Alert archive / Mississippi / Mesoscale Discussions in 2020

Mesoscale Discussion 357

April 12, 20207 counties in Alabama; 20 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2020, 3:38 PM CDT for 7 counties in Alabama; 20 counties in Mississippi. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Apr 12, 2020, 3:38 PM CDT (20:38 UTC)
Expired
Apr 12, 2020, 5:15 PM CDT
In force
97 min
Issued by
the Storm Prediction Center
All 27 counties

Fayette County, AL, Greene County, AL, Lamar County, AL, Pickens County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Copiah County, MS, Covington County, MS, Jasper County, MS, Jefferson Davis County, MS, Kemper County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Lowndes County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 103 km from the middle of the area, began a volume at 20:40 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.

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 8.6 hours before the alert went out and 110 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, Jackson, MS at 12:00Z on 2020-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 323 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, Jackson, MS at 12:00Z on 2020-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 379 square meters per square second.1939587897117Sfc1 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
323 J/kg
Mixed-layer CIN
-279 J/kg
Mixed-layer LCL
625 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
379 m²/s²
0-3 km storm-relative helicity
562 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

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.

IssuedProductOfficeCountiesLasted
Apr 12, 1:45 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Calhoun, Cherokee, Chilton and 33 more90 min
Apr 12, 3:20 PM CDTTornado WatchSPCBibb, Blount, Calhoun, Cherokee, Chilton, Clay and 30 more8 hr
Apr 12, 3:53 PM CDTMesoscale DiscussionSPCClarke, Washington97 min
Apr 12, 4:38 PM CDTTornado Watch PDSSPCAutauga, Baldwin, Bibb, Calhoun, Chilton, Choctaw and 22 more7 hr
Apr 12, 4:54 PM CDTMesoscale DiscussionSPCChoctaw66 min
Apr 12, 5:14 PM CDTMesoscale DiscussionSPCBlount, Calhoun, Cherokee, Cleburne, Cullman, DeKalb and 13 more91 min
Apr 12, 5:44 PM CDTMesoscale DiscussionSPCLamar, Marion91 min
Apr 12, 7:18 AM CDTMesoscale DiscussionSPCWarren87 min
Apr 12, 10:24 AM CDTMesoscale DiscussionSPCAdams, Attala, Calhoun, Carroll, Chickasaw, Choctaw and 42 more96 min
Apr 12, 10:41 AM CDTTornado Watch PDSSPCAdams, Attala, Bolivar, Calhoun, Carroll, Chickasaw and 47 more10 hr
Apr 12, 12:03 PM CDTMesoscale DiscussionSPCAttala, Carroll, Hinds, Holmes, Humphreys, Issaquena and 6 more87 min
Apr 12, 1:02 PM CDTMesoscale DiscussionSPCAmite, Hancock, Lamar, Marion, Pearl River, Pike and 1 more118 min
Apr 12, 1:24 PM CDTTornado WatchSPCAmite, Covington, Forrest, Franklin, Hancock, Harrison and 11 more9 hr
Apr 12, 1:40 PM CDTMesoscale DiscussionSPCAttala, Choctaw, Hinds, Holmes, Kemper, Lauderdale and 10 more95 min
Apr 12, 3:52 PM CDTMesoscale DiscussionSPCCovington, Jefferson Davis, Jones, Marion23 min
Apr 12, 4:26 PM CDTMesoscale DiscussionSPCCovington, Jasper, Jones34 min
Apr 12, 5:27 PM CDTMesoscale DiscussionSPCAmite, Pike, Walthall63 min

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.