Alert archive / Alabama / Mesoscale Discussions in 2015

Mesoscale Discussion 1629

August 7, 201512 counties in Alabama; 5 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2015, 1:30 PM CDT for 12 counties in Alabama; 5 counties in Florida. It was in force for 45 min.

The area

The outline as issued.

The facts

Issued: Aug 7, 2015, 1:30 PM CDT (18:30 UTC)
Expired: Aug 7, 2015, 2:15 PM CDT
In force: 45 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Butler County, AL, Choctaw County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Escambia County, AL, Geneva County, AL, Marengo County, AL, Monroe County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL

The radar

The Mobile radar (KMOB), 117 km from the middle of the area, began a volume at 18:32 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

Birmingham, AL (KBMX), launched 12:00Z, 6.5 hours before the alert went out and 229 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: 1186 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 789 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 203 m²/s²
0-3 km storm-relative helicity: 255 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 6.3

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
Aug 6, 7:18 PM CDT	Mesoscale Discussion	SPC	Chambers, Lee, Macon, Russell	87 min
Aug 7, 8:39 AM CDT	Mesoscale Discussion	SPC	Lamar	66 min
Aug 7, 10:22 AM CDT	Severe Thunderstorm Watch	SPC	Bibb, Dallas, Fayette, Greene, Hale, Lamar and 6 more	4 hr

Nearby

Mesoscale Discussions in Alabama, 2015 Mesoscale Discussions in Florida, 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; radar from the NEXRAD Level II archive.