Alert archive / Florida / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 185, NWS Jacksonville, FL

August 8, 2018Duval County, Nassau County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Aug 8, 2018, 4:49 PM EDT for Duval County, Nassau County, Florida. It was in force for 20 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 8, 2018, 4:49 PM EDT (20:49 UTC)
Expired: Aug 8, 2018, 5:09 PM EDT
In force: 20 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Duval County, FL, Nassau County, FL

The radar

The Jacksonville radar (KJAX), 1 km from the middle of the area, began a volume at 20:49 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 8.8 hours before the alert went out and 248 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: 1898 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 860 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 32 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 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 Aug 8, 3:31 PM EDT, 1 hour 18 minutes earlier.

Area forecast discussion, Aug 8, 3:31 PM EDT, 1 hour 18 minutes before

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In the hours before

Special weather statement, Aug 8, 4:17 PM EDT, 32 minutes before

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Local storm report, Aug 8, 4:22 PM EDT, 27 minutes before

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Local storm report, Aug 8, 4:25 PM EDT, 24 minutes before

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Special weather statement, Aug 8, 4:25 PM EDT, 24 minutes before

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Special weather statement, Aug 8, 4:43 PM EDT, 6 minutes before

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Special weather statement, Aug 8, 4:45 PM EDT, 4 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 8, 3:16 PM EDT	Special Weather Statement	JAX	Hamilton	44 min
Aug 8, 3:19 PM EDT	Severe Thunderstorm Warning	JAX	Columbia, Hamilton, Suwannee	41 min
Aug 8, 4:01 PM EDT	Special Weather Statement	JAX	Bradford	44 min
Aug 8, 4:17 PM EDT	Special Weather Statement	JAX	Duval	43 min
Aug 8, 4:25 PM EDT	Special Weather Statement	JAX	Hamilton	50 min
Aug 8, 4:43 PM EDT	Special Weather Statement	JAX	Duval	47 min
Aug 8, 4:45 PM EDT	Special Weather Statement	JAX	Clay	45 min
Aug 8, 4:54 PM EDT	Special Weather Statement	JAX	Nassau	51 min
Aug 8, 5:33 PM EDT	Areal Flood Advisory	JAX	Baker, Duval, Nassau	87 min
Aug 8, 5:35 PM EDT	Special Marine Warning	JAX		55 min
Aug 8, 5:59 PM EDT	Special Marine Warning	JAX		61 min
Aug 8, 6:00 PM EDT	Special Weather Statement	JAX	Nassau	45 min
Aug 8, 7:14 PM EDT	Special Weather Statement	JAX	Putnam	46 min
Aug 8, 7:30 PM EDT	Areal Flood Advisory	JAX	Putnam	90 min
Aug 8, 5:04 PM EDT	Special Weather Statement	JAX	Charlton	41 min
Aug 8, 5:20 PM EDT	Special Weather Statement	JAX	Camden	40 min
Aug 8, 5:46 PM EDT	Special Weather Statement	JAX	Atkinson	44 min
Aug 8, 6:08 PM EDT	Severe Thunderstorm Warning	JAX	Atkinson, Clinch, Coffee, Ware	52 min
Aug 8, 6:16 PM EDT	Special Weather Statement	JAX	Ware	44 min
Aug 8, 6:32 PM EDT	Severe Thunderstorm Warning	JAX	Atkinson, Bacon, Coffee, Jeff Davis	43 min
Aug 8, 6:46 PM EDT	Areal Flood Advisory	JAX	Clinch, Ware	89 min
Aug 8, 6:49 PM EDT	Severe Thunderstorm Warning	JAX	Appling, Bacon, Brantley, Pierce, Ware, Wayne	41 min
Aug 8, 6:52 PM EDT	Areal Flood Advisory	JAX	Brantley	83 min
Aug 8, 6:58 PM EDT	Special Weather Statement	JAX	Bacon	47 min
Aug 8, 7:06 PM EDT	Areal Flood Warning	JAX	Brantley	84 min
Aug 8, 7:27 PM EDT	Special Weather Statement	JAX	Appling, Bacon, Pierce, Wayne	48 min

Nearby

Severe Thunderstorm Warnings in Florida, 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.