Alert archive / Florida / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 87, NWS Jacksonville, FL

June 30, 2019Saint Johns County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Jun 30, 2019, 6:43 PM EDT for Saint Johns County, Florida. It was in force for 24 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
Jun 30, 2019, 6:43 PM EDT (22:43 UTC)
Expired
Jun 30, 2019, 7:07 PM EDT
In force
24 min
Issued by
NWS Jacksonville, FL
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Saint Johns County, FL

The radar

The Jacksonville radar (KJAX), 70 km from the middle of the area, began a volume at 22:45 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

Cape Canaveral, FL (KXMR), launched 12:00Z, 10.7 hours before the alert went out and 183 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, Cape Canaveral, FL at 12:00Z on 2019-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 569 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, Cape Canaveral, FL at 12:00Z on 2019-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939Sfc1 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
569 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
928 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 5:52 PM EDTSpecial Weather StatementJAXDuval38 min
Jun 30, 6:08 PM EDTSpecial Marine WarningJAX67 min
Jun 30, 6:22 PM EDTSpecial Weather StatementJAXSaint Johns53 min
Jun 30, 6:24 PM EDTSpecial Marine WarningJAX66 min
Jun 30, 6:38 PM EDTSpecial Marine WarningJAX67 min
Jun 30, 6:47 PM EDTSpecial Weather StatementJAXNassau28 min
Jun 30, 6:55 PM EDTSpecial Weather StatementJAXMarion50 min
Jun 30, 7:28 PM EDTSpecial Weather StatementJAXMarion47 min
Jun 30, 7:38 PM EDTAreal Flood AdvisoryJAXAlachua, Marion2 hr

Nearby

Severe Thunderstorm Warnings in Florida, 2019Every severe thunderstorm warning in 2019

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.