Alert archive / Texas / Flash Flood Warnings in 2020

Flash Flood Warning 31, NWS Houston/Galveston, TX

September 22, 20204 counties in Texas

NWS Houston/Galveston, TX issued this flash flood warning at Sep 22, 2020, 8:57 PM CDT for 4 counties in Texas. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 22, 2020, 8:57 PM CDT (01:57 UTC)
Expired
Sep 22, 2020, 11:00 PM CDT
In force
2 hr
Issued by
NWS Houston/Galveston, TX
Area
Storm-based polygon
Flood severity
None

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

The radar

The Houston radar (KHGX), 59 km from the middle of the area, began a volume at 02:02 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

Shreveport, LA (KSHV), launched 00:00Z, 2.0 hours before the alert went out and 304 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, Shreveport, LA at 00:00Z on 2020-09-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Shreveport, LA at 00:00Z on 2020-09-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 173 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
522 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
173 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Houston/Galveston, TX wrote its last area forecast discussion before this flash flood warning went out at Sep 22, 6:56 PM CDT, 2 hours 1 minute earlier.

Area forecast discussion, Sep 22, 6:56 PM CDT, 2 hours 1 minute before
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The office that day

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

IssuedProductOfficeCountiesLasted
Sep 22, 7:01 PM CDTAreal Flood AdvisoryHGXBrazoria, Galveston, Harris4 hr
Sep 22, 7:49 PM CDTFlash Flood WarningHGXHarris, Waller3 hr
Sep 22, 8:18 PM CDTRiver Flood WarningHGXHarris6 hr
Sep 22, 9:05 PM CDTRiver Flood WarningHGXAustin, Colorado, Fort Bend, Wharton60 hr
Sep 22, 9:18 PM CDTRiver Flood WarningHGXBrazoria13 hr
Sep 22, 9:23 PM CDTRiver Flood WarningHGXHarris5 hr
Sep 22, 10:51 PM CDTAreal Flood WarningHGXFort Bend, Harris, Waller3 hr
Sep 22, 10:53 PM CDTRiver Flood WarningHGXHarris9 hr
Sep 23, 12:19 AM CDTAreal Flood AdvisoryHGXChambers, Harris, Liberty116 min
Sep 23, 7:14 AM CDTCoastal Flood AdvisoryHGXBrazoria, Galveston, Matagorda21 hr
Sep 23, 7:14 AM CDTRip Current StatementHGXBrazoria, Galveston, Matagorda6 hr

Nearby

Flash Flood Warnings in Texas, 2020Every flash flood warning in 2020

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.