Alert archive / Louisiana / Mesoscale Discussions in 2023
Mesoscale Discussion 74
The Storm Prediction Center issued this mesoscale discussion at Jan 18, 2023, 3:31 PM CST for 4 states. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- Jan 18, 2023, 3:31 PM CST (21:31 UTC)
- Expired
- Jan 18, 2023, 5:00 PM CST
- In force
- 89 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 24...25
All 29 counties
Ashley County, AR, Chicot County, AR, Desha County, AR, Allen Parish, LA, Beauregard Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Grant Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Richland Parish, LA, Tensas Parish, LA, Vernon Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Bolivar County, MS, Humphreys County, MS, Issaquena County, MS, Leflore County, MS, Sharkey County, MS, Sunflower County, MS, Washington County, MS, Newton County, TX
The radar
The Ft Polk radar (KPOE), 142 km from the middle of the area, began a volume at 21:31 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 (KSHV), launched 12:00Z, 9.5 hours before the alert went out and 160 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
- 471 J/kg
- Mixed-layer CIN
- -73 J/kg
- Mixed-layer LCL
- 605 m above ground
- 0-6 km bulk shear
- 62 kt
- 0-1 km storm-relative helicity
- 291 m²/s²
- 0-3 km storm-relative helicity
- 275 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 3.1
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 |
|---|---|---|---|---|
| Jan 18, 7:28 AM CST | Mesoscale Discussion | SPC | Clark, Columbia, Hempstead, Howard, Lafayette, Little River and 5 more | 2 hr |
| Jan 18, 9:02 AM CST | Tornado Watch | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 25 more | 9 hr |
| Jan 18, 11:48 AM CST | Mesoscale Discussion | SPC | Bradley, Calhoun, Cleveland, Columbia, Dallas, Grant and 3 more | 87 min |
| Jan 18, 12:30 PM CST | Mesoscale Discussion | SPC | Ashley, Chicot, Crittenden, Cross, Lee, Phillips and 1 more | 90 min |
| Jan 18, 2:34 PM CST | Tornado Watch | SPC | Ashley, Chicot, Crittenden, Lee, Phillips, St. Francis | 7 hr |
| Jan 18, 5:47 PM CST | Mesoscale Discussion | SPC | Catahoula, Concordia, East Carroll, Franklin, Madison, Tensas | 118 min |
Nearby
Mesoscale Discussions in Louisiana, 2023Mesoscale Discussions in Mississippi, 2023Mesoscale Discussions in Arkansas, 2023Every mesoscale discussion in 2023
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.