Alert archive / Alabama / Mesoscale Discussions in 2020

Mesoscale Discussion 1202

July 12, 20204 states

The Storm Prediction Center issued this mesoscale discussion at Jul 12, 2020, 2:51 PM CDT for 4 states. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Jul 12, 2020, 2:51 PM CDT (19:51 UTC)
Expired: Jul 12, 2020, 4:15 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 40%

All 45 counties

Baldwin County, AL, Barbour County, AL, Bullock County, AL, Butler County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Pike County, AL, Russell County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Chattahoochee County, GA, Clay County, GA, Harris County, GA, Marion County, GA, Muscogee County, GA, Quitman County, GA, Randolph County, GA, Stewart County, GA, Talbot County, GA, Webster County, GA, Forrest County, MS, George County, MS, Greene County, MS, Jackson County, MS, Jones County, MS, Perry County, MS, Stone County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 149 km from the middle of the area, began a volume at 19:51 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.

Severe Thunderstorm Watch 364Jul 12, 3:40 PM CDT

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 7.9 hours before the alert went out and 174 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: 43 J/kg
Mixed-layer CIN: -299 J/kg
Mixed-layer LCL: 1793 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 37 m²/s²
0-3 km storm-relative helicity: 68 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
Jul 12, 10:46 AM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Blount, Chilton, Clay, Coosa and 17 more	119 min
Jul 12, 12:09 PM CDT	Severe Thunderstorm Watch	SPC	Autauga, Barbour, Bibb, Blount, Bullock, Calhoun and 29 more	6 hr
Jul 12, 1:40 PM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Chambers, Chilton, Clay, Coosa and 5 more	95 min
Jul 12, 3:40 PM CDT	Severe Thunderstorm Watch	SPC	Baldwin, Butler, Choctaw, Clarke, Coffee, Conecuh and 11 more	6 hr
Jul 12, 6:28 PM CDT	Mesoscale Discussion	SPC	Baldwin, Clarke, Coffee, Conecuh, Covington, Escambia and 3 more	92 min

Nearby

Mesoscale Discussions in Alabama, 2020 Mesoscale Discussions in Georgia, 2020 Mesoscale Discussions in Mississippi, 2020 Every mesoscale discussion in 2020

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.