Alert archive / Florida / Flash Flood Warnings in 2024

Flash Flood Warning 26, NWS Jacksonville, FL

October 10, 2024Saint Johns County, Florida

NWS Jacksonville, FL issued this flash flood warning at Oct 10, 2024, 2:02 AM EDT for Saint Johns County, Florida. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Oct 10, 2024, 2:02 AM EDT (06:02 UTC)
Expired: Oct 10, 2024, 8:00 AM EDT
In force: 6 hr
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 06:04 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, 6.0 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: 179 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 530 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 103 m²/s²
0-3 km storm-relative helicity: -23 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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 Oct 9, 7:20 PM EDT, 6 hours 42 minutes earlier.

Area forecast discussion, Oct 9, 7:20 PM EDT, 6 hours 42 minutes before

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In the hours before

Local storm report, Oct 10, 1:37 AM EDT, 25 minutes before

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Local storm report, Oct 10, 1:40 AM EDT, 22 minutes before

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Local storm report, Oct 10, 1:53 AM EDT, 9 minutes before

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Local storm report, Oct 10, 1:57 AM EDT, 5 minutes before

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Local storm report, Oct 10, 1:59 AM EDT, 3 minutes before

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Local storm report, Oct 10, 2:02 AM EDT, 0 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
Oct 9, 9:00 PM EDT	River Flood Warning	JAX	Alachua, Union	5 days
Oct 9, 9:01 PM EDT	River Flood Warning	JAX	Alachua, Columbia	5 days
Oct 10, 3:16 AM EDT	Flash Flood Warning	JAX	Flagler, Marion, Putnam, Saint Johns	5 hr
Oct 10, 7:57 AM EDT	Areal Flood Warning	JAX	Saint Johns	5 hr
Oct 10, 8:00 AM EDT	Areal Flood Warning	JAX	Flagler, Marion, Putnam, Saint Johns	3 hr
Oct 10, 4:45 PM EDT	Wind Advisory	JAX	Duval, Flagler	5 hr
Oct 10, 4:55 PM EDT	Gale Warning	JAX		9 hr
Oct 10, 4:55 PM EDT	Small Craft Advisory	JAX		45 hr
Oct 10, 5:01 PM EDT	Coastal Flood Warning	JAX	Clay, Duval, Flagler, Putnam	5 days
Oct 10, 5:01 PM EDT	Coastal Flood Advisory	JAX	Clay, Duval, Flagler, Nassau, Putnam	9 days

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.