Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 19, NWS Houston/Galveston, TX

June 1, 2021Houston County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Jun 1, 2021, 12:36 AM CDT for Houston County, Texas. It was in force for 3 hr. 2 reports 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: Jun 1, 2021, 12:36 AM CDT (05:36 UTC)
Expired: Jun 1, 2021, 3:45 AM CDT
In force: 3 hr
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon
Flood severity: None

County Houston County, TX

The radar

The Shreveport radar (KSHV), 178 km from the middle of the area, began a volume at 05:35 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

Time	Report	Where	Remark
Jun 1, 3:00 AM CDT	FLASH FLOOD	1 Ese Grapeland, TX	TEXAS DEPARTMENT OF TRANSPORTATION REPORTS A WASHOUT IN ONE LANE OF FM 2423 BETWEEN COUNTY ROAD 1840 AND US HIGHWAY 287 NORTH DUE TO FLASH FLOODING.
Jun 1, 3:00 AM CDT	FLASH FLOOD	2 Ne Grapeland, TX	SWIFT WATER RESCUE WAS MADE ALONG FM228 APPROXIMATELY 2 MILES EAST OF GRAPELAND AFTER A CAR WAS SWEPT OFF THE ROAD BY FLOODWATERS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 5.6 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-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: 140 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1307 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 129 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.3

Open this sounding in Storm Lab

The text

As transmitted.

817 
WGUS54 KHGX 010536
FFWHGX
TXC225-010845-
/O.NEW.KHGX.FF.W.0019.210601T0536Z-210601T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Houston/Galveston TX
1236 AM CDT Tue Jun 1 2021

The National Weather Service in League City has issued a

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

* Until 345 AM CDT.

* At 1236 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 3 and 8 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar and trained spotter.

  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...
  Grapeland.

This includes the following streams and drainages...
  Bennett Creek, Silver Creek, Hays Branch, Little Elkhart Creek, 
  Peter Branch, Cook Branch, Austin Branch, Gum Creek, Hammond 
  Creek, Hurricane Bayou, San Pedro Creek, Hickory Creek, Sands 
  Branch, Caney Creek, Little Creek, Miles Creek, Big Elkhart Creek, 
  Stroud Branch and Neches River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, country roads, farmland, and other low lying 
spots.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3159 9528 3151 9523 3146 9528 3141 9539
      3141 9545 3154 9565

FLASH FLOOD...RADAR INDICATED

$$

kp

The office that day

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

Issued	Product	Office	Counties	Lasted
May 31, 9:14 PM CDT	River Flood Warning	HGX	Brazoria, Fort Bend, Wharton	61 hr
Jun 1, 3:34 AM CDT	Flash Flood Warning Considerable damage threat	HGX	Houston	3 hr
Jun 1, 3:46 AM CDT	Areal Flood Advisory	HGX	Brazos, Burleson, Madison	3 hr
Jun 1, 6:08 AM CDT	Areal Flood Warning	HGX	Houston	6 hr
Jun 1, 10:29 AM CDT	River Flood Warning	HGX	Houston, Madison, Trinity, Walker	3 days
Jun 1, 3:09 PM CDT	Special Marine Warning	HGX		36 min
Jun 1, 3:39 PM CDT	Special Marine Warning	HGX		51 min
Jun 1, 4:22 PM CDT	Special Marine Warning	HGX		113 min
Jun 1, 6:17 PM CDT	Special Marine Warning	HGX		88 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.