Alert archive / Louisiana / Mesoscale Discussions in 2018
Mesoscale Discussion 1732
The Storm Prediction Center issued this mesoscale discussion at Dec 27, 2018, 1:39 AM CST for 7 counties in Arkansas; 8 parishes in Louisiana. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 27, 2018, 1:39 AM CST (07:39 UTC)
- Expired
- Dec 27, 2018, 3:45 AM CST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
Counties Calhoun County, AR, Columbia County, AR, Hempstead County, AR, Lafayette County, AR, Nevada County, AR, Ouachita County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Lincoln Parish, LA, Red River Parish, LA, Webster Parish, LA
The radar
The Shreveport radar (KSHV), 73 km from the middle of the area, began a volume at 07:38 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 nearest sounding before it
Shreveport, LA (KBAD), launched 00:00Z, 7.7 hours before the alert went out and 65 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
- 836 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 280 m²/s²
- 0-3 km storm-relative helicity
- 510 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 27, 12:02 AM CST | Severe Thunderstorm Watch | SPC | Columbia, Hempstead, Howard, Lafayette, Little River, Miller and 2 more | 5 hr |
| Dec 26, 11:40 PM CST | Mesoscale Discussion | SPC | Bossier, Caddo, De Soto | 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, 9:00 AM CST | Mesoscale Discussion | SPC | Avoyelles, Catahoula, Concordia, East Baton Rouge, East Feliciana, Iberville and 6 more | 60 min |
| 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 Arkansas, 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.