Alert archive / Florida / Flash Flood Warnings in 2021

Flash Flood Warning 18, NWS Mobile, AL

April 24, 2021Okaloosa County, Florida

NWS Mobile, AL issued this flash flood warning at Apr 24, 2021, 10:19 AM CDT for Okaloosa County, Florida. It was in force for 4 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: Apr 24, 2021, 10:19 AM CDT (15:19 UTC)
Expired: Apr 24, 2021, 2:15 PM CDT
In force: 4 hr
Issued by: NWS Mobile, AL
Area: Storm-based polygon
Flood severity: None

County Okaloosa County, FL

The radar

The Eglin Afb radar (KEVX), 66 km from the middle of the area, began a volume at 15:22 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
Apr 24, 11:17 AM CDT	FLASH FLOOD	2 Wsw Crestview Airport, FL	FLASH FLOODING OCCURING ON VALLEY RD FROM HWY 90 TO STILLWILL BLVD. ROAD IS CLOSED DUE TO WATER.
Apr 24, 11:32 AM CDT	FLASH FLOOD	4 S Crestview, FL	WATER COVERING ROADWAYS AT THE INTERSECTION OF ANTIOCH RD AND ASHLEY RD. ROAD IS CLOSED.

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

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 3.3 hours before the alert went out and 222 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: 175 J/kg
Mixed-layer CIN: -61 J/kg
Mixed-layer LCL: 544 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 447 m²/s²
0-3 km storm-relative helicity: 570 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

158 
WGUS54 KMOB 241519
FFWMOB
FLC091-241915-
/O.NEW.KMOB.FF.W.0018.210424T1519Z-210424T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mobile AL
1019 AM CDT Sat Apr 24 2021

The National Weather Service in Mobile has issued a

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

* Until 215 PM CDT.

* At 1019 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. The expected rainfall rate is 1 to 2 inches in 1 
  hour. Additional rainfall amounts of 1 to 3 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...
  Crestview, Baker, Silver Springs, Milligan, Auburn, Garden City, 
  Nubbin Ridge, Galliver, Cannon Town, Killingsworth Crossroads, 
  Campton, Deerland, Holt, Dorcas and Kellys Mill.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3068 8639 3064 8679 3080 8679 3085 8673
      3089 8639

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

Black

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 24, 5:09 AM CDT	Severe Thunderstorm Warning	MOB	Escambia, Santa Rosa	51 min
Apr 24, 5:14 AM CDT	Severe Thunderstorm Warning	MOB	Escambia	46 min
Apr 24, 5:51 AM CDT	Severe Thunderstorm Warning	MOB	Escambia, Okaloosa, Santa Rosa	54 min
Apr 24, 5:57 AM CDT	Severe Thunderstorm Warning	MOB	Escambia, Okaloosa, Santa Rosa	63 min
Apr 24, 6:20 AM CDT	Flash Flood Warning	MOB	Escambia	4 hr
Apr 24, 6:42 AM CDT	Severe Thunderstorm Warning	MOB	Escambia, Okaloosa, Santa Rosa	48 min
Apr 24, 6:58 AM CDT	Severe Thunderstorm Warning	MOB	Escambia, Okaloosa, Santa Rosa	47 min
Apr 24, 7:44 AM CDT	Severe Thunderstorm Warning	MOB	Okaloosa, Santa Rosa	46 min
Apr 24, 8:24 AM CDT	Areal Flood Advisory	MOB	Escambia, Okaloosa, Santa Rosa	111 min
Apr 24, 8:29 AM CDT	Severe Thunderstorm Warning	MOB	Okaloosa	16 min
Apr 24, 9:51 AM CDT	Special Weather Statement	MOB	Okaloosa	39 min
Apr 24, 10:01 AM CDT	Tornado Warning	MOB	Okaloosa	14 min
Apr 24, 10:14 AM CDT	Special Weather Statement	MOB	Okaloosa, Santa Rosa	46 min
Apr 24, 10:39 AM CDT	Severe Thunderstorm Warning	MOB	Okaloosa	36 min
Apr 24, 11:09 AM CDT	Special Weather Statement	MOB	Santa Rosa	51 min
Apr 24, 12:46 PM CDT	Severe Thunderstorm Warning	MOB	Okaloosa	44 min
Apr 24, 6:27 PM CDT	Severe Thunderstorm Warning	MOB	Escambia	48 min
Apr 24, 6:33 PM CDT	Areal Flood Warning	MOB	Escambia, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.