Alert archive / Florida / Flash Flood Warnings in 2024

Flash Flood Warning 11, NWS Jacksonville, FL

August 23, 2024Saint Johns County, Florida

NWS Jacksonville, FL issued this flash flood warning at Aug 23, 2024, 11:05 PM EDT for Saint Johns County, Florida. It was in force for 85 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 23, 2024, 11:05 PM EDT (03:05 UTC)
Expired: Aug 24, 2024, 12:30 AM EDT
In force: 85 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
Flood severity: None

County Saint Johns County, FL

The radar

The Jacksonville radar (KJAX), 70 km from the middle of the area, began a volume at 03:07 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

Jacksonville, FL (KJAX), launched 00:00Z, 3.1 hours before the alert went out and 71 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: 733 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 599 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -32 m²/s²
0-3 km storm-relative helicity: -6 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Jacksonville, FL wrote its last area forecast discussion before this flash flood warning went out at Aug 23, 8:18 PM EDT, 2 hours 47 minutes earlier.

Area forecast discussion, Aug 23, 8:18 PM EDT, 2 hours 47 minutes before

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In the hours before

Special weather statement, Aug 23, 5:18 PM EDT, 5 hours 47 minutes before

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Local storm report, Aug 23, 5:34 PM EDT, 5 hours 31 minutes before

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Special weather statement, Aug 23, 5:50 PM EDT, 5 hours 15 minutes before

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Special weather statement, Aug 23, 6:08 PM EDT, 4 hours 57 minutes before

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Local storm report, Aug 23, 6:40 PM EDT, 4 hours 25 minutes before

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Special weather statement, Aug 23, 6:46 PM EDT, 4 hours 19 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 23, 10:05 PM EDT	Areal Flood Advisory	JAX	Duval, Saint Johns	115 min
Aug 23, 10:27 PM EDT	Areal Flood Advisory	JAX	Flagler, Saint Johns	2 hr
Aug 23, 10:52 PM EDT	Areal Flood Warning	JAX	Saint Johns	113 min
Aug 23, 10:55 PM EDT	Areal Flood Advisory	JAX	Duval	2 hr
Aug 23, 11:16 PM EDT	Flash Flood Warning	JAX	Duval, Saint Johns	89 min
Aug 23, 11:31 PM EDT	Areal Flood Warning	JAX	Flagler, Saint Johns	119 min
Aug 23, 11:43 PM EDT	Areal Flood Advisory	JAX	Nassau	2 hr
Aug 24, 12:30 AM EDT	Areal Flood Advisory	JAX	Duval, Nassau	2 hr
Aug 24, 1:42 AM EDT	Areal Flood Warning	JAX	Duval	3 hr
Aug 24, 2:40 AM EDT	Areal Flood Advisory	JAX	Duval, Saint Johns	2 hr
Aug 24, 2:49 AM EDT	Flash Flood Warning	JAX	Duval	116 min
Aug 24, 4:47 AM EDT	Areal Flood Warning	JAX	Duval	4 hr
Aug 24, 6:21 AM EDT	Flood Watch	JAX	Duval, Nassau	60 hr
Aug 24, 7:10 PM EDT	Areal Flood Advisory	JAX	Marion	65 min

Nearby

Flash Flood Warnings in Florida, 2024 Every flash flood warning in 2024

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.