Alert archive / Louisiana / Tornado Watches in 2015

Tornado Watch 204

May 24, 201547 parishes in Louisiana; 30 counties in Mississippi

The Storm Prediction Center issued this tornado watch at May 24, 2015, 1:49 PM CDT for 47 parishes in Louisiana; 30 counties in Mississippi. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
May 24, 2015, 1:49 PM CDT (18:49 UTC)
Expired
May 24, 2015, 9:34 PM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 77 counties

Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, LaSalle Parish, LA, Livingston Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Richland 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, Tensas Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Bolivar County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hancock County, MS, Harrison County, MS, Hinds County, MS, Humphreys County, MS, Issaquena County, MS, Jackson County, MS, Jefferson County, MS, Jefferson Davis County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Pearl River County, MS, Pike County, MS, Rankin County, MS, Sharkey County, MS, Simpson County, MS, Sunflower County, MS, Walthall County, MS, Warren County, MS, Washington County, MS, Wilkinson County, MS, Yazoo County, MS

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
10%
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
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 24, 3:13 PM CDTSevere Thunderstorm WarningSHVCaldwell, Ouachita, Union29 min
May 24, 3:35 PM CDTSevere Thunderstorm WarningJANFranklin, Morehouse, Richland, West Carroll40 min
May 24, 4:13 PM CDTSevere Thunderstorm WarningJANEast Carroll, Morehouse, West Carroll47 min
May 24, 5:03 PM CDTSevere Thunderstorm WarningJANSharkey, Sunflower, Washington27 min
May 24, 5:06 PM CDTSevere Thunderstorm WarningJANCarroll, Holmes, Humphreys, Leflore, Yazoo54 min
May 24, 5:23 PM CDTSevere Thunderstorm WarningJANBolivar, Sunflower, Washington52 min
May 24, 5:28 PM CDTSevere Thunderstorm WarningLCHIberia, Saint Landry, Saint Martin, St. Mary62 min
May 24, 6:36 PM CDTSevere Thunderstorm WarningJANLincoln39 min
May 24, 6:47 PM CDTSevere Thunderstorm WarningLIXIberville, West Baton Rouge28 min
May 24, 7:10 PM CDTSevere Thunderstorm WarningJANAdams, Franklin, Jefferson50 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

Jackson, MS (KJAN), launched 12:00Z, 6.8 hours before the alert went out and 169 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, Jackson, MS at 12:00Z on 2015-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 357 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, Jackson, MS at 12:00Z on 2015-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 square meters per square second.1939Sfc1 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
357 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
748 m above ground
0-6 km bulk shear
0 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
0 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

148 
WWUS20 KWNS 241847
SEL4  
SPC WW 241847
ARZ000-LAZ000-MSZ000-CWZ000-250100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 204
NWS STORM PREDICTION CENTER NORMAN OK
150 PM CDT SUN MAY 24 2015

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  FAR SOUTHEAST ARKANSAS
  MUCH OF LOUISIANA
  SOUTHERN AND WESTERN MISSISSIPPI
  COASTAL WATERS

* EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 150 PM UNTIL
  800 PM CDT.

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

SUMMARY...A BROKEN LINE OF STRONG THUNDERSTORMS CONTINUES MOVING
GRADUALLY EASTWARD ACROSS WESTERN LOUISIANA...WITH OTHER/MORE
ISOLATED STORMS DEVELOPING/SPREADING NORTH AHEAD OF THE
AFOREMENTIONED BAND.  RISK FOR LOCALLY DAMAGING WINDS AND A COUPLE
OF TORNADOES WILL LIKELY EVOLVE WITH A FEW OF THE STRONGER UPDRAFTS
THROUGH THIS AFTERNOON.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 100 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 35 MILES SOUTHWEST OF
ALEXANDRIA LOUISIANA TO 50 MILES NORTH NORTHEAST OF SLIDELL
LOUISIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).

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...CONTINUE...WW 202...WW 203...

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 500.
MEAN STORM MOTION VECTOR 20035.


...GOSS

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 24, 12:05 PM CDTMesoscale DiscussionSPCAllen, Bienville, Bossier, Caddo, Caldwell, Claiborne and 14 more115 min
May 24, 12:34 PM CDTTornado WatchSPCBienville, Bossier, Caddo, Claiborne, Jackson, Lincoln and 3 more6 hr
May 24, 5:03 PM CDTMesoscale DiscussionSPCAscension, Assumption, Avoyelles, Catahoula, Concordia, East Baton Rouge and 30 more117 min
May 24, 4:14 PM CDTTornado WatchSPCAlcorn, Benton, Calhoun, Chickasaw, Coahoma, DeSoto and 16 more8 hr
May 24, 6:04 PM CDTMesoscale DiscussionSPCBenton, Chickasaw, DeSoto, Lafayette, Marshall, Panola and 6 more116 min

Nearby

Tornado Watches in Louisiana, 2015Tornado Watches in Mississippi, 2015Every tornado watch in 2015

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.