Alert archive / Louisiana / Severe Thunderstorm Watches in 2013
Severe Thunderstorm Watch 75
The Storm Prediction Center issued this severe thunderstorm watch at Mar 31, 2013, 3:38 PM CDT for 11 parishes in Louisiana; 9 counties in Mississippi. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 31, 2013, 3:38 PM CDT (20:38 UTC)
- Expired
- Mar 31, 2013, 6:57 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
Counties Assumption Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Terrebonne Parish, LA, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Wayne County, MS
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 10%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 31, 3:56 PM CDT | Severe Thunderstorm Warning | LIX | Ascension, Livingston, Saint Charles, Saint James, Saint John the Baptist, Saint Tammany and 1 more | 49 min |
| Mar 31, 4:24 PM CDT | Severe Thunderstorm Warning | LIX | Pearl River | 51 min |
| Mar 31, 4:37 PM CDT | Severe Thunderstorm Warning | LIX | Pearl River | 23 min |
| Mar 31, 4:41 PM CDT | Severe Thunderstorm Warning | LIX | Saint Tammany | 49 min |
| Mar 31, 5:55 PM CDT | Severe Thunderstorm Warning | MOB | George, Greene, Perry, Stone | 50 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
Slidell Radar S, LA (KSIL), launched 12:00Z, 8.6 hours before the alert went out and 48 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
- 321 J/kg
- Mixed-layer CIN
- -49 J/kg
- Mixed-layer LCL
- 513 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 74 m²/s²
- 0-3 km storm-relative helicity
- 56 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 31, 7:36 AM CDT | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 3 more | 114 min |
| Mar 31, 9:20 AM CDT | Severe Thunderstorm Watch | SPC | Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more | 5 hr |
| Mar 31, 10:33 AM CDT | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 5 more | 57 min |
| Mar 31, 11:54 AM CDT | Mesoscale Discussion | SPC | Allen, Avoyelles, Beauregard, Caldwell, Catahoula, Concordia and 20 more | 36 min |
| Mar 31, 12:17 PM CDT | Severe Thunderstorm Watch | SPC | Acadia, Allen, Ascension, Avoyelles, Beauregard, Calcasieu and 32 more | 6 hr |
| Mar 31, 2:32 PM CDT | Mesoscale Discussion | SPC | Allen, Avoyelles, Beauregard, Calcasieu, Caldwell, Catahoula and 21 more | 58 min |
| Mar 31, 2:48 PM CDT | Severe Thunderstorm Watch | SPC | Cameron, Iberia, Saint Martin, St. Mary, Vermilion | 5 hr |
| Mar 31, 3:21 PM CDT | Mesoscale Discussion | SPC | Jefferson, Orleans, Saint Charles, Saint James, Saint John the Baptist, Saint Tammany and 1 more | 54 min |
Nearby
Severe Thunderstorm Watches in Louisiana, 2013Severe Thunderstorm Watches in Mississippi, 2013Every severe thunderstorm watch in 2013
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.