Alert archive / Texas / Flash Flood Warnings in 2021

Flash Flood Warning 23, NWS Fort Worth, TX

August 18, 2021Somervell County, Texas

NWS Fort Worth, TX issued this flash flood warning at Aug 18, 2021, 4:26 PM CDT for Somervell County, Texas. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 18, 2021, 4:26 PM CDT (21:26 UTC)
Expired: Aug 18, 2021, 7:30 PM CDT
In force: 3 hr
Issued by: NWS Fort Worth, TX
Area: Storm-based polygon
Flood severity: None

County Somervell County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 56 km from the middle of the area, began a volume at 21:29 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

Fort Worth, TX (KFWD), launched 12:00Z, 9.4 hours before the alert went out and 79 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: 500 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 580 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: -15 m²/s²
0-3 km storm-relative helicity: -2 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

033 
WGUS54 KFWD 182126
FFWFWD
TXC425-190030-
/O.NEW.KFWD.FF.W.0023.210818T2126Z-210819T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Fort Worth TX
426 PM CDT Wed Aug 18 2021

The National Weather Service in Fort Worth has issued a

* Flash Flood Warning for...
  Central Somervell County in north central Texas...

* Until 730 PM CDT.

* At 426 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. The expected rainfall rate is 4 inches in 1 hour. 
  Additional rainfall amounts of 2 to 3 inches are possible. Flash 
  flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets, and underpasses as well as other
           poor drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Glen Rose and Dinosaur Valley State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

&&

LAT...LON 3229 9773 3231 9768 3224 9764 3222 9768
      3212 9788 3221 9793

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...4 INCHES IN 1 HOUR

$$

Stalley

1 follow-up statement

815 
WGUS74 KFWD 190025
FFSFWD

Flash Flood Statement
National Weather Service Fort Worth TX
725 PM CDT Wed Aug 18 2021

TXC425-190035-
/O.EXP.KFWD.FF.W.0023.000000T0000Z-210819T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Somervell TX-
725 PM CDT Wed Aug 18 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 730 PM CDT THIS EVENING FOR 
CENTRAL SOMERVELL COUNTY...

New flooding is no longer expected to pose a threat and the heaviest 
rainfall has ended. However, earlier rainfall may continue to run 
off and cause flooding of streams and creeks as well as other low 
lying and poor drainage areas. Please continue to heed any remaining 
road closures.

A Flash Flood Watch remains in effect until 1000 PM CDT for parts of 
north Texas.

LAT...LON 3229 9773 3231 9768 3224 9764 3222 9768
      3212 9788 3221 9793

$$

Stalley

The office that day

Everything else NWS Fort Worth, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 17, 7:48 PM CDT	Flash Flood Watch	FWD	Collin, Comanche, Cooke, Dallas, Delta, Denton and 23 more	26 hr
Aug 18, 3:16 AM CDT	Areal Flood Advisory	FWD	Kaufman	104 min
Aug 18, 4:08 AM CDT	Areal Flood Advisory	FWD	Henderson, Van Zandt	112 min
Aug 18, 6:40 AM CDT	Areal Flood Advisory	FWD	Jack, Montague, Wise	2 hr
Aug 18, 7:55 AM CDT	Areal Flood Advisory	FWD	Eastland, Stephens	3 hr
Aug 18, 8:18 AM CDT	Areal Flood Advisory	FWD	Jack, Palo Pinto	3 hr
Aug 18, 9:14 AM CDT	Areal Flood Advisory	FWD	Jack, Montague, Wise	3 hr
Aug 18, 9:40 AM CDT	Flash Flood Warning	FWD	Wise	2 hr
Aug 18, 9:55 AM CDT	Flash Flood Warning	FWD	Eastland, Palo Pinto	3 hr
Aug 18, 10:42 AM CDT	Areal Flood Advisory	FWD	Palo Pinto, Parker, Wise	2 hr
Aug 18, 10:49 AM CDT	Areal Flood Advisory	FWD	Wise	116 min
Aug 18, 10:56 AM CDT	Areal Flood Advisory	FWD	Dallas, Denton, Tarrant	2 hr
Aug 18, 11:50 AM CDT	Areal Flood Advisory	FWD	Collin, Dallas, Denton	3 hr
Aug 18, 1:05 PM CDT	Areal Flood Advisory	FWD	Dallas, Denton, Parker, Tarrant, Wise	115 min
Aug 18, 1:56 PM CDT	River Flood Warning	FWD	Hunt	8 hr
Aug 18, 2:57 PM CDT	Special Weather Statement	FWD	Anderson	33 min
Aug 18, 3:51 PM CDT	Special Weather Statement	FWD	Freestone	39 min
Aug 18, 5:11 PM CDT	Areal Flood Advisory	FWD	McLennan	2 hr
Aug 18, 6:39 PM CDT	Areal Flood Advisory	FWD	Bosque, Somervell	3 hr

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.