Alert archive / Louisiana / Tornado Watches in 2018
Tornado Watch 426
The Storm Prediction Center issued this tornado watch at Nov 12, 2018, 4:34 AM CST for 4 states. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 12, 2018, 4:34 AM CST (10:34 UTC)
- Expired
- Nov 12, 2018, 12:00 PM CST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
All 27 counties
Baldwin County, AL, Mobile County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Assumption Parish, LA, Cameron Parish, LA, Iberia 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 Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, George County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Stone County, MS
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 50%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 10%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 20%
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 12, 5:09 AM CST | Tornado Warning | LIX | Lafourche | 11 min |
| Nov 12, 8:56 AM CST | Severe Thunderstorm Warning | MOB | Escambia, Santa Rosa | 29 min |
| Nov 12, 8:59 AM CST | Tornado Warning | MOB | Escambia, Santa Rosa | 19 min |
| Nov 12, 11:15 AM CST | Tornado Warning | MOB | Escambia, Santa Rosa | 45 min |
| Nov 12, 11:59 AM CST | Severe Thunderstorm Warning | MOB | Okaloosa, Santa Rosa | 13 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 00:00Z, 10.6 hours before the alert went out and 80 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
- 1807 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 66 m²/s²
- 0-3 km storm-relative helicity
- 174 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 12, 7:54 AM CST | Mesoscale Discussion | SPC | Baldwin, Mobile | 2 hr |
| Nov 12, 11:25 AM CST | Mesoscale Discussion | SPC | Baldwin, Covington, Escambia, Geneva, Mobile | 95 min |
| Nov 12, 11:46 AM CST | Tornado Watch | SPC | Baldwin, Coffee, Covington, Dale, Escambia, Geneva and 3 more | 7 hr |
| Nov 12, 3:51 PM CST | Mesoscale Discussion | SPC | Coffee, Covington, Dale, Geneva, Henry, Houston | 114 min |
| Nov 12, 4:01 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Iberia, Jefferson, Lafourche, Orleans and 9 more | 2 hr |
Nearby
Tornado Watches in Louisiana, 2018Tornado Watches in Mississippi, 2018Tornado Watches in Florida, 2018Every tornado watch 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.