Alert archive / Louisiana / Tornado Watches in 2016

Tornado Watch 19

February 23, 201629 parishes in Louisiana; 8 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Feb 23, 2016, 11:08 AM CST for 29 parishes in Louisiana; 8 counties in Mississippi. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Feb 23, 2016, 11:08 AM CST (17:08 UTC)
Expired
Feb 23, 2016, 6:00 PM CST
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 37 counties

Acadia Parish, LA, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville 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, Amite County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Pike County, MS, Walthall County, MS, Wilkinson 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
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

36 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Feb 23, 11:11 AM CSTTornado WarningLIXSaint Charles, Saint John the Baptist19 min
Feb 23, 11:13 AM CSTTornado WarningLIXJefferson17 min
Feb 23, 11:45 AM CSTTornado WarningLIXAscension, East Baton Rouge, Iberville30 min
Feb 23, 11:58 AM CSTTornado WarningLIXSaint Tammany32 min
Feb 23, 12:11 PM CSTTornado WarningLIXAscension, East Baton Rouge, Livingston34 min
Feb 23, 12:26 PM CSTTornado WarningLIXSaint Tammany34 min
Feb 23, 12:40 PM CSTTornado Warning Tornado observedLIXLivingston, Saint Helena, Tangipahoa35 min
Feb 23, 12:54 PM CSTSevere Thunderstorm WarningLCHAcadia, Lafayette, Saint Landry, Saint Martin, Vermilion30 min
Feb 23, 12:59 PM CSTTornado WarningLIXSaint Tammany31 min
Feb 23, 1:03 PM CSTTornado WarningLIXAscension, Livingston, Saint James, Saint John the Baptist27 min
Feb 23, 1:11 PM CSTTornado WarningLIXSaint Helena, Tangipahoa34 min
Feb 23, 1:14 PM CSTSevere Thunderstorm WarningLIXAscension, Assumption, Iberville, Saint James46 min
Feb 23, 1:30 PM CSTSevere Thunderstorm WarningLIXAscension, Assumption, Iberville, Livingston, Saint James, Saint John the Baptist30 min
Feb 23, 1:30 PM CSTSevere Thunderstorm WarningLIXPearl River45 min
Feb 23, 1:51 PM CSTTornado WarningLIXWashington24 min
Feb 23, 2:28 PM CSTFlash Flood WarningLCHSt. Mary3 hr
Feb 23, 2:35 PM CSTSevere Thunderstorm WarningLIXAscension, Livingston, Saint James, Saint John the Baptist, Tangipahoa25 min
Feb 23, 3:03 PM CSTSevere Thunderstorm WarningLIXAscension, Assumption, Iberville, Lafourche, Saint James27 min
Feb 23, 3:11 PM CSTTornado WarningLIXAscension, East Baton Rouge, Iberville18 min
Feb 23, 3:19 PM CSTTornado WarningLIXAscension, Assumption, Iberville, Saint James26 min
Feb 23, 3:27 PM CSTTornado WarningLIXPlaquemines48 min
Feb 23, 3:38 PM CSTTornado Warning Tornado observedConsiderable damage threatLIXAscension, Livingston, Saint James, Saint John the Baptist37 min
Feb 23, 3:42 PM CSTSevere Thunderstorm WarningLIXSaint Tammany, Washington33 min
Feb 23, 3:52 PM CSTTornado WarningLIXPearl River8 min
Feb 23, 3:54 PM CSTSevere Thunderstorm WarningLIXHarrison, Jackson36 min
Feb 23, 3:56 PM CSTTornado WarningLIXPearl River17 min
Feb 23, 4:01 PM CSTTornado WarningLIXSaint John the Baptist, Saint Tammany, Tangipahoa29 min
Feb 23, 4:15 PM CSTSevere Thunderstorm WarningLIXPearl River30 min
Feb 23, 4:27 PM CSTTornado WarningLIXSaint Tammany, Tangipahoa33 min
Feb 23, 4:34 PM CSTTornado WarningLIXSaint John the Baptist26 min
Feb 23, 4:48 PM CSTTornado WarningLIXSaint Tammany27 min
Feb 23, 5:09 PM CSTTornado WarningLIXSaint Tammany36 min
Feb 23, 5:13 PM CSTSevere Thunderstorm WarningLIXSaint Tammany, Washington47 min
Feb 23, 5:22 PM CSTSevere Thunderstorm WarningLCHAllen, Avoyelles, Evangeline, Saint Landry40 min
Feb 23, 5:42 PM CSTTornado WarningLIXSaint Tammany33 min
Feb 23, 5:50 PM CSTTornado WarningLIXJackson25 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, 5.1 hours before the alert went out and 128 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.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 12:00Z on 2016-02-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 42 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Slidell Radar S, LA at 12:00Z on 2016-02-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 118 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
42 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
667 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
118 m²/s²
0-3 km storm-relative helicity
129 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

875 
WWUS20 KWNS 231706
SEL9  
SPC WW 231706
LAZ000-MSZ000-CWZ000-232300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 19
NWS STORM PREDICTION CENTER NORMAN OK
1110 AM CST TUE FEB 23 2016

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  SOUTH CENTRAL AND SOUTHEAST LOUISIANA
  EXTREME SOUTHERN MISSISSIPPI
  COASTAL WATERS

* EFFECTIVE THIS TUESDAY MORNING AND AFTERNOON FROM 1110 AM UNTIL
  500 PM CST.

* PRIMARY THREATS INCLUDE...
  A FEW TORNADOES POSSIBLE
  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
  ISOLATED LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE

SUMMARY...SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP AND
SPREAD NORTHEASTWARD ACROSS SOUTH CENTRAL AND SOUTHEAST LOUISIANA
THROUGH THE AFTERNOON...AS THE STORM ENVIRONMENT GRADUALLY BECOMES
MORE FAVORABLE FOR TORNADOES.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE
MILES EAST AND WEST OF A LINE FROM 60 MILES NORTHEAST OF BATON
ROUGE LOUISIANA TO 45 MILES SOUTHWEST OF HOUMA LOUISIANA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU9).

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.

&&

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 24035.


...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 23, 10:44 AM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, Iberia, Iberville, Jefferson and 13 more91 min
Feb 23, 12:25 PM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 19 more65 min
Feb 23, 1:15 PM CSTMesoscale DiscussionSPCEast Feliciana, Saint Helena, Saint Tammany, Tangipahoa, Washington2 hr
Feb 23, 2:13 PM CSTTornado Watch PDSSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 4 more8 hr
Feb 23, 3:08 PM CSTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 4 more97 min
Feb 23, 5:18 PM CSTMesoscale DiscussionSPCSaint Tammany117 min
Feb 23, 2:20 PM CSTTornado WatchSPCAdams, Attala, Carroll, Choctaw, Claiborne, Clay and 26 more6 hr
Feb 23, 3:30 PM CSTMesoscale DiscussionSPCClaiborne, Copiah, Hinds, Madison, Rankin, Yazoo90 min

Nearby

Tornado Watches in Louisiana, 2016Tornado Watches in Mississippi, 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.