Alert archive / Mississippi / Mesoscale Discussions in 2018

Mesoscale Discussion 1679

December 1, 20188 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida; 15 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Dec 1, 2018, 4:31 AM CST for 8 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida; 15 counties in Mississippi. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued: Dec 1, 2018, 4:31 AM CST (10:31 UTC)
Expired: Dec 1, 2018, 5:30 AM CST
In force: 59 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

All 26 counties

Baldwin County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Escambia County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Clarke County, MS, Covington County, MS, Forrest County, MS, George County, MS, Greene County, MS, Harrison County, MS, Jackson County, MS, Jasper County, MS, Jones County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 56 km from the middle of the area, began a volume at 10:33 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

Jackson, MS (KJAN), launched 00:00Z, 10.5 hours before the alert went out and 219 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: 17 J/kg
Mixed-layer CIN: -174 J/kg
Mixed-layer LCL: 942 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 161 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Dec 1, 11:16 AM CST	Tornado Watch	SPC	Coffee, Covington, Dale, Escambia, Geneva, Henry and 1 more	7 hr
Dec 1, 1:35 PM CST	Mesoscale Discussion	SPC	Coffee, Covington, Dale, Geneva, Houston	85 min
Dec 1, 3:07 PM CST	Mesoscale Discussion	SPC	Autauga, Bibb, Chilton, Clay, Coosa, Dallas and 10 more	113 min
Dec 1, 3:38 PM CST	Mesoscale Discussion	SPC	Coffee, Covington, Dale, Geneva, Houston	97 min
Dec 1, 5:28 PM CST	Mesoscale Discussion	SPC	Colbert, Cullman, Fayette, Franklin, Lamar, Lauderdale and 7 more	62 min
Dec 1, 5:53 PM CST	Tornado Watch	SPC	Coffee, Covington, Dale, Geneva, Henry, Houston	9 hr
Dec 1, 10:45 AM CST	Mesoscale Discussion	SPC	Bay, Calhoun, Franklin, Gadsden, Gulf, Jackson and 4 more	2 hr
Dec 1, 12:58 AM CST	Mesoscale Discussion	SPC	Bolivar, Coahoma, Tunica, Washington	2 hr
Dec 1, 3:25 AM CST	Mesoscale Discussion	SPC	Bolivar, Coahoma, DeSoto, Leflore, Panola, Quitman and 5 more	2 hr

Nearby

Mesoscale Discussions in Mississippi, 2018 Mesoscale Discussions in Alabama, 2018 Mesoscale Discussions in Florida, 2018 Every mesoscale discussion in 2018

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.