Alert archive / Florida / Mesoscale Discussions in 2018

Mesoscale Discussion 263

April 15, 20185 counties in Alabama; 7 counties in Florida; 7 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Apr 15, 2018, 1:45 AM CDT for 5 counties in Alabama; 7 counties in Florida; 7 counties in Georgia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 15, 2018, 1:45 AM CDT (06:45 UTC)
Expired
Apr 15, 2018, 3:45 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Coffee County, AL, Dale County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Bay County, FL, Calhoun County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Walton County, FL, Washington County, FL, Calhoun County, GA, Clay County, GA, Early County, GA, Miller County, GA, Quitman County, GA, Randolph County, GA, Seminole County, GA

The radar

The Eglin Afb radar (KEVX), 60 km from the middle of the area, began a volume at 06:48 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 00:00Z, 6.8 hours before the alert went out and 122 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 00:00Z on 2018-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2018-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1537 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
79 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 14, 9:27 PM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Conecuh, Covington, Crenshaw and 10 more93 min
Apr 14, 10:58 PM CDTTornado WatchSPCCoffee, Dale, Geneva, Henry, Houston8 hr
Apr 15, 5:42 AM CDTMesoscale DiscussionSPCBay, Calhoun, Gulf, Jackson93 min
Apr 15, 8:34 AM CDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Columbia, Gilchrist, Hamilton and 4 more86 min
Apr 15, 9:12 AM CDTTornado WatchSPCAlachua, Baker, Bradford, Citrus, Clay, Columbia and 22 more8 hr
Apr 15, 11:18 AM CDTMesoscale DiscussionSPCHardee, Hillsborough, Manatee, Polk57 min
Apr 15, 1:30 PM CDTMesoscale DiscussionSPCClay, Duval, Lake, Manatee, Polk, Putnam and 1 more90 min
Apr 15, 3:42 PM CDTMesoscale DiscussionSPCBroward, Collier, DeSoto, Glades, Hardee, Hendry and 4 more63 min
Apr 15, 11:13 AM CDTTornado WatchSPCBurke, Columbia, Lincoln, McDuffie, Richmond9 hr

Nearby

Mesoscale Discussions in Florida, 2018Mesoscale Discussions in Georgia, 2018Mesoscale Discussions in Alabama, 2018Every mesoscale discussion in 2018

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.