Alert archive / Alabama / Mesoscale Discussions in 2018

Mesoscale Discussion 259

April 14, 20188 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida; George County, Jackson County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 14, 2018, 6:17 PM CDT for 8 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida; George County, Jackson County, Mississippi. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: Apr 14, 2018, 6:17 PM CDT (23:17 UTC)
Expired: Apr 14, 2018, 8:15 PM CDT
In force: 118 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

Counties Baldwin County, AL, Butler County, AL, Clarke County, AL, Conecuh County, AL, Covington County, AL, Escambia County, AL, Mobile County, AL, Monroe County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, George County, MS, Jackson County, MS

The radar

The Mobile radar (KMOB), 51 km from the middle of the area, began a volume at 23:16 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 49Apr 14, 6:50 PM CDT

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 11.3 hours before the alert went out and 199 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: 1802 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 534 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 222 m²/s²
0-3 km storm-relative helicity: 293 m²/s²
Significant tornado parameter: 1.6
Supercell composite: 12.6

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 14, 4:35 AM CDT	Mesoscale Discussion	SPC	Colbert, Fayette, Franklin, Lamar, Lauderdale, Marion and 1 more	115 min
Apr 14, 6:37 AM CDT	Mesoscale Discussion	SPC	Sumter	83 min
Apr 14, 9:40 AM CDT	Mesoscale Discussion	SPC	Autauga, Baldwin, Bibb, Butler, Chilton, Choctaw and 18 more	95 min
Apr 14, 10:36 AM CDT	Tornado Watch	SPC	Autauga, Baldwin, Bibb, Blount, Butler, Chilton and 22 more	8 hr
Apr 14, 12:41 PM CDT	Mesoscale Discussion	SPC	Autauga, Baldwin, Bibb, Butler, Chilton, Choctaw and 18 more	94 min
Apr 14, 2:56 PM CDT	Mesoscale Discussion	SPC	Autauga, Chilton, Coosa, Dallas, Lowndes, Mobile and 5 more	94 min
Apr 14, 6:55 PM CDT	Tornado Watch	SPC	Baldwin, Butler, Clarke, Conecuh, Covington, Crenshaw and 7 more	6 hr
Apr 13, 7:22 PM CDT	Tornado Watch	SPC	Adams, Bolivar, Claiborne, Franklin, Issaquena, Jefferson and 4 more	3 hr
Apr 13, 10:12 PM CDT	Tornado Watch	SPC	Adams, Alcorn, Benton, Bolivar, Calhoun, Carroll and 33 more	10 hr
Apr 14, 2:10 AM CDT	Mesoscale Discussion	SPC	Adams, Attala, Benton, Bolivar, Calhoun, Carroll and 32 more	2 hr
Apr 14, 6:57 AM CDT	Tornado Watch	SPC	Amite, Attala, Choctaw, Clarke, Clay, Copiah and 30 more	7 hr

Nearby

Mesoscale Discussions in Alabama, 2018 Mesoscale Discussions in Florida, 2018 Mesoscale Discussions in Mississippi, 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.