Alert archive / Florida / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 194, NWS Jacksonville, FL

August 10, 2020Duval County, Nassau County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Aug 10, 2020, 7:56 PM EDT for Duval County, Nassau County, Florida. It was in force for 49 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 10, 2020, 7:56 PM EDT (23:56 UTC)
Expired: Aug 10, 2020, 8:45 PM EDT
In force: 49 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 nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 11.9 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: 776 J/kg
Mixed-layer CIN: -61 J/kg
Mixed-layer LCL: 1103 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: 1 m²/s²
0-3 km storm-relative helicity: 18 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 10, 7:18 PM EDT, 38 minutes earlier.

Area forecast discussion, Aug 10, 7:18 PM EDT, 38 minutes before

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In the hours before

Special weather statement, Aug 10, 6:41 PM EDT, 1 hour 15 minutes before

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Special weather statement, Aug 10, 7:05 PM EDT, 51 minutes before

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Special weather statement, Aug 10, 7:30 PM EDT, 26 minutes before

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Special weather statement, Aug 10, 7:38 PM EDT, 18 minutes before

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Special weather statement, Aug 10, 7:40 PM EDT, 16 minutes before

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Local storm report, Aug 10, 7:42 PM EDT, 14 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 9, 8:12 PM EDT	Severe Thunderstorm Warning	JAX	Nassau	48 min
Aug 9, 8:24 PM EDT	Special Marine Warning	JAX		96 min
Aug 9, 8:28 PM EDT	Special Weather Statement	JAX	Nassau	32 min
Aug 9, 8:31 PM EDT	Special Weather Statement	JAX	Hamilton	44 min
Aug 9, 8:44 PM EDT	Severe Thunderstorm Warning	JAX	Duval, Nassau	46 min
Aug 9, 8:58 PM EDT	Special Weather Statement	JAX	Baker	47 min
Aug 9, 9:08 PM EDT	Special Marine Warning	JAX		97 min
Aug 9, 9:20 PM EDT	Special Weather Statement	JAX	Duval	40 min
Aug 9, 9:51 PM EDT	Special Weather Statement	JAX	Baker	39 min
Aug 9, 9:53 PM EDT	Special Marine Warning	JAX		52 min
Aug 9, 9:58 PM EDT	Special Weather Statement	JAX	Duval	47 min
Aug 10, 9:49 AM EDT	River Flood Warning	JAX	Baker, Nassau	9 days
Aug 10, 4:46 PM EDT	Special Weather Statement	JAX	Alachua	29 min
Aug 10, 5:59 PM EDT	Special Weather Statement	JAX	Putnam	31 min
Aug 10, 6:16 PM EDT	Special Weather Statement	JAX	Hamilton	29 min
Aug 10, 6:26 PM EDT	Special Weather Statement	JAX	Suwannee	34 min
Aug 10, 6:41 PM EDT	Special Weather Statement	JAX	Columbia	19 min
Aug 10, 7:05 PM EDT	Special Weather Statement	JAX	Clay	25 min
Aug 10, 7:30 PM EDT	Special Weather Statement	JAX	Duval, Saint Johns	30 min
Aug 10, 7:38 PM EDT	Special Weather Statement	JAX	Saint Johns	22 min
Aug 10, 7:40 PM EDT	Special Weather Statement	JAX	Nassau	20 min
Aug 9, 8:00 PM EDT	Special Weather Statement	JAX	Charlton	30 min
Aug 9, 9:16 PM EDT	Special Weather Statement	JAX	Echols	44 min
Aug 10, 1:50 PM EDT	Special Weather Statement	JAX	Atkinson	25 min
Aug 10, 2:13 PM EDT	Special Weather Statement	JAX	Atkinson	47 min
Aug 10, 2:37 PM EDT	Special Weather Statement	JAX	Bacon	23 min
Aug 10, 3:00 PM EDT	Special Weather Statement	JAX	Ware	30 min
Aug 10, 3:03 PM EDT	Special Weather Statement	JAX	Bacon	27 min
Aug 10, 3:11 PM EDT	Special Weather Statement	JAX	Jeff Davis	34 min
Aug 10, 3:37 PM EDT	Special Weather Statement	JAX	Clinch, Ware	23 min
Aug 10, 4:13 PM EDT	Special Weather Statement	JAX	Wayne	32 min
Aug 10, 5:30 PM EDT	Special Weather Statement	JAX	Glynn	30 min

Nearby

Severe Thunderstorm Warnings in Florida, 2020 Every severe thunderstorm warning in 2020

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.