Alert archive / Louisiana / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 674
The Storm Prediction Center issued this severe thunderstorm watch at Nov 5, 2012, 5:29 PM CST for 32 parishes in Louisiana; 4 counties in Mississippi. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 5, 2012, 5:29 PM CST (23:29 UTC)
- Expired
- Nov 5, 2012, 11:26 PM CST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 36 counties
Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Jefferson Parish, LA, Lafayette 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 Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS
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
- 20%
- One or more gusts of 65 knots or more
- 5%
- 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
- 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 |
|---|---|---|---|---|
| Nov 5, 6:22 PM CST | Severe Thunderstorm Warning | LCH | Iberia, Lafayette, Saint Martin, St. Mary | 53 min |
| Nov 5, 6:32 PM CST | Severe Thunderstorm Warning | LIX | Livingston | 43 min |
| Nov 5, 6:49 PM CST | Severe Thunderstorm Warning | LIX | Ascension, East Baton Rouge, Livingston | 41 min |
| Nov 5, 7:06 PM CST | Severe Thunderstorm Warning | LIX | Ascension, Assumption, Iberville, Lafourche, Saint James | 54 min |
| Nov 5, 7:10 PM CST | Severe Thunderstorm Warning | LCH | Iberia, Saint Martin | 17 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, 11.5 hours before the alert went out and 122 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1067 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- -24 m²/s²
- 0-3 km storm-relative helicity
- 12 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 5, 1:19 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 21 more | 86 min |
| Nov 5, 2:08 PM CST | Severe Thunderstorm Watch | SPC | Beauregard, Calcasieu, Cameron | 7 hr |
| Nov 5, 4:43 PM CST | Mesoscale Discussion | SPC | Acadia, Ascension, Assumption, East Baton Rouge, East Feliciana, Evangeline and 22 more | 92 min |
| Nov 5, 5:25 PM CST | Mesoscale Discussion | SPC | Allen, Beauregard, Calcasieu, Cameron, Jefferson Davis | 95 min |
Nearby
Severe Thunderstorm Watches in Louisiana, 2012Severe Thunderstorm Watches in Mississippi, 2012Every severe thunderstorm watch in 2012
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.