Alert archive / Alabama / Mesoscale Discussions in 2019

Mesoscale Discussion 270

April 6, 201920 counties in Alabama; 10 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2019, 7:09 PM CDT for 20 counties in Alabama; 10 counties in Mississippi. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Apr 6, 2019, 7:09 PM CDT (00:09 UTC)
Expired: Apr 6, 2019, 8:45 PM CDT
In force: 96 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 30 counties

Bibb County, AL, Blount County, AL, Chilton County, AL, Cullman County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Marion County, AL, Marshall County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Chickasaw County, MS, Clay County, MS, Itawamba County, MS, Kemper County, MS, Lowndes County, MS, Monroe County, MS, Neshoba County, MS, Noxubee County, MS, Oktibbeha County, MS, Winston County, MS

The radar

The Columbus AFB radar (KGWX), 76 km from the middle of the area, began a volume at 00:08 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 00:00Z, 0.2 hours before the alert went out and 89 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: 1407 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 889 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 61 m²/s²
0-3 km storm-relative helicity: 142 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.6

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.

Issued	Product	Office	Counties	Lasted
Apr 7, 1:13 PM CDT	Mesoscale Discussion	SPC	Colbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 4 more	2 hr
Apr 7, 5:36 PM CDT	Mesoscale Discussion	SPC	Blount, Calhoun, Cherokee, Cleburne, Cullman, DeKalb and 17 more	114 min
Apr 7, 5:29 AM CDT	Mesoscale Discussion	SPC	Bolivar, Coahoma, DeSoto, Quitman, Tate, Tunica	2 hr
Apr 7, 10:45 AM CDT	Mesoscale Discussion	SPC	Bolivar, Calhoun, Carroll, Chickasaw, Choctaw, Coahoma and 13 more	60 min
Apr 7, 3:41 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Amite, Attala, Bolivar, Carroll, Claiborne and 17 more	6 hr
Apr 7, 6:44 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Claiborne, Copiah, Franklin, Hinds and 15 more	2 hr

Nearby

Mesoscale Discussions in Alabama, 2019 Mesoscale Discussions in Mississippi, 2019 Every mesoscale discussion in 2019

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.