Alert archive / Mississippi / Mesoscale Discussions in 2013

Mesoscale Discussion 277

March 18, 201327 counties in Alabama; 5 parishes in Louisiana; 29 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 18, 2013, 1:10 PM CDT for 27 counties in Alabama; 5 parishes in Louisiana; 29 counties in Mississippi. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Mar 18, 2013, 1:10 PM CDT (18:10 UTC)
Expired
Mar 18, 2013, 2:15 PM CDT
In force
65 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 61 counties

Bibb County, AL, Blount County, AL, Calhoun County, AL, Cherokee County, AL, Chilton County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Marengo County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, East Carroll Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Richland Parish, LA, West Carroll Parish, LA, Attala County, MS, Carroll County, MS, Choctaw County, MS, Clay County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Kemper County, MS, Lauderdale County, MS, Leake County, MS, Leflore County, MS, Lowndes County, MS, Madison County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS

The radar

The Columbus AFB radar (KGWX), 76 km from the middle of the area, began a volume at 18:11 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

Birmingham, AL (KBMX), launched 12:00Z, 6.2 hours before the alert went out and 169 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, Birmingham, AL at 12:00Z on 2013-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 196 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, Birmingham, AL at 12:00Z on 2013-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 298 square meters per square second.1939587897Sfc1 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
196 J/kg
Mixed-layer CIN
-139 J/kg
Mixed-layer LCL
520 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
298 m²/s²
0-3 km storm-relative helicity
281 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 18, 7:40 AM CDTMesoscale DiscussionSPCLauderdale, Limestone2 hr
Mar 18, 8:09 AM CDTSevere Thunderstorm WatchSPCColbert, Cullman, DeKalb, Fayette, Franklin, Jackson and 10 more7 hr
Mar 18, 12:44 PM CDTMesoscale DiscussionSPCBlount, Cherokee, Colbert, Cullman, DeKalb, Etowah and 15 more91 min
Mar 18, 1:11 PM CDTMesoscale DiscussionSPCAutauga, Barbour, Bullock, Butler, Chambers, Coffee and 19 more94 min
Mar 18, 1:31 PM CDTSevere Thunderstorm WatchSPCBibb, Blount, Calhoun, Cherokee, Cleburne, Colbert and 28 more8 hr
Mar 18, 3:16 PM CDTTornado WatchSPCAutauga, Barbour, Bullock, Chambers, Chilton, Clay and 10 more6 hr
Mar 18, 4:28 PM CDTMesoscale DiscussionSPCButler, Choctaw, Clarke, Conecuh, Covington, Monroe and 2 more32 min
Mar 18, 4:34 PM CDTSevere Thunderstorm WatchSPCButler, Choctaw, Clarke, Conecuh, Crenshaw, Monroe and 2 more5 hr
Mar 18, 4:57 PM CDTMesoscale DiscussionSPCBarbour, Bullock, Calhoun, Chambers, Clay, Cleburne and 11 more2 hr
Mar 17, 10:58 PM CDTMesoscale DiscussionSPCCoahoma, DeSoto, Tate, Tunica3 hr
Mar 18, 7:24 AM CDTMesoscale DiscussionSPCBolivar, Coahoma, Tunica3 hr

Nearby

Mesoscale Discussions in Mississippi, 2013Mesoscale Discussions in Alabama, 2013Mesoscale Discussions in Louisiana, 2013Every mesoscale discussion in 2013

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.