Alert archive / Florida / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 56, NWS Jacksonville, FL

May 11, 2013Saint Johns County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at May 11, 2013, 4:28 PM EDT for Saint Johns County, Florida. It was in force for 32 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 11, 2013, 4:28 PM EDT (20:28 UTC)
Expired
May 11, 2013, 5:00 PM EDT
In force
32 min
Issued by
NWS Jacksonville, FL
Area
Storm-based polygon

County Saint Johns County, FL

The radar

The Jacksonville radar (KJAX), 70 km from the middle of the area, began a volume at 20:32 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

Tampa Bay, FL (KTBW), launched 12:00Z, 8.5 hours before the alert went out and 264 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-pSkew-T log-p diagram, Tampa Bay, FL at 12:00Z on 2013-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1790 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tampa Bay, FL at 12:00Z on 2013-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 101 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1790 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
479 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
101 m²/s²
0-3 km storm-relative helicity
197 m²/s²
Significant tornado parameter
0.7
Supercell composite
4.3

Open this sounding in Storm Lab

The office that day

Everything else NWS Jacksonville, FL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 4:18 PM EDTSpecial Weather StatementJAXSaint Johns42 min
May 11, 4:26 PM EDTSpecial Marine WarningJAX64 min
May 11, 4:32 PM EDTSpecial Weather StatementJAXSaint Johns28 min
May 11, 6:16 PM EDTSpecial Weather StatementJAXMarion44 min
May 11, 6:27 PM EDTSpecial Marine WarningJAX2 hr
May 11, 7:08 PM EDTSpecial Weather StatementJAXDuval22 min
May 11, 7:35 PM EDTSpecial Weather StatementJAXFlagler40 min
May 11, 10:40 AM EDTRiver Flood WarningJAXAppling, Toombs7 days

Nearby

Severe Thunderstorm Warnings in Florida, 2013Every 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.