Alert archive / Alabama / Mesoscale Discussions in 2017

Mesoscale Discussion 447

April 5, 20179 counties in Alabama; Escambia County, Santa Rosa County, Florida; George County, Greene County, Jackson County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 5, 2017, 3:29 PM CDT for 9 counties in Alabama; Escambia County, Santa Rosa County, Florida; George County, Greene County, Jackson County, Mississippi. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Apr 5, 2017, 3:29 PM CDT (20:29 UTC)
Expired: Apr 5, 2017, 6:00 PM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Baldwin County, AL, Clarke County, AL, Conecuh County, AL, Escambia County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Santa Rosa County, FL, George County, MS, Greene County, MS, Jackson County, MS

The radar

The Mobile radar (KMOB), 73 km from the middle of the area, began a volume at 20:29 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, 8.5 hours before the alert went out and 214 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: 3549 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 564 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 105 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 3.1
Supercell composite: 10.6

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 4, 11:54 PM CDT	Mesoscale Discussion	SPC	Baldwin, Butler, Clarke, Coffee, Conecuh, Covington and 8 more	2 hr
Apr 5, 1:37 AM CDT	Severe Thunderstorm Watch	SPC	Autauga, Barbour, Bibb, Blount, Bullock, Butler and 42 more	6 hr
Apr 5, 3:41 AM CDT	Mesoscale Discussion	SPC	Autauga, Barbour, Bibb, Bullock, Butler, Chambers and 38 more	2 hr
Apr 5, 6:15 AM CDT	Mesoscale Discussion	SPC	Autauga, Barbour, Bibb, Bullock, Butler, Calhoun and 35 more	90 min
Apr 5, 6:54 AM CDT	Tornado Watch	SPC	Autauga, Baldwin, Barbour, Bibb, Bullock, Butler and 44 more	8 hr
Apr 5, 9:43 AM CDT	Mesoscale Discussion	SPC	Barbour, Chambers, Lee, Macon, Russell, Tallapoosa	2 hr
Apr 5, 11:54 AM CDT	Tornado Watch PDS	SPC	Dale, Geneva, Henry, Houston	10 hr
Apr 5, 1:02 PM CDT	Mesoscale Discussion	SPC	Blount, Cullman, DeKalb, Jackson, Jefferson, Lauderdale and 8 more	2 hr
Apr 5, 1:50 PM CDT	Tornado Watch	SPC	Autauga, Barbour, Bibb, Blount, Bullock, Calhoun and 36 more	8 hr
Apr 5, 2:12 PM CDT	Mesoscale Discussion	SPC	Barbour, Bullock, Dale, Henry, Houston, Lee and 2 more	93 min
Apr 5, 3:51 PM CDT	Mesoscale Discussion	SPC	Blount, Calhoun, Chambers, Cherokee, Chilton, Clay and 19 more	84 min
Apr 5, 6:57 PM CDT	Mesoscale Discussion	SPC	Autauga, Blount, Bullock, Calhoun, Chambers, Cherokee and 20 more	48 min
Apr 5, 10:38 AM CDT	Mesoscale Discussion	SPC	Leon	97 min

Nearby

Mesoscale Discussions in Alabama, 2017 Mesoscale Discussions in Mississippi, 2017 Mesoscale Discussions in Florida, 2017 Every mesoscale discussion in 2017

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.