Alert archive / Florida / Flash Flood Warnings in 2021

Flash Flood Warning 40, NWS Tallahassee, FL

October 4, 2021Walton County, Florida

NWS Tallahassee, FL issued this flash flood warning at Oct 4, 2021, 5:38 AM CDT for Walton County, Florida. 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: Oct 4, 2021, 5:38 AM CDT (10:38 UTC)
Expired: Oct 4, 2021, 8:45 AM CDT
In force: 3 hr
Issued by: NWS Tallahassee, FL
Area: Storm-based polygon
Flood severity: None

County Walton County, FL

The radar

The Eglin Afb radar (KEVX), 40 km from the middle of the area, began a volume at 10:41 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

Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 10.6 hours before the alert went out and 195 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: 218 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 930 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -57 m²/s²
0-3 km storm-relative helicity: -61 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

746 
WGUS52 KTAE 041038
FFWTAE
FLC131-041345-
/O.NEW.KTAE.FF.W.0040.211004T1038Z-211004T1345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tallahassee FL
538 AM CDT Mon Oct 4 2021

The National Weather Service in Tallahassee has issued a

* Flash Flood Warning for...
  Walton County in the panhandle of Florida...

* Until 845 AM CDT.

* At 538 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 3 and 5 inches of rain 
  have fallen in the last 3 Hours. Additional rainfall amounts up to 
  1 inch are possible in the warned area. Flash flooding is ongoing 
  or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash 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...
  Eglin Air Force Base and Villa Tasso.

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.

&&

LAT...LON 3046 8639 3056 8639 3053 8625 3049 8625
      3049 8626 3047 8630 3048 8633 3047 8636
      3046 8637

FLASH FLOOD...RADAR INDICATED

$$

The office that day

Everything else NWS Tallahassee, FL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 4, 2:47 AM CDT	Flash Flood Watch	TAE	Bay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 5 more	4 days
Oct 4, 4:45 AM CDT	Areal Flood Advisory	TAE	Walton	3 hr
Oct 4, 6:04 AM CDT	Flash Flood Warning	TAE	Walton	12 hr
Oct 4, 7:52 AM CDT	Areal Flood Advisory	TAE	Walton	5 hr

Nearby

Flash Flood Warnings in Florida, 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.