Alert archive / Florida / Mesoscale Discussions in 2012

Mesoscale Discussion 799

May 13, 2012Okaloosa County, Santa Rosa County, Walton County, Florida

The Storm Prediction Center issued this mesoscale discussion at May 13, 2012, 7:20 AM CDT for Okaloosa County, Santa Rosa County, Walton County, Florida. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
May 13, 2012, 7:20 AM CDT (12:20 UTC)
Expired
May 13, 2012, 8:15 AM CDT
In force
55 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL

The radar

The Eglin Afb radar (KEVX), 59 km from the middle of the area, began a volume at 12:20 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, 0.3 hours before the alert went out and 213 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, Tallahassee Rgnl, FL at 12:00Z on 2012-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 155 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, Tallahassee Rgnl, FL at 12:00Z on 2012-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 136 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
155 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
760 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
136 m²/s²
0-3 km storm-relative helicity
205 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 13, 10:41 AM CDTMesoscale DiscussionSPCBay, Holmes, Walton, Washington2 hr

Nearby

Mesoscale Discussions in Florida, 2012Every mesoscale discussion in 2012

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.