Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 6, NWS Houston/Galveston, TX

May 16, 2021Jackson County, Matagorda County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at May 16, 2021, 2:13 PM CDT for Jackson County, Matagorda County, Texas. It was in force for 92 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: May 16, 2021, 2:13 PM CDT (19:13 UTC)
Expired: May 16, 2021, 3:45 PM CDT
In force: 92 min
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon
Flood severity: None

Counties Jackson County, TX, Matagorda County, TX

The radar

The Corpus Christi radar (KCRP), 148 km from the middle of the area, began a volume at 19:15 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

Corpus Christi, TX (KCRP), launched 12:00Z, 7.2 hours before the alert went out and 141 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: 2495 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 504 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 83 m²/s²
0-3 km storm-relative helicity: 230 m²/s²
Significant tornado parameter: 2.4
Supercell composite: 12.7

Open this sounding in Storm Lab

The text

As transmitted.

259 
WGUS54 KHGX 161913
FFWHGX
TXC239-321-162045-
/O.NEW.KHGX.FF.W.0006.210516T1913Z-210516T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
213 PM CDT Sun May 16 2021

The National Weather Service in League City has issued a

* Flash Flood Warning for...
  Southeastern Jackson County in south central Texas...
  West Central Matagorda County in southeastern Texas...

* Until 345 PM CDT.

* At 213 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  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...
  Matagorda, Palacios, South Texas Nuclear Plant, La Ward, Lolita, 
  Lake Texana Dam and Vanderbilt.

This includes the following streams and drainages...
  Willow Dam Slough, Navidad River, Venado Creek, Johnsons Timber 
  Slough, Lavaca River, Cox Creek, Cashs Creek, Colorado River, West 
  Carancahua Creek, Buttermilk Slough, Garcitas Creek, Tres Palacios 
  River, East Branch Mad Island Slough, Pelican Slough, Reed Creek, 
  East Matagorda Bay, Keller Creek, Fivemile Branch, East Carancahua 
  Creek, Turtle Creek and Little Robbins Slough.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2895 9660 2875 9587 2867 9592 2856 9623
      2858 9628 2861 9627 2860 9633 2864 9640
      2873 9641 2866 9646 2871 9653 2867 9653
      2871 9655 2867 9657 2870 9666 2876 9667
      2878 9670

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR 

$$

Cady

The office that day

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

Issued	Product	Office	Counties	Lasted
May 16, 6:30 AM CDT	Special Weather Statement	HGX	Matagorda	45 min
May 16, 7:00 AM CDT	Areal Flood Advisory	HGX	Matagorda	90 min
May 16, 7:41 AM CDT	Special Weather Statement	HGX	Matagorda	49 min
May 16, 8:32 AM CDT	Areal Flood Advisory	HGX	Brazoria, Jackson, Matagorda, Wharton	3 hr
May 16, 8:44 AM CDT	Flash Flood Warning	HGX	Brazoria, Jackson, Matagorda, Wharton	3 hr
May 16, 9:03 AM CDT	Flash Flood Watch	HGX	Austin, Brazoria, Colorado, Fort Bend, Jackson, Matagorda and 2 more	7 hr
May 16, 9:11 AM CDT	Areal Flood Advisory	HGX	Harris	64 min
May 16, 9:14 AM CDT	Special Weather Statement	HGX	Harris	46 min
May 16, 9:35 AM CDT	Flash Flood Warning	HGX	Colorado, Jackson, Wharton	115 min
May 16, 11:26 AM CDT	Flash Flood Warning	HGX	Brazoria, Colorado, Jackson, Matagorda, Wharton	4 hr
May 16, 11:37 AM CDT	River Flood Warning	HGX	Jackson, Wharton	29 hr
May 16, 11:39 AM CDT	River Flood Warning	HGX	Matagorda, Wharton	6 days
May 16, 12:06 PM CDT	Special Marine Warning	HGX		24 min
May 16, 2:07 PM CDT	Special Weather Statement	HGX	Matagorda	38 min
May 16, 2:31 PM CDT	Special Marine Warning	HGX		44 min
May 16, 2:47 PM CDT	Special Weather Statement	HGX	Matagorda	43 min
May 16, 3:08 PM CDT	Flash Flood Warning	HGX	Brazoria, Matagorda, Wharton	82 min
May 16, 3:24 PM CDT	Special Weather Statement	HGX	Matagorda	51 min
May 16, 3:31 PM CDT	River Flood Warning	HGX	Jackson	22 hr
May 16, 3:31 PM CDT	River Flood Warning	HGX	Jackson, Wharton	11 hr
May 16, 3:46 PM CDT	Flash Flood Warning	HGX	Matagorda	59 min
May 16, 5:04 PM CDT	Areal Flood Warning	HGX	Matagorda	101 min
May 16, 5:19 PM CDT	Special Marine Warning	HGX		56 min

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.