Alert archive / Florida / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 57, NWS Jacksonville, FL

May 18, 2013Nassau County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at May 18, 2013, 4:57 PM EDT for Nassau County, Florida. It was in force for 33 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: May 18, 2013, 4:57 PM EDT (20:57 UTC)
Expired: May 18, 2013, 5:30 PM EDT
In force: 33 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon

County Nassau County, FL

The radar

The Jacksonville radar (KJAX), 16 km from the middle of the area, began a volume at 20:56 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, 9.0 hours before the alert went out and 243 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: 3 J/kg
Mixed-layer CIN: -465 J/kg
Mixed-layer LCL: 1119 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 106 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 May 18, 2:24 PM EDT, 2 hours 33 minutes earlier.

Area forecast discussion, May 18, 2:24 PM EDT, 2 hours 33 minutes before

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Hazardous weather outlook, May 18, 3:24 AM EDT, 13 hours 33 minutes before

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In the hours before

Special weather statement, May 18, 4:33 PM EDT, 24 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
May 18, 4:33 PM EDT	Special Weather Statement	JAX	Nassau	42 min
May 18, 5:31 PM EDT	Severe Thunderstorm Warning	JAX	Nassau	29 min
May 18, 5:49 PM EDT	Special Weather Statement	JAX	Duval	26 min
May 18, 6:39 PM EDT	Special Weather Statement	JAX	Brantley	51 min

Nearby

Severe Thunderstorm Warnings in Florida, 2013 Every severe thunderstorm warning in 2013

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.