Alert archive / Texas / Flash Flood Warnings in 2020

Flash Flood Warning 21, NWS Fort Worth, TX

September 1, 20204 counties in Texas

NWS Fort Worth, TX issued this flash flood warning at Sep 1, 2020, 1:14 PM CDT for 4 counties in Texas. It was in force for 6 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 1, 2020, 1:14 PM CDT (18:14 UTC)
Expired
Sep 1, 2020, 7:15 PM CDT
In force
6 hr
Issued by
NWS Fort Worth, TX
Area
Storm-based polygon
Flood severity
None

Counties Collin County, TX, Cooke County, TX, Denton County, TX, Grayson County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 104 km from the middle of the area, began a volume at 18:14 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 1, 3:00 PM CDTFLASH FLOOD1 Wsw Denton, TXPHOTOS OF AT LEAST 1 FOOT OF WATER COVERING STREETS NEAR UNT IN SOUTHWEST DENTON. VEHICLES BECOMING STUCK ON FLOODED ROADS.

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

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 6.2 hours before the alert went out and 77 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, Fort Worth, TX at 12:00Z on 2020-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1346 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, Fort Worth, TX at 12:00Z on 2020-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 170 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
1346 J/kg
Mixed-layer CIN
-56 J/kg
Mixed-layer LCL
919 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
170 m²/s²
0-3 km storm-relative helicity
159 m²/s²
Significant tornado parameter
0.8
Supercell composite
7.9

Open this sounding in Storm Lab

The text

As transmitted.

159 
WGUS54 KFWD 011814
FFWFWD
TXC085-097-121-181-012115-
/O.NEW.KFWD.FF.W.0021.200901T1814Z-200901T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Fort Worth TX
114 PM CDT Tue Sep 1 2020

The National Weather Service in Fort Worth has issued a

* Flash Flood Warning for...
  Northwestern Collin County in north central Texas...
  Southeastern Cooke County in north central Texas...
  Northern Denton County in north central Texas...
  Southwestern Grayson County in north central Texas...

* Until 415 PM CDT.

* At 114 PM CDT, emergency management reported flooding due to 
  thunderstorms in Southwest Grayson County. Additional heavy rain 
  moving into areas that received between 2 and 4 inches of rain 
  earlier today will receive another 1 to 3 inches of rain shortly. 
  Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Emergency management and doppler 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...
  Denton, Sherman, Sanger, Whitesboro, Celina, Krum, Pilot Point, 
  Van Alstyne, Howe, Aubrey, Northlake, Krugerville, Collinsville, 
  Cross Roads, Gunter, Dorchester, Ray Roberts Park Isle Du Bois, 
  Ray Roberts Park Johnson Branch, Lake Kiowa and Oak Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 3367 9694 3367 9658 3340 9659 3340 9660
      3325 9684 3308 9739 3342 9738

FLASH FLOOD...OBSERVED

$$

Bonnette
2 follow-up statements
308 
WGUS54 KFWD 012056
FFWFWD
TXC085-097-121-181-020015-
/O.EXT.KFWD.FF.W.0021.000000T0000Z-200902T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Fort Worth TX
356 PM CDT Tue Sep 1 2020

The National Weather Service in Fort Worth has extended the

* Flash Flood Warning for...
  Northwestern Collin County in north central Texas...
  Southeastern Cooke County in north central Texas...
  Northern Denton County in north central Texas...
  Southwestern Grayson County in north central Texas...

* Until 715 PM CDT.

* At 356 PM CDT, emergency management in Grayson County reported 
  flooding due to thunderstorms producing heavy rain. Also, numerous 
  reports of flooded streets in the Denton area have been received. 
  Between 2 and 4 inches of rain have fallen with some isolated 
  amounts as high as 5 inches near Krum and Sanger.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Emergency management.

  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...
  Denton, Sherman, Sanger, Whitesboro, Celina, Krum, Pilot Point, 
  Van Alstyne, Howe, Aubrey, Northlake, Krugerville, Collinsville, 
  Cross Roads, Gunter, Dorchester, Ray Roberts Park Isle Du Bois, 
  Ray Roberts Park Johnson Branch, Lake Kiowa and Oak Point.

Additional rainfall amounts of up to 2 inches are possible in the 
warned area through 7 PM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets, and underpasses 
as well as other drainage areas and low lying spots.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 3367 9694 3367 9658 3340 9659 3340 9660
      3325 9684 3308 9739 3342 9738

FLASH FLOOD...OBSERVED

$$

Stalley
064 
WGUS74 KFWD 020017
FFSFWD

Flash Flood Statement
National Weather Service Fort Worth TX
717 PM CDT Tue Sep 1 2020

TXC085-097-181-020027-
/O.EXP.KFWD.FF.W.0021.000000T0000Z-200902T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Collin TX-Cooke TX-Grayson TX-
717 PM CDT Tue Sep 1 2020

...FLASH FLOOD WARNING HAS EXPIRED FOR NORTHWESTERN COLLIN, 
SOUTHEASTERN COOKE, NORTHERN DENTON AND SOUTHWESTERN GRAYSON 
COUNTIES...

The heaviest rain has ended, but nuisance flooding of low lying 
and/or poor drainage areas may continue for a few hours until the 
water has had a chance to recede. Please continue to avoid flooded 
areas and heed all road closures.

A Flash Flood Watch remains in effect until 700 AM CDT Thursday for 
the area.

LAT...LON 3367 9694 3367 9658 3340 9659 3340 9660
      3325 9684 3308 9739 3342 9738

$$

Stalley

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 31, 7:06 PM CDTFlash Flood WatchFWDBell, Bosque, Collin, Comanche, Cooke, Coryell and 37 more60 hr
Sep 1, 9:02 AM CDTAreal Flood AdvisoryFWDCooke, Fannin, Grayson, Montague3 hr
Sep 1, 11:23 AM CDTAreal Flood AdvisoryFWDCollin, Denton, Wise6 hr
Sep 1, 12:04 PM CDTAreal Flood AdvisoryFWDCooke, Grayson3 hr
Sep 1, 2:22 PM CDTSpecial Weather StatementFWDParker38 min
Sep 1, 2:36 PM CDTSpecial Weather StatementFWDEastland39 min
Sep 1, 2:50 PM CDTSpecial Weather StatementFWDYoung40 min
Sep 1, 2:58 PM CDTSevere Thunderstorm WarningFWDJack62 min
Sep 1, 3:03 PM CDTTornado WarningFWDJack25 min
Sep 1, 3:15 PM CDTSevere Thunderstorm WarningFWDJack, Palo Pinto, Young60 min
Sep 1, 3:33 PM CDTSevere Thunderstorm WarningFWDStephens, Young57 min
Sep 1, 3:54 PM CDTSevere Thunderstorm WarningFWDStephens36 min
Sep 1, 4:32 PM CDTAreal Flood AdvisoryFWDJack, Palo Pinto, Parker3 hr
Sep 1, 4:49 PM CDTFlash Flood WarningFWDDenton2 hr
Sep 1, 4:54 PM CDTRiver Flood WarningFWDDenton43 hr
Sep 1, 5:23 PM CDTAreal Flood AdvisoryFWDWise3 hr
Sep 1, 5:40 PM CDTSpecial Weather StatementFWDSomervell50 min
Sep 1, 6:05 PM CDTAreal Flood AdvisoryFWDTarrant3 hr
Sep 1, 6:19 PM CDTSpecial Weather StatementFWDJohnson56 min
Sep 1, 6:25 PM CDTSpecial Weather StatementFWDDallas65 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.