Alert archive / Louisiana / Tornado Watches in 2016
Tornado Watch 512
The Storm Prediction Center issued this tornado watch at Nov 30, 2016, 4:57 AM CST for 4 counties in Alabama; 23 parishes in Louisiana; 18 counties in Mississippi. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 30, 2016, 4:57 AM CST (10:57 UTC)
- Expired
- Nov 30, 2016, 12:00 PM CST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 45 counties
Choctaw County, AL, Clarke County, AL, Mobile County, AL, Washington County, AL, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines 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 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, Clarke County, MS, Covington County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jasper County, MS, Jones County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Stone County, MS, Walthall 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
- 30%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 20%
- 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
- 50%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 30, 10:11 AM CST | Tornado Warning | LIX | Harrison | 19 min |
| Nov 30, 11:32 AM CST | Severe Thunderstorm Warning | MOB | Mobile | 43 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, 11.0 hours before the alert went out and 42 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
- 1629 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 576 m above ground
- 0-6 km bulk shear
- 64 kt
- 0-1 km storm-relative helicity
- 237 m²/s²
- 0-3 km storm-relative helicity
- 249 m²/s²
- Significant tornado parameter
- 2.8
- Supercell composite
- 9.8
The text
As transmitted.
992 WWUS20 KWNS 301054 SEL2 SPC WW 301054 ALZ000-LAZ000-MSZ000-CWZ000-301800- URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 512 NWS STORM PREDICTION CENTER NORMAN OK 455 AM CST WED NOV 30 2016 THE NWS STORM PREDICTION CENTER HAS ISSUED A * TORNADO WATCH FOR PORTIONS OF SOUTHWESTERN ALABAMA SOUTHEASTERN LOUISIANA SOUTHEASTERN MISSISSIPPI COASTAL WATERS * EFFECTIVE THIS WEDNESDAY MORNING FROM 455 AM UNTIL NOON CST. * PRIMARY THREATS INCLUDE... A COUPLE TORNADOES POSSIBLE ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE SUMMARY...TWO BANDS OF CONVECTION -- ONE CURRENTLY EXTENDING FROM NORTHERN ALABAMA TO OFFSHORE THE LOUISIANA COAST...THE OTHER A SMALLER LINE OVER SOUTHEASTERN MISSISSIPPI AND SOUTHWESTERN ALABAMA -- WILL POSE A RISK OF DAMAGING GUSTS AND MOSTLY SMALL/BRIEF TORNADOES THROUGH THE REMAINDER OF THE MORNING HOURS WHILE CROSSING THE WATCH AREA. THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE MILES EITHER SIDE OF A LINE FROM 50 MILES SOUTHWEST OF HOUMA LA TO 55 MILES SOUTHEAST OF MERIDIAN MS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. && OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO WATCH NUMBER 508. WATCH NUMBER 508 WILL NOT BE IN EFFECT AFTER 455 AM CST. CONTINUE...WW 511... AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 1 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 24035. ...EDWARDS
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 29, 6:43 PM CST | Mesoscale Discussion | SPC | Colbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 6 more | 92 min |
| Nov 29, 6:47 PM CST | Tornado Watch | SPC | Cullman, DeKalb, Jackson, Lawrence, Limestone, Madison and 2 more | 8 hr |
| Nov 29, 8:03 PM CST | Mesoscale Discussion | SPC | Choctaw, Fayette, Greene, Hale, Lamar, Pickens and 2 more | 2 hr |
| Nov 29, 8:50 PM CST | Tornado Watch | SPC | Bibb, Blount, Fayette, Greene, Hale, Jefferson and 7 more | 8 hr |
| Nov 29, 9:28 PM CST | Mesoscale Discussion | SPC | Cullman, DeKalb, Jackson, Lawrence, Limestone, Madison and 2 more | 62 min |
| Nov 29, 10:28 PM CST | Tornado Watch | SPC | Colbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more | 5 hr |
| Nov 29, 11:17 PM CST | Mesoscale Discussion | SPC | DeKalb, Jackson, Lawrence, Limestone, Madison, Morgan | 118 min |
| Nov 29, 11:37 PM CST | Mesoscale Discussion | SPC | Fayette, Lamar, Pickens | 113 min |
| Nov 30, 1:07 AM CST | Mesoscale Discussion | SPC | Blount, Cullman, DeKalb, Fayette, Jackson, Madison and 5 more | 53 min |
| Nov 30, 2:54 AM CST | Tornado Watch | SPC | Bibb, Blount, Calhoun, Cherokee, Chilton, Cleburne and 22 more | 7 hr |
| Nov 30, 5:10 AM CST | Mesoscale Discussion | SPC | Bibb, Blount, Calhoun, Cherokee, Chilton, Clay and 27 more | 95 min |
| Nov 30, 9:00 AM CST | Mesoscale Discussion | SPC | Autauga, Baldwin, Bibb, Blount, Bullock, Butler and 37 more | 2 hr |
| Nov 30, 11:06 AM CST | Tornado Watch | SPC | Baldwin, Barbour, Bullock, Butler, Chambers, Coffee and 17 more | 6 hr |
| Nov 30, 12:59 PM CST | Mesoscale Discussion | SPC | Barbour, Bullock, Coffee, Covington, Crenshaw, Dale and 7 more | 2 hr |
| Nov 30, 1:55 PM CST | Mesoscale Discussion | SPC | Barbour, Coffee, Covington, Dale, Geneva, Henry and 2 more | 2 hr |
| Nov 29, 6:06 PM CST | Mesoscale Discussion | SPC | Caldwell, Catahoula, Concordia, East Carroll, Franklin, Grant and 6 more | 114 min |
| Nov 29, 9:47 PM CST | Mesoscale Discussion | SPC | Concordia | 58 min |
| Nov 30, 3:33 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 14 more | 87 min |
Nearby
Tornado Watches in Louisiana, 2016Tornado Watches in Mississippi, 2016Tornado Watches in Alabama, 2016Every tornado watch in 2016
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.