Alert archive / Florida / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 95, NWS Jacksonville, FL

April 27, 2023Nassau County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Apr 27, 2023, 9:58 PM EDT for Nassau County, Florida. It was in force for 17 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: Apr 27, 2023, 9:58 PM EDT (01:58 UTC)
Expired: Apr 27, 2023, 10:15 PM EDT
In force: 17 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Nassau County, FL

The radar

The Jacksonville radar (KJAX), 16 km from the middle of the area, began a volume at 01:59 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 27, 2:46 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 00:00Z, 2.0 hours before the alert went out and 268 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: 1345 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 836 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 89 m²/s²
0-3 km storm-relative helicity: 166 m²/s²
Significant tornado parameter: 1.1
Supercell composite: 9.4

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Apr 27, 9:47 PM EDT, 11 minutes earlier.

Area forecast discussion, Apr 27, 9:47 PM EDT, 11 minutes before

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In the hours before

Local storm report, Apr 27, 9:10 PM EDT, 48 minutes before

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Special weather statement, Apr 27, 9:11 PM EDT, 47 minutes before

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Local storm report, Apr 27, 9:14 PM EDT, 44 minutes before

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Special weather statement, Apr 27, 9:15 PM EDT, 43 minutes before

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Special weather statement, Apr 27, 9:36 PM EDT, 22 minutes before

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Special weather statement, Apr 27, 9:49 PM EDT, 9 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
Apr 27, 8:29 PM EDT	Special Weather Statement	JAX	Alachua	46 min
Apr 27, 8:36 PM EDT	Special Weather Statement	JAX	Baker, Nassau	39 min
Apr 27, 8:57 PM EDT	Severe Thunderstorm Warning	JAX	Alachua, Bradford, Clay, Marion, Putnam	48 min
Apr 27, 9:11 PM EDT	Special Weather Statement	JAX	Duval, Nassau	49 min
Apr 27, 9:15 PM EDT	Special Weather Statement	JAX	Marion	30 min
Apr 27, 9:33 PM EDT	Special Marine Warning	JAX		87 min
Apr 27, 9:36 PM EDT	Special Weather Statement	JAX	Flagler, Putnam, Saint Johns	54 min
Apr 27, 9:49 PM EDT	Special Weather Statement	JAX	Duval	26 min
Apr 27, 10:07 PM EDT	Special Marine Warning	JAX		38 min
Apr 27, 10:09 PM EDT	Special Marine Warning	JAX		66 min
Apr 27, 10:30 PM EDT	Special Weather Statement	JAX	Flagler	15 min
Apr 27, 11:08 PM EDT	Special Marine Warning	JAX		76 min
Apr 27, 8:11 PM EDT	Special Weather Statement	JAX	Echols	34 min
Apr 28, 6:47 PM EDT	Special Weather Statement	JAX	Brantley	28 min
Apr 28, 7:11 PM EDT	Special Weather Statement	JAX	Ware	34 min
Apr 28, 7:13 PM EDT	Special Weather Statement	JAX	Brantley	47 min
Apr 28, 7:24 PM EDT	Special Weather Statement	JAX	Wayne	36 min
Apr 28, 7:36 PM EDT	Severe Thunderstorm Warning	JAX	Brantley, Wayne	39 min

Nearby

Severe Thunderstorm Warnings in Florida, 2023 Every severe thunderstorm warning in 2023

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.