Alert archive / Louisiana / Mesoscale Discussions in 2018
Mesoscale Discussion 80
The Storm Prediction Center issued this mesoscale discussion at Feb 21, 2018, 9:07 AM CST for 18 parishes in Louisiana; Newton County, Orange County, Texas. It was in force for 113 min.
The area
The outline as issued.
The facts
- Issued
- Feb 21, 2018, 9:07 AM CST (15:07 UTC)
- Expired
- Feb 21, 2018, 11:00 AM CST
- In force
- 113 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
Counties Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Jefferson Davis Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Saint Landry Parish, LA, Vernon Parish, LA, Winn Parish, LA, Newton County, TX, Orange County, TX
The radar
The Ft Polk radar (KPOE), 50 km from the middle of the area, began a volume at 15:06 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
Lake Charles Mun, LA (KLCH), launched 12:00Z, 3.1 hours before the alert went out and 99 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
- 1458 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 474 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 203 m²/s²
- 0-3 km storm-relative helicity
- 188 m²/s²
- Significant tornado parameter
- 1.3
- Supercell composite
- 10.0
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 |
|---|---|---|---|---|
| Feb 21, 9:48 AM CST | Tornado Watch | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 17 more | 7 hr |
| Feb 21, 12:28 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 17 more | 92 min |
| Feb 21, 3:03 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 20 more | 117 min |
| Feb 21, 7:57 AM CST | Mesoscale Discussion | SPC | Archer, Baylor, Borden, Callahan, Childress, Clay and 35 more | 4 hr |
| Feb 21, 12:44 PM CST | Mesoscale Discussion | SPC | Clay, Cooke, Denton, Jack, Montague, Palo Pinto and 1 more | 4 hr |
Nearby
Mesoscale Discussions in Louisiana, 2018Mesoscale Discussions in Texas, 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.