Alert archive / Mississippi / Mesoscale Discussions in 2016

Mesoscale Discussion 1854

November 30, 201620 parishes in Louisiana; 23 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Nov 30, 2016, 3:33 AM CST for 20 parishes in Louisiana; 23 counties in Mississippi. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
Nov 30, 2016, 3:33 AM CST (09:33 UTC)
Expired
Nov 30, 2016, 5:00 AM CST
In force
87 min
Issued by
the Storm Prediction Center
All 43 counties

Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Orleans 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, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, Amite County, MS, Clarke County, MS, Covington County, MS, Forrest County, MS, Hancock County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Newton County, MS, Noxubee County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Wayne 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, 9.6 hours before the alert went out and 189 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 2016-11-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1191 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 2016-11-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 391 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
1191 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
883 m above ground
0-6 km bulk shear
77 kt
0-1 km storm-relative helicity
391 m²/s²
0-3 km storm-relative helicity
488 m²/s²
Significant tornado parameter
3.5
Supercell composite
15.4

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
Nov 29, 6:06 PM CSTMesoscale DiscussionSPCCaldwell, Catahoula, Concordia, East Carroll, Franklin, Grant and 6 more114 min
Nov 29, 8:03 PM CSTMesoscale DiscussionSPCAcadia, Allen, Ascension, Avoyelles, Catahoula, Concordia and 23 more2 hr
Nov 29, 8:50 PM CSTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Catahoula and 27 more8 hr
Nov 29, 9:47 PM CSTMesoscale DiscussionSPCConcordia58 min
Nov 29, 11:37 PM CSTMesoscale DiscussionSPCAcadia, Ascension, Avoyelles, Catahoula, Concordia, East Baton Rouge and 18 more113 min
Nov 30, 4:57 AM CSTTornado WatchSPCAscension, Assumption, East Baton Rouge, Iberia, Iberville, Jefferson and 17 more7 hr
Nov 29, 6:43 PM CSTMesoscale DiscussionSPCAlcorn, Chickasaw, Clay, Itawamba, Lee, Lowndes and 6 more92 min
Nov 30, 9:00 AM CSTMesoscale DiscussionSPCGeorge, Greene, Harrison, Jackson2 hr

Nearby

Mesoscale Discussions in Mississippi, 2016Mesoscale Discussions in Louisiana, 2016Every mesoscale discussion in 2016

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.