Alert archive / Mississippi / Mesoscale Discussions in 2020

Mesoscale Discussion 1644

August 30, 202033 counties in Alabama; 36 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Aug 30, 2020, 1:39 PM CDT for 33 counties in Alabama; 36 counties in Mississippi. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Aug 30, 2020, 1:39 PM CDT (18:39 UTC)
Expired
Aug 30, 2020, 4:15 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%
All 69 counties

Bibb County, AL, Blount County, AL, Calhoun County, AL, Cherokee County, AL, Chilton County, AL, Clay County, AL, Cleburne County, AL, Colbert County, AL, Coosa County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Alcorn County, MS, Attala County, MS, Benton County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Itawamba County, MS, Kemper County, MS, Lafayette County, MS, Leake County, MS, Lee County, MS, Leflore County, MS, Lowndes County, MS, Madison County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Noxubee County, MS, Oktibbeha County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Sharkey County, MS, Tallahatchie County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS, Yazoo County, MS

The radar

The Columbus AFB radar (KGWX), 45 km from the middle of the area, began a volume at 18:38 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

Little Rock, AR (KLZK), launched 12:00Z, 6.7 hours before the alert went out and 180 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-pSkew-T log-p diagram, Little Rock, AR at 12:00Z on 2020-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Little Rock, AR at 12:00Z on 2020-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
3 J/kg
Mixed-layer CIN
-385 J/kg
Mixed-layer LCL
1139 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
-18 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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Nearby

Mesoscale Discussions in Mississippi, 2020Mesoscale Discussions in Alabama, 2020Every 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.