Alert archive / Louisiana / Severe Thunderstorm Watches in 2009
Severe Thunderstorm Watch 2
The Storm Prediction Center issued this severe thunderstorm watch at Jan 3, 2009, 4:29 PM CST for Ashley County, Chicot County, Arkansas; 15 parishes in Louisiana; 8 counties in Mississippi. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 3, 2009, 4:29 PM CST (22:29 UTC)
- Expired
- Jan 3, 2009, 7:17 PM CST
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 25 counties
Ashley County, AR, Chicot County, AR, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Richland Parish, LA, Tensas Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Claiborne County, MS, Franklin County, MS, Issaquena County, MS, Jefferson County, MS, Sharkey County, MS, Warren County, MS, Washington County, MS
The radar
The Jackson/Brandon,MS radar (KDGX), 150 km from the middle of the area, began a volume at 22:29 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 3, 5:00 PM CST | Severe Thunderstorm Warning | SHV | LaSalle | 55 min |
| Jan 3, 5:34 PM CST | Severe Thunderstorm Warning | JAN | Catahoula, Franklin | 26 min |
| Jan 3, 5:59 PM CST | Severe Thunderstorm Warning | JAN | Catahoula, Franklin | 26 min |
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, 10.5 hours before the alert went out and 140 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
- 863 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 474 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 160 m²/s²
- 0-3 km storm-relative helicity
- 162 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 3, 7:32 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Ascension, Assumption, Cameron, East Baton Rouge and 26 more | 88 min |
| Jan 3, 9:33 AM CST | Severe Thunderstorm Watch | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 21 more | 6 hr |
| Jan 3, 12:32 PM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Catahoula, Concordia, East Baton Rouge, East Feliciana and 21 more | 88 min |
| Jan 3, 4:27 PM CST | Mesoscale Discussion | SPC | Avoyelles, Caldwell, Catahoula, Concordia, Franklin, Grant and 9 more | 33 min |
Nearby
Severe Thunderstorm Watches in Louisiana, 2009Severe Thunderstorm Watches in Mississippi, 2009Severe Thunderstorm Watches in Arkansas, 2009Every severe thunderstorm watch in 2009
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.