leon.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2955 9502 2956 9502 2957 9501 2956 9501
      2950 9491 2947 9493 2950 9501 2954 9508
      2956 9507 2956 9506 2956 9505 2955 9504
      2955 9503 2954 9502

FLASH FLOOD...RADAR INDICATED

$$
1 follow-up statement
090 
WGUS74 KHGX 041916
FFSHGX

Flash Flood Statement
National Weather Service Houston/Galveston TX
216 PM CDT Fri Jun 4 2021

TXC167-041926-
/O.EXP.KHGX.FF.W.0021.000000T0000Z-210604T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Galveston TX-
216 PM CDT Fri Jun 4 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR NORTH CENTRAL GALVESTON 
COUNTY...

The heavy rain has ended. Please continue to heed remaining road 
closures.

LAT...LON 2955 9502 2956 9502 2957 9501 2956 9501
      2950 9491 2947 9493 2950 9501 2954 9508
      2956 9507 2956 9506 2956 9505 2955 9504
      2955 9503 2954 9502

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 3, 7:02 PM CDTAreal Flood AdvisoryHGXHarris118 min
Jun 3, 7:26 PM CDTAreal Flood AdvisoryHGXHouston, Walker2 hr
Jun 3, 7:41 PM CDTSpecial Marine WarningHGX64 min
Jun 3, 8:21 PM CDTTornado WarningHGXBrazoria24 min
Jun 3, 8:37 PM CDTSpecial Marine WarningHGX83 min
Jun 3, 8:40 PM CDTTornado WarningHGXBrazoria20 min
Jun 3, 9:16 PM CDTSpecial Marine WarningHGX119 min
Jun 4, 1:03 AM CDTRiver Flood WarningHGXBrazoria, Fort Bend, Wharton7 days
Jun 4, 1:08 AM CDTRiver Flood WarningHGXBrazoria4 days
Jun 4, 4:03 AM CDTSmall Craft AdvisoryHGX6 hr
Jun 4, 7:09 AM CDTRiver Flood WarningHGXAustin, Colorado, Fort Bend, Wharton5 days
Jun 4, 10:24 AM CDTRiver Flood WarningHGXJackson40 hr
Jun 4, 10:26 AM CDTRiver Flood WarningHGXJackson3 days
Jun 4, 10:29 AM CDTAreal Flood AdvisoryHGXBrazoria2 hr
Jun 4, 10:43 AM CDTAreal Flood AdvisoryHGXGalveston2 hr
Jun 4, 11:23 AM CDTAreal Flood AdvisoryHGXGalveston, Harris112 min
Jun 4, 11:30 AM CDTSpecial Marine WarningHGX30 min
Jun 4, 12:31 PM CDTAreal Flood AdvisoryHGXBrazoria119 min
Jun 4, 12:34 PM CDTRiver Flood WarningHGXMatagorda, Wharton56 hr
Jun 4, 12:45 PM CDTAreal Flood AdvisoryHGXGalveston2 hr
Jun 4, 1:19 PM CDTAreal Flood AdvisoryHGXGalveston116 min
Jun 4, 1:21 PM CDTSpecial Marine WarningHGX39 min
Jun 4, 2:08 PM CDTSpecial Marine WarningHGX37 min
Jun 4, 2:14 PM CDTSpecial Marine WarningHGX46 min
Jun 4, 2:14 PM CDTSpecial Weather StatementHGXChambers46 min
Jun 4, 2:47 PM CDTSpecial Marine WarningHGX43 min
Jun 4, 3:48 PM CDTAreal Flood AdvisoryHGXBrazoria, Jackson, Matagorda, Wharton117 min
Jun 4, 6:12 PM CDTRip Current StatementHGXBrazoria, Galveston, Matagorda4 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.