Alert archive / Mississippi / Mesoscale Discussions in 2018

Mesoscale Discussion 1607

October 31, 201815 parishes in Louisiana; 38 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Oct 31, 2018, 10:01 PM CDT for 15 parishes in Louisiana; 38 counties in Mississippi. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Oct 31, 2018, 10:01 PM CDT (03:01 UTC)
Expired
Oct 31, 2018, 11:30 PM CDT
In force
89 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 53 counties

Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Martin Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Attala County, MS, Calhoun County, MS, Carroll County, MS, Claiborne County, MS, Coahoma County, MS, Copiah County, MS, Franklin County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Jefferson Davis County, MS, Lafayette County, MS, Lawrence County, MS, Leake County, MS, Leflore County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Montgomery County, MS, Panola County, MS, Pike County, MS, Quitman County, MS, Rankin County, MS, Sharkey County, MS, Simpson County, MS, Sunflower County, MS, Tallahatchie County, MS, Walthall County, MS, Warren County, MS, Washington County, MS, Wilkinson County, MS, Yalobusha County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 86 km from the middle of the area, began a volume at 03:04 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 00:00Z, 3.0 hours before the alert went out and 83 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 2018-11-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 97 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 2018-11-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 118 square meters per square second.19395878Sfc1 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
97 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
1135 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
118 m²/s²
0-3 km storm-relative helicity
215 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

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
Oct 31, 7:28 PM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 20 more92 min
Oct 31, 8:14 PM CDTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 30 more8 hr
Oct 31, 11:07 PM CDTTornado WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 17 more9 hr
Oct 31, 11:52 PM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 25 more53 min
Nov 1, 1:19 AM CDTMesoscale DiscussionSPCAcadia, Ascension, Assumption, Avoyelles, Catahoula, Concordia and 30 more116 min
Nov 1, 4:30 AM CDTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 5 more2 hr
Oct 31, 7:04 PM CDTMesoscale DiscussionSPCBenton, Marshall116 min
Nov 1, 1:41 AM CDTMesoscale DiscussionSPCAlcorn, Benton, DeSoto, Marshall, Prentiss, Tate and 3 more3 hr

Nearby

Mesoscale Discussions in Mississippi, 2018Mesoscale Discussions in Louisiana, 2018Every mesoscale discussion in 2018

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.