Alert archive / Georgia / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 18, NWS Jacksonville, FL

February 6, 2020Nassau County, Florida; 4 counties in Georgia

NWS Jacksonville, FL issued this severe thunderstorm warning at Feb 6, 2020, 9:28 PM EST for Nassau County, Florida; 4 counties in Georgia. It was in force for 47 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: Feb 6, 2020, 9:28 PM EST (02:28 UTC)
Expired: Feb 6, 2020, 10:15 PM EST
In force: 47 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Nassau County, FL, Camden County, GA, Charlton County, GA, Glynn County, GA, Ware County, GA

The radar

The Jacksonville radar (KJAX), 51 km from the middle of the area, began a volume at 02:29 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
Feb 6, 5:30 PM EST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Jacksonville, FL (KJAX), launched 00:00Z, 2.5 hours before the alert went out and 50 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: 301 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 1234 m above ground
0-6 km bulk shear: 81 kt
0-1 km storm-relative helicity: 252 m²/s²
0-3 km storm-relative helicity: 344 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 1.9

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 Feb 6, 8:58 PM EST, 30 minutes earlier.

Area forecast discussion, Feb 6, 8:58 PM EST, 30 minutes before

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In the hours before

Local storm report, Feb 6, 8:43 PM EST, 45 minutes before

PRELIMINARY LOCAL STORM REPORT
National Weather Service Jacksonville FL
843 PM EST THU FEB 6 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0810 PM     TSTM WND DMG     5 SW ALMA               31.50N 82.54W
02/06/2020                   Bacon              GA   911 CALL CENTER

            BACON COUNTY 911/DISPATCH REPORTS TREES AND POWERLINES
            DOWNED COUNTY-WIDE.

&&

NELSON

Local storm report, Feb 6, 9:07 PM EST, 21 minutes before

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Local storm report, Feb 6, 9:15 PM EST, 13 minutes before

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Local storm report, Feb 6, 9:19 PM EST, 9 minutes before

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Local storm report, Feb 6, 9:20 PM EST, 8 minutes before

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Local storm report, Feb 6, 9:23 PM EST, 5 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
Feb 6, 7:04 PM EST	Severe Thunderstorm Warning	JAX	Hamilton, Suwannee	56 min
Feb 6, 7:42 PM EST	Severe Thunderstorm Warning	JAX	Baker, Columbia, Hamilton, Suwannee	63 min
Feb 6, 8:00 PM EST	Severe Thunderstorm Warning	JAX	Columbia, Hamilton, Suwannee	45 min
Feb 6, 8:41 PM EST	Severe Thunderstorm Warning	JAX	Alachua, Baker, Columbia, Gilchrist, Hamilton, Suwannee and 1 more	49 min
Feb 6, 8:51 PM EST	Tornado Warning	JAX	Baker, Columbia, Hamilton	39 min
Feb 6, 8:55 PM EST	Severe Thunderstorm Warning	JAX	Alachua, Gilchrist	50 min
Feb 6, 9:22 PM EST	Severe Thunderstorm Warning	JAX	Alachua, Baker, Bradford, Clay, Duval, Gilchrist and 3 more	38 min
Feb 6, 9:34 PM EST	Severe Thunderstorm Warning	JAX	Alachua, Marion	41 min
Feb 6, 9:43 PM EST	Special Marine Warning	JAX		2 hr
Feb 6, 9:54 PM EST	Severe Thunderstorm Warning	JAX	Nassau	51 min
Feb 6, 9:56 PM EST	Severe Thunderstorm Warning	JAX	Alachua, Bradford, Clay, Duval, Nassau, Putnam and 1 more	49 min
Feb 6, 10:00 PM EST	Special Marine Warning	JAX		2 hr
Feb 6, 10:11 PM EST	Severe Thunderstorm Warning	JAX	Alachua, Marion, Putnam	49 min
Feb 6, 10:42 PM EST	Severe Thunderstorm Warning	JAX	Clay, Duval, Nassau, Putnam, Saint Johns	48 min
Feb 6, 10:57 PM EST	Severe Thunderstorm Warning	JAX	Flagler, Marion, Putnam, Saint Johns	63 min
Feb 6, 11:45 PM EST	Special Marine Warning	JAX		30 min
Feb 6, 11:50 PM EST	Special Marine Warning	JAX		115 min
Feb 6, 11:59 PM EST	Severe Thunderstorm Warning	JAX	Flagler	16 min
Feb 7, 3:29 AM EST	Wind Advisory	JAX	Alachua, Baker, Bradford, Duval, Flagler, Gilchrist and 4 more	10 hr
Feb 7, 1:52 PM EST	Frost Advisory	JAX	Alachua, Baker, Bradford, Gilchrist, Marion, Nassau and 2 more	19 hr
Feb 7, 1:53 PM EST	Small Craft Advisory	JAX		7 hr
Feb 6, 7:09 PM EST	Severe Thunderstorm Warning	JAX	Appling, Jeff Davis	51 min
Feb 6, 7:16 PM EST	Severe Thunderstorm Warning	JAX	Appling, Bacon, Coffee, Jeff Davis	44 min
Feb 6, 7:18 PM EST	Severe Thunderstorm Warning	JAX	Clinch, Echols	57 min
Feb 6, 7:34 PM EST	Tornado Warning	JAX	Atkinson, Bacon, Clinch, Coffee, Pierce, Ware	26 min
Feb 6, 7:52 PM EST	Severe Thunderstorm Warning	JAX	Appling, Atkinson, Bacon, Clinch, Coffee, Jeff Davis and 3 more	38 min
Feb 6, 7:58 PM EST	Severe Thunderstorm Warning	JAX	Appling, Brantley, Charlton, Clinch, Glynn, Pierce and 2 more	47 min
Feb 6, 8:29 PM EST	Severe Thunderstorm Warning	JAX	Appling, Bacon, Pierce, Wayne	33 min
Feb 6, 8:45 PM EST	Severe Thunderstorm Warning	JAX	Brantley, Charlton, Clinch, Echols, Pierce, Ware	45 min
Feb 6, 9:07 PM EST	Severe Thunderstorm Warning	JAX	Brantley, Glynn, Pierce, Wayne	38 min
Feb 6, 9:18 PM EST	Severe Thunderstorm Warning	JAX	Brantley, Camden, Charlton, Glynn, Wayne	42 min

Nearby

Severe Thunderstorm Warnings in Georgia, 2020 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; radar from the NEXRAD Level II archive.