Alert archive / Louisiana / Tornado Watches in 2010
Tornado Watch 769
The Storm Prediction Center issued this tornado watch at Dec 31, 2010, 11:39 AM CST for 10 counties in Alabama; 22 parishes in Louisiana; 20 counties in Mississippi. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 31, 2010, 11:39 AM CST (17:39 UTC)
- Expired
- Dec 31, 2010, 7:00 PM CST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 52 counties
Baldwin County, AL, Butler County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Escambia County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Wilcox County, AL, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Covington County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS, Wilkinson County, MS
The radar
The Mobile radar (KMOB), 117 km from the middle of the area, began a volume at 17:40 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 60%
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Jackson, MS (KJAN), launched 12:00Z, 5.7 hours before the alert went out and 149 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
- 100 J/kg
- Mixed-layer CIN
- -119 J/kg
- Mixed-layer LCL
- 580 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 343 m²/s²
- 0-3 km storm-relative helicity
- 523 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 31, 9:42 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Livingston, Orleans and 8 more | 2 hr |
| Dec 31, 10:36 AM CST | Mesoscale Discussion | SPC | Bossier, Caddo | 114 min |
| Dec 31, 12:44 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 10 more | 2 hr |
| Dec 31, 1:34 PM CST | Tornado Watch | SPC | Allen, Avoyelles, Beauregard, Caldwell, Catahoula, Concordia and 17 more | 6 hr |
| Dec 31, 2:58 PM CST | Mesoscale Discussion | SPC | East Baton Rouge, East Feliciana, Saint Helena, Tangipahoa, Washington, West Baton Rouge and 1 more | 92 min |
| Dec 31, 3:58 PM CST | Tornado Watch | SPC | Catahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more | 7 hr |
| Dec 31, 5:35 PM CST | Mesoscale Discussion | SPC | Alcorn, Benton, Bolivar, Calhoun, Coahoma, DeSoto and 16 more | 115 min |
Nearby
Tornado Watches in Louisiana, 2010Tornado Watches in Mississippi, 2010Tornado Watches in Alabama, 2010Every tornado watch in 2010
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.