Alert archive / Florida / Mesoscale Discussions in 2015

Mesoscale Discussion 453

April 25, 201511 counties in Florida; 9 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2015, 12:20 PM EDT for 11 counties in Florida; 9 counties in Georgia. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Apr 25, 2015, 12:20 PM EDT (16:20 UTC)
Expired: Apr 25, 2015, 1:45 PM EDT
In force: 85 min
Issued by: the Storm Prediction Center

Counties Columbia County, FL, Gadsden County, FL, Hamilton County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Suwannee County, FL, Taylor County, FL, Wakulla County, FL, Brooks County, GA, Clinch County, GA, Decatur County, GA, Echols County, GA, Grady County, GA, Lanier County, GA, Lowndes County, GA, Thomas County, GA, Ware County, GA

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 114Apr 25, 4:05 PM EDT

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 4.3 hours before the alert went out and 81 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: 215 J/kg
Mixed-layer CIN: -111 J/kg
Mixed-layer LCL: 704 m above ground
0-6 km bulk shear: 61 kt
0-1 km storm-relative helicity: 304 m²/s²
0-3 km storm-relative helicity: 365 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

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.

Issued	Product	Office	Counties	Lasted
Apr 25, 5:12 AM EDT	Mesoscale Discussion	SPC	Escambia, Santa Rosa	63 min
Apr 25, 6:00 AM EDT	Tornado Watch	SPC	Bay, Escambia, Holmes, Jackson, Okaloosa, Santa Rosa and 2 more	7 hr
Apr 25, 8:41 AM EDT	Mesoscale Discussion	SPC	Bay, Calhoun, Gadsden, Holmes, Jackson, Jefferson and 8 more	94 min
Apr 25, 9:08 AM EDT	Tornado Watch	SPC	Baker, Calhoun, Columbia, Duval, Franklin, Gadsden and 11 more	7 hr
Apr 25, 2:36 PM EDT	Severe Thunderstorm Watch	SPC	Escambia, Okaloosa, Santa Rosa	4 hr
Apr 25, 2:50 PM EDT	Mesoscale Discussion	SPC	Escambia, Okaloosa, Santa Rosa	85 min
Apr 25, 3:30 PM EDT	Mesoscale Discussion	SPC	Baker, Columbia, Duval, Gadsden, Hamilton, Jefferson and 5 more	60 min
Apr 25, 4:07 PM EDT	Severe Thunderstorm Watch	SPC	Bay, Calhoun, Columbia, Franklin, Gadsden, Gulf and 13 more	7 hr
Apr 25, 7:19 PM EDT	Mesoscale Discussion	SPC	Calhoun, Franklin, Gadsden, Gulf, Hamilton, Jackson and 6 more	56 min
Apr 25, 3:10 PM EDT	Mesoscale Discussion	SPC	Carroll, Chattahoochee, Coweta, Haralson, Harris, Heard and 2 more	95 min
Apr 25, 5:38 PM EDT	Severe Thunderstorm Watch	SPC	Baldwin, Bibb, Bleckley, Butts, Chattahoochee, Clayton and 46 more	5 hr
Apr 25, 6:07 PM EDT	Mesoscale Discussion	SPC	Bryan, Bulloch, Burke, Candler, Chatham, Effingham and 7 more	53 min
Apr 25, 6:28 PM EDT	Severe Thunderstorm Watch	SPC	Bryan, Bulloch, Burke, Candler, Chatham, Effingham and 7 more	4 hr

Nearby

Mesoscale Discussions in Florida, 2015 Mesoscale Discussions in Georgia, 2015 Every mesoscale discussion in 2015

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.