Alert archive / Florida / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 33, NWS Jacksonville, FL

April 15, 2018Nassau County, Florida; Camden County, Georgia

NWS Jacksonville, FL issued this severe thunderstorm warning at Apr 15, 2018, 3:14 PM EDT for Nassau County, Florida; Camden County, Georgia. It was in force for 46 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 15, 2018, 3:14 PM EDT (19:14 UTC)
Expired: Apr 15, 2018, 4:00 PM EDT
In force: 46 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Nassau County, FL, Camden County, GA

The radar

The Jacksonville radar (KJAX), 31 km from the middle of the area, began a volume at 19:14 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 15, 10:12 AM EDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 7.2 hours before the alert went out and 30 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: 651 J/kg
Mixed-layer CIN: -59 J/kg
Mixed-layer LCL: 809 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 147 m²/s²
0-3 km storm-relative helicity: 145 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.1

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 15, 2:57 PM EDT, 17 minutes earlier.

Area forecast discussion, Apr 15, 2:57 PM EDT, 17 minutes before

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In the hours before

Local storm report, Apr 15, 2:54 PM EDT, 20 minutes before

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Local storm report, Apr 15, 2:58 PM EDT, 16 minutes before

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Local storm report, Apr 15, 3:01 PM EDT, 13 minutes before

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Special weather statement, Apr 15, 3:09 PM EDT, 5 minutes before

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Local storm report, Apr 15, 3:10 PM EDT, 4 minutes before

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Local storm report, Apr 15, 3:13 PM EDT, 1 minute 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 15, 3:24 AM EDT	Wind Advisory	JAX	Baker, Bradford, Duval, Flagler, Gilchrist, Nassau and 2 more	13 hr
Apr 15, 9:57 AM EDT	Special Weather Statement	JAX	Hamilton, Suwannee	63 min
Apr 15, 10:09 AM EDT	Severe Thunderstorm Warning	JAX	Hamilton, Suwannee	66 min
Apr 15, 11:13 AM EDT	Severe Thunderstorm Warning	JAX	Columbia, Hamilton, Suwannee	47 min
Apr 15, 12:01 PM EDT	Severe Thunderstorm Warning	JAX	Baker, Columbia, Hamilton, Suwannee	44 min
Apr 15, 12:16 PM EDT	Special Weather Statement	JAX	Gilchrist	59 min
Apr 15, 12:45 PM EDT	Special Weather Statement	JAX	Columbia, Gilchrist	45 min
Apr 15, 1:16 PM EDT	Special Weather Statement	JAX	Marion	44 min
Apr 15, 1:21 PM EDT	Special Weather Statement	JAX	Alachua, Bradford, Union	39 min
Apr 15, 1:31 PM EDT	Special Weather Statement	JAX	Columbia, Gilchrist	44 min
Apr 15, 1:57 PM EDT	Special Weather Statement	JAX	Alachua, Bradford, Marion, Union	48 min
Apr 15, 2:07 PM EDT	Severe Thunderstorm Warning	JAX	Alachua, Clay, Marion, Putnam	53 min
Apr 15, 2:14 PM EDT	Special Weather Statement	JAX	Nassau	46 min
Apr 15, 2:15 PM EDT	Special Marine Warning	JAX		60 min
Apr 15, 2:16 PM EDT	Severe Thunderstorm Warning	JAX	Alachua, Baker, Bradford, Clay, Duval, Nassau	44 min
Apr 15, 2:23 PM EDT	Severe Thunderstorm Warning	JAX	Nassau	52 min
Apr 15, 2:40 PM EDT	Severe Thunderstorm Warning	JAX	Alachua, Bradford, Marion, Putnam	50 min
Apr 15, 2:45 PM EDT	Severe Thunderstorm Warning	JAX	Clay, Duval, Nassau, Saint Johns	45 min
Apr 15, 3:06 PM EDT	Special Marine Warning	JAX		84 min
Apr 15, 3:09 PM EDT	Special Weather Statement	JAX	Flagler, Saint Johns	66 min
Apr 15, 3:10 PM EDT	Special Marine Warning	JAX		2 hr
Apr 15, 3:22 PM EDT	Severe Thunderstorm Warning	JAX	Duval, Flagler, Nassau, Saint Johns	38 min
Apr 15, 3:40 PM EDT	Special Marine Warning	JAX		2 hr
Apr 15, 5:00 PM EDT	Special Marine Warning	JAX		45 min
Apr 15, 6:34 PM EDT	Special Marine Warning	JAX		41 min
Apr 15, 10:14 AM EDT	Severe Thunderstorm Warning	JAX	Atkinson, Coffee, Jeff Davis	61 min
Apr 15, 11:05 AM EDT	Special Weather Statement	JAX	Appling, Bacon, Jeff Davis	55 min
Apr 15, 11:15 AM EDT	Severe Thunderstorm Warning	JAX	Appling, Atkinson, Bacon, Coffee, Jeff Davis, Ware	45 min
Apr 15, 11:56 AM EDT	Severe Thunderstorm Warning	JAX	Appling, Bacon, Jeff Davis, Pierce, Wayne	49 min
Apr 15, 12:42 PM EDT	Special Weather Statement	JAX	Brantley, Charlton, Wayne	63 min
Apr 15, 1:38 PM EDT	Special Weather Statement	JAX	Brantley, Charlton	52 min
Apr 15, 2:15 PM EDT	Severe Thunderstorm Warning	JAX	Brantley, Glynn, Wayne	45 min
Apr 15, 2:34 PM EDT	Severe Thunderstorm Warning	JAX	Camden, Glynn	41 min
Apr 15, 2:54 PM EDT	Tornado Warning	JAX	Camden, Glynn	27 min
Apr 15, 3:23 PM EDT	Severe Thunderstorm Warning	JAX	Camden, Glynn	52 min

Nearby

Severe Thunderstorm Warnings in Florida, 2018 Severe Thunderstorm Warnings in Georgia, 2018 Every severe thunderstorm warning in 2018

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.