Alert archive / Louisiana / Mesoscale Discussions in 2013

Mesoscale Discussion 91

January 30, 2013Mobile County, Washington County, Alabama; 23 parishes in Louisiana; 14 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jan 30, 2013, 4:27 AM CST for Mobile County, Washington County, Alabama; 23 parishes in Louisiana; 14 counties in Mississippi. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Jan 30, 2013, 4:27 AM CST (10:27 UTC)
Expired
Jan 30, 2013, 6:00 AM CST
In force
93 min
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 39 counties

Mobile County, AL, Washington County, AL, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, Amite County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Stone County, MS, Walthall County, MS

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 00:00Z, 10.5 hours before the alert went out and 259 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 00:00Z on 2013-01-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 63 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 00:00Z on 2013-01-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 213 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
63 J/kg
Mixed-layer CIN
-71 J/kg
Mixed-layer LCL
1274 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
213 m²/s²
0-3 km storm-relative helicity
375 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Jan 29, 9:49 PM CSTMesoscale DiscussionSPCColbert, Franklin, Lauderdale116 min
Jan 30, 1:31 AM CSTMesoscale DiscussionSPCBlount, Calhoun, Cherokee, Colbert, Cullman, DeKalb and 17 more29 min
Jan 30, 1:46 AM CSTTornado WatchSPCBlount, Colbert, Cullman, DeKalb, Fayette, Franklin and 16 more8 hr
Jan 30, 5:01 AM CSTMesoscale DiscussionSPCAutauga, Bibb, Bullock, Butler, Calhoun, Chambers and 26 more29 min
Jan 30, 5:15 AM CSTTornado WatchSPCAutauga, Baldwin, Barbour, Bibb, Bullock, Butler and 34 more7 hr
Jan 30, 7:43 AM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Blount, Bullock, Calhoun and 36 more62 min
Jan 30, 10:09 AM CSTMesoscale DiscussionSPCBarbour, Bullock, Chambers, Clay, Cleburne, Crenshaw and 9 more96 min
Jan 30, 11:50 AM CSTMesoscale DiscussionSPCBullock, Chambers, Elmore, Lee, Macon, Montgomery and 3 more85 min
Jan 30, 12:19 PM CSTTornado WatchSPCBarbour, Bullock, Butler, Chambers, Coffee, Conecuh and 16 more9 hr
Jan 29, 7:31 PM CSTMesoscale DiscussionSPCMadison, Tensas119 min
Jan 29, 8:11 PM CSTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 17 more94 min
Jan 30, 3:03 AM CSTMesoscale DiscussionSPCConcordia, Tensas57 min
Jan 29, 10:07 PM CSTTornado WatchSPCAdams, Alcorn, Attala, Benton, Calhoun, Carroll and 37 more6 hr
Jan 30, 3:45 AM CSTTornado WatchSPCAttala, Choctaw, Clarke, Clay, Copiah, Covington and 23 more4 hr

Nearby

Mesoscale Discussions in Louisiana, 2013Mesoscale Discussions in Mississippi, 2013Mesoscale Discussions in Alabama, 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.