Alert archive / Texas / Flash Flood Warnings in 2018

Flash Flood Warning 21, NWS Houston/Galveston, TX

September 3, 2018Brazoria County, Chambers County, Galveston County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Sep 3, 2018, 7:43 AM CDT for Brazoria County, Chambers County, Galveston County, Texas. It was in force for 8 hr. 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
Sep 3, 2018, 7:43 AM CDT (12:43 UTC)
Expired
Sep 3, 2018, 3:45 PM CDT
In force
8 hr
Issued by
NWS Houston/Galveston, TX
Area
Storm-based polygon
Flood severity
None

Counties Brazoria County, TX, Chambers County, TX, Galveston County, TX

The radar

The Houston radar (KHGX), 43 km from the middle of the area, began a volume at 12:45 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

TimeReportWhereRemark
Sep 3, 9:00 AM CDTFLASH FLOODGalveston, TXNUMEROUS ROADS IMPASSABLE DUE TO HIGH WATER INCLUDING 25TH FROM AVE P TO BROADWAY, FERRY ROAD. HARBORSIDE DR TOWARD UTMB. PORTIONS OF THE STRAND.

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, 0.7 hours before the alert went out and 160 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 2018-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 269 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 2018-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 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
269 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
615 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
106 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

502 
WGUS54 KHGX 031243
FFWHGX
TXC039-071-167-031545-
/O.NEW.KHGX.FF.W.0021.180903T1243Z-180903T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
743 AM CDT MON SEP 3 2018

The National Weather Service in League City has issued a

* Flash Flood Warning for...
  Central Galveston County in southeastern Texas...
  Southeastern Chambers County in southeastern Texas...
  Southeastern Brazoria County in southeastern Texas...

* Until 1045 AM CDT.

* At 741 AM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to 
  begin shortly. Almost 9.00 inches of rain has fallen at the gage 
  at the Galveston Intercoastal Water Way at Highway 124 in Chambers 
  County in the last 7 hours.

* Some locations that will experience flooding include...
  Galveston Causeway, Galveston Island West End, Texas City, La
  Marque, Hitchcock, Surfside Beach, Galveston Pier 21, Bayou Vista,
  Oyster Creek, Jamaica Beach, Tiki Island, High Island, Scholes
  Field, Port Bolivar, Offatts Bayou, Galveston Pleasure Pier,
  Pelican Island, Galveston State Park, Crystal Beach and
  Schlitterbahn.

LAT...LON 2955 9439 2947 9436 2893 9527 2903 9538
      2980 9436 2956 9435

$$
3 follow-up statements
050 
WGUS74 KHGX 031346
FFSHGX

Flash Flood Statement
National Weather Service Houston/Galveston TX
846 AM CDT MON SEP 3 2018

TXC039-071-167-031545-
/O.CON.KHGX.FF.W.0021.000000T0000Z-180903T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Galveston TX-Chambers TX-Brazoria TX-
846 AM CDT MON SEP 3 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 AM CDT FOR
CENTRAL GALVESTON...SOUTHEASTERN CHAMBERS AND SOUTHEASTERN BRAZORIA
COUNTIES...

At 845 AM CDT, local law enforcement reported flooded and impassable 
roads across Galveston Island. Flash flooding is already occurring.

Some locations that will experience flooding include...
Galveston Causeway, Galveston Island West End, Texas City, La Marque,
Hitchcock, Surfside Beach, Galveston Pier 21, Bayou Vista, Oyster
Creek, Jamaica Beach, Tiki Island, High Island, Scholes Field, Port
Bolivar, Offatts Bayou, Galveston Pleasure Pier, Pelican Island,
Galveston State Park, Crystal Beach and Schlitterbahn.

Additional heavy rainfall is expected in the warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 2955 9439 2947 9436 2893 9527 2903 9538
      2980 9436 2956 9435

$$
11
001 
WGUS54 KHGX 031518
FFWHGX
TXC039-071-167-031845-
/O.EXT.KHGX.FF.W.0021.000000T0000Z-180903T1845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
1018 AM CDT MON SEP 3 2018

The National Weather Service in League City has extended the

* Flash Flood Warning for...
  Central Galveston County in southeastern Texas...
  Southeastern Chambers County in southeastern Texas...
  Southeastern Brazoria County in southeastern Texas...

* Until 145 PM CDT.

* At 1017 AM CDT, local law enforcement reported heavy rain across 
  the warned area. 5 to 10 inches of rain have already fallen. Flash 
  flooding is already occurring.

* Some locations that will experience flooding include...
  Galveston Causeway, Galveston Island West End, Texas City, La
  Marque, Hitchcock, Surfside Beach, Galveston Pier 21, Bayou Vista,
  Oyster Creek, Jamaica Beach, Tiki Island, High Island, Scholes
  Field, Port Bolivar, Offatts Bayou, Galveston Pleasure Pier,
  Pelican Island, Galveston State Park, Crystal Beach and
  Schlitterbahn.

Additional rainfall amounts of 1 to 3 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.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 2955 9439 2947 9436 2893 9527 2903 9538
      2980 9436 2956 9435

$$
11
033 
WGUS54 KHGX 031835
FFWHGX
TXC039-071-167-032045-
/O.EXT.KHGX.FF.W.0021.000000T0000Z-180903T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
135 PM CDT MON SEP 3 2018

The National Weather Service in League City has extended the

* Flash Flood Warning for...
  Central Galveston County in southeastern Texas...
  Southeastern Chambers County in southeastern Texas...
  Southeastern Brazoria County in southeastern Texas...

* Until 345 PM CDT.

* At 135 PM CDT, local law enforcement reported heavy rain across 
  the warned area. Many streets on Galveston Island are 
  impassable. Flash flooding is already occurring.

* Some locations that will experience flooding include...
  Galveston Causeway, Galveston Island West End, Texas City, La
  Marque, Hitchcock, Surfside Beach, Galveston Pier 21, Bayou Vista,
  Oyster Creek, Jamaica Beach, Tiki Island, High Island, Scholes
  Field, Port Bolivar, Offatts Bayou, Galveston Pleasure Pier,
  Pelican Island, Galveston State Park, Crystal Beach and
  Schlitterbahn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 2955 9439 2947 9436 2893 9527 2903 9538
      2980 9436 2956 9435

$$
11

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 3, 4:25 AM CDTAreal Flood AdvisoryHGXChambers, Galveston2 hr
Sep 3, 4:55 AM CDTFlash Flood WarningHGXChambers, Galveston3 hr
Sep 3, 6:34 AM CDTAreal Flood AdvisoryHGXBrazoria, Galveston, Matagorda116 min
Sep 3, 6:52 AM CDTAreal Flood AdvisoryHGXGalveston113 min
Sep 3, 7:21 AM CDTSpecial Marine WarningHGX39 min
Sep 3, 7:24 AM CDTAreal Flood AdvisoryHGXBrazoria, Galveston, Harris2 hr
Sep 3, 7:28 AM CDTAreal Flood AdvisoryHGXChambers, Galveston, Harris2 hr
Sep 3, 7:37 AM CDTSpecial Weather StatementHGXBrazoria38 min
Sep 3, 8:25 AM CDTFlash Flood WarningHGXBrazoria, Matagorda5 hr
Sep 3, 9:09 AM CDTAreal Flood AdvisoryHGXHarris2 hr
Sep 3, 9:11 AM CDTAreal Flood AdvisoryHGXBrazoria, Matagorda2 hr
Sep 3, 9:13 AM CDTAreal Flood AdvisoryHGXChambers, Galveston, Harris, Liberty6 hr
Sep 3, 9:43 AM CDTAreal Flood AdvisoryHGXHarris, Liberty, Montgomery62 min
Sep 3, 9:53 AM CDTSpecial Marine WarningHGX37 min
Sep 3, 10:13 AM CDTAreal Flood AdvisoryHGXAustin, Grimes, Harris, Waller, Washington2 hr
Sep 3, 10:43 AM CDTAreal Flood AdvisoryHGXHarris, Montgomery2 hr
Sep 3, 3:19 PM CDTAreal Flood WarningHGXBrazoria, Chambers, Galveston3 hr

Nearby

Flash Flood Warnings in Texas, 2018Every flash flood warning in 2018

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.