Alert archive / Louisiana / Mesoscale Discussions in 2018
Mesoscale Discussion 1736
The Storm Prediction Center issued this mesoscale discussion at Dec 27, 2018, 9:00 AM CST for 12 parishes in Louisiana; 11 counties in Mississippi. It was in force for 60 min.
The area
The outline as issued.
The facts
- Issued
- Dec 27, 2018, 9:00 AM CST (15:00 UTC)
- Expired
- Dec 27, 2018, 10:00 AM CST
- In force
- 60 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 23 counties
Avoyelles Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Madison Parish, LA, Pointe Coupee Parish, LA, Saint Landry Parish, LA, Tensas Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Jefferson County, MS, Lincoln County, MS, Rankin County, MS, Warren County, MS, Wilkinson 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 12:00Z, 3.0 hours before the alert went out and 175 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 591 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 466 m²/s²
- 0-3 km storm-relative helicity
- 893 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 26, 11:40 PM CST | Mesoscale Discussion | SPC | Bossier, Caddo, De Soto | 2 hr |
| Dec 27, 12:02 AM CST | Severe Thunderstorm Watch | SPC | Bienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more | 5 hr |
| Dec 27, 1:39 AM CST | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 2 more | 2 hr |
| Dec 27, 3:09 AM CST | Mesoscale Discussion | SPC | Allen, Beauregard, Calcasieu, Cameron, Jefferson Davis, Vernon | 2 hr |
| Dec 27, 3:43 AM CST | Tornado Watch | SPC | Acadia, Allen, Beauregard, Calcasieu, Caldwell, Cameron and 10 more | 10 hr |
| Dec 27, 7:12 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 11 more | 2 hr |
| Dec 27, 9:29 AM CST | Tornado Watch | SPC | Ascension, Assumption, Avoyelles, Catahoula, Concordia, East Baton Rouge and 27 more | 9 hr |
| Dec 27, 1:50 PM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Catahoula, Concordia, East Baton Rouge, East Feliciana and 19 more | 85 min |
Nearby
Mesoscale Discussions in Louisiana, 2018Mesoscale Discussions in Mississippi, 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.