Alert archive / Mississippi / Mesoscale Discussions in 2019

Mesoscale Discussion 99

February 12, 20199 counties in Alabama; 17 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Feb 12, 2019, 6:40 AM CST for 9 counties in Alabama; 17 counties in Mississippi. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Feb 12, 2019, 6:40 AM CST (12:40 UTC)
Expired: Feb 12, 2019, 9:15 AM CST
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 26 counties

Choctaw County, AL, Clarke County, AL, Greene County, AL, Hale County, AL, Marengo County, AL, Pickens County, AL, Sumter County, AL, Tuscaloosa County, AL, Washington County, AL, Clarke County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jasper County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Newton County, MS, Noxubee County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 122 km from the middle of the area, began a volume at 12:40 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

Slidell Radar S, LA (KSIL), launched 12:00Z, 0.7 hours before the alert went out and 190 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: 823 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 487 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 314 m²/s²
0-3 km storm-relative helicity: 329 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 7.6

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
Feb 12, 9:38 AM CST	Mesoscale Discussion	SPC	Autauga, Barbour, Bullock, Butler, Calhoun, Chambers and 27 more	2 hr

Nearby

Mesoscale Discussions in Mississippi, 2019 Mesoscale Discussions in Alabama, 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.