Alert archive / Florida / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 154, NWS Jacksonville, FL

July 20, 2007Marion County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Jul 20, 2007, 2:05 PM EDT for Marion County, Florida. It was in force for 55 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: Jul 20, 2007, 2:05 PM EDT (18:05 UTC)
Expired: Jul 20, 2007, 3:00 PM EDT
In force: 55 min
Issued by: NWS Jacksonville, FL
Area: Counties, with a storm outline in the text

County Marion County, FL

The radar

The Jacksonville radar (KJAX), 146 km from the middle of the area, began a volume at 18:05 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

Jacksonville, FL (KJAX), launched 12:00Z, 6.1 hours before the alert went out and 148 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: 1746 J/kg
Mixed-layer CIN: -61 J/kg
Mixed-layer LCL: 1145 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 61 m²/s²
0-3 km storm-relative helicity: 101 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 Jul 20, 8:30 AM EDT, 5 hours 35 minutes earlier.

Area forecast discussion, Jul 20, 8:30 AM EDT, 5 hours 35 minutes before

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Hazardous weather outlook, Jul 20, 2:03 PM EDT, 2 minutes before

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In the hours before

Special weather statement, Jul 20, 1:18 PM EDT, 47 minutes before

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Special weather statement, Jul 20, 2:02 PM EDT, 3 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
Jul 19, 9:02 PM EDT	Special Marine Warning	JAX		118 min
Jul 19, 10:47 PM EDT	Special Marine Warning	JAX		88 min
Jul 20, 2:59 PM EDT	Special Marine Warning	JAX		2 hr
Jul 20, 4:51 PM EDT	Special Marine Warning	JAX		114 min
Jul 20, 5:03 PM EDT	Severe Thunderstorm Warning	JAX	Flagler	42 min
Jul 20, 5:11 PM EDT	Severe Thunderstorm Warning	JAX	Saint Johns	49 min
Jul 20, 6:32 PM EDT	Severe Thunderstorm Warning	JAX	Duval	43 min
Jul 20, 6:47 PM EDT	Special Marine Warning	JAX		118 min
Jul 20, 7:34 PM EDT	Special Marine Warning	JAX		116 min
Jul 20, 5:32 PM EDT	Severe Thunderstorm Warning	JAX	Coffee, Jeff Davis	43 min
Jul 20, 6:19 PM EDT	Severe Thunderstorm Warning	JAX	Wayne	42 min
Jul 20, 6:29 PM EDT	Severe Thunderstorm Warning	JAX	Bacon, Pierce	61 min
Jul 20, 7:14 PM EDT	Severe Thunderstorm Warning	JAX	Charlton	38 min

Nearby

Severe Thunderstorm Warnings in Florida, 2007 Every severe thunderstorm warning in 2007

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.