Alert archive / Florida / Flash Flood Warnings in 2021

Flash Flood Warning 24, NWS Mobile, AL

May 11, 2021Okaloosa County, Florida

NWS Mobile, AL issued this flash flood warning at May 11, 2021, 4:09 PM CDT for Okaloosa 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: May 11, 2021, 4:09 PM CDT (21:09 UTC)
Expired: May 11, 2021, 6:53 PM CDT
In force: 3 hr
Issued by: NWS Mobile, AL
Area: Storm-based polygon
Flood severity: None

County Okaloosa County, FL

The radar

The Eglin Afb radar (KEVX), 59 km from the middle of the area, began a volume at 21:09 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 12:00Z, 9.2 hours before the alert went out and 216 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: 799 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 866 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 85 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.1

Open this sounding in Storm Lab

The text

As transmitted.

589 
WGUS54 KMOB 112109
FFWMOB
FLC091-120315-
/O.NEW.KMOB.FF.W.0024.210511T2109Z-210512T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mobile AL
409 PM CDT Tue May 11 2021

The National Weather Service in Mobile has issued a

* Flash Flood Warning for...
  East Central Okaloosa County in northwestern Florida...

* Until 1015 PM CDT Tuesday.

* At 409 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3.25 inches of 
  rain have fallen. The expected rainfall rate is 3.25 inches in 1 
  hour. Additional rainfall amounts of 1 to 2 inches 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...
  mainly rural areas of East Central Okaloosa County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3066 8662 3072 8655 3075 8639 3062 8639
      3061 8660

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...3.25 INCHES IN 1 HOUR

$$

1 follow-up statement

192 
WGUS74 KMOB 112353
FFSMOB

Flash Flood Statement
National Weather Service Mobile AL
653 PM CDT Tue May 11 2021

FLC091-120003-
/O.CAN.KMOB.FF.W.0024.000000T0000Z-210512T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Okaloosa FL-
653 PM CDT Tue May 11 2021

...FLASH FLOOD WARNING IS CANCELLED FOR EAST CENTRAL OKALOOSA 
COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3066 8662 3072 8655 3075 8639 3062 8639
      3061 8660

$$

CGAL

The office that day

Everything else NWS Mobile, AL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 11, 3:22 AM CDT	Flash Flood Watch	MOB	Escambia, Santa Rosa	36 hr
May 11, 1:29 PM CDT	Special Weather Statement	MOB	Escambia	46 min
May 11, 2:14 PM CDT	Special Weather Statement	MOB	Escambia	46 min
May 11, 2:36 PM CDT	Areal Flood Advisory	MOB	Escambia, Okaloosa, Santa Rosa	3 hr
May 11, 2:51 PM CDT	Special Weather Statement	MOB	Santa Rosa	39 min
May 11, 3:31 PM CDT	Special Weather Statement	MOB	Okaloosa	59 min
May 11, 3:58 PM CDT	Areal Flood Advisory	MOB	Okaloosa, Santa Rosa	3 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.