Alert archive / Alabama / Mesoscale Discussions in 2014

Mesoscale Discussion 1987

December 23, 201438 counties in Alabama; 6 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Dec 23, 2014, 2:06 PM CST for 38 counties in Alabama; 6 counties in Florida. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: Dec 23, 2014, 2:06 PM CST (20:06 UTC)
Expired: Dec 23, 2014, 4:00 PM CST
In force: 114 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 44 counties

Autauga County, AL, Baldwin County, AL, Barbour County, AL, Bibb County, AL, Bullock County, AL, Butler County, AL, Chilton County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Coosa County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Geneva County, AL, Greene County, AL, Hale County, AL, Henry County, AL, Houston County, AL, Jefferson County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pickens County, AL, Pike County, AL, Shelby County, AL, Talladega County, AL, Tallapoosa County, AL, Tuscaloosa County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL

The radar

The Ft Rucker radar (KEOX), 122 km from the middle of the area, began a volume at 20:07 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 watches that followed

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

Tornado Watch 561Dec 23, 2:45 PM CST

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 8.1 hours before the alert went out and 167 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: 79 J/kg
Mixed-layer CIN: -65 J/kg
Mixed-layer LCL: 481 m above ground
0-6 km bulk shear: 67 kt
0-1 km storm-relative helicity: 147 m²/s²
0-3 km storm-relative helicity: 226 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

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
Dec 23, 3:45 AM CST	Mesoscale Discussion	SPC	Baldwin	2 hr
Dec 23, 7:39 AM CST	Mesoscale Discussion	SPC	Choctaw, Greene, Pickens, Sumter	3 hr
Dec 23, 7:40 AM CST	Mesoscale Discussion	SPC	Baldwin, Butler, Clarke, Coffee, Conecuh, Covington and 8 more	2 hr
Dec 23, 9:30 AM CST	Tornado Watch	SPC	Baldwin, Choctaw, Mobile, Washington	11 hr
Dec 23, 11:33 AM CST	Mesoscale Discussion	SPC	Choctaw, Greene, Mobile, Sumter, Washington	87 min
Dec 23, 2:47 PM CST	Tornado Watch	SPC	Autauga, Barbour, Bibb, Bullock, Butler, Chambers and 34 more	8 hr
Dec 23, 2:57 PM CST	Mesoscale Discussion	SPC	Choctaw, Greene, Mobile, Sumter, Washington	93 min
Dec 23, 4:59 PM CST	Mesoscale Discussion	SPC	Baldwin, Mobile, Washington	61 min
Dec 23, 12:12 PM CST	Mesoscale Discussion	SPC	Bay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 7 more	2 hr

Nearby

Mesoscale Discussions in Alabama, 2014 Mesoscale Discussions in Florida, 2014 Every mesoscale discussion in 2014

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.