Alert archive / Louisiana / Tornado Watches in 2014

Tornado Watch 560

December 23, 20144 counties in Alabama; 47 parishes in Louisiana; 40 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Dec 23, 2014, 9:30 AM CST for 4 counties in Alabama; 47 parishes in Louisiana; 40 counties in Mississippi. It was in force for 11 hr.

The area

The outline as issued.

The facts

Issued: Dec 23, 2014, 9:30 AM CST (15:30 UTC)
Expired: Dec 23, 2014, 8:00 PM CST
In force: 11 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 91 counties

Baldwin County, AL, Choctaw County, AL, Mobile County, AL, Washington County, AL, Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge 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, 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, Vernon Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Hinds County, MS, Jackson County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Walthall County, MS, Warren County, MS, Wayne 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: 70%
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: 30%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Dec 23, 9:40 AM CST	Severe Thunderstorm Warning	LCH	Avoyelles, Saint Landry	65 min
Dec 23, 9:43 AM CST	Severe Thunderstorm Warning	LIX	Saint Helena, Tangipahoa	47 min
Dec 23, 9:52 AM CST	Severe Thunderstorm Warning	LCH	Lafayette, Saint Landry, Saint Martin	38 min
Dec 23, 9:54 AM CST	Severe Thunderstorm Warning	LCH	Allen, Beauregard, Calcasieu	51 min
Dec 23, 10:11 AM CST	Severe Thunderstorm Warning	LCH	Avoyelles	64 min
Dec 23, 10:17 AM CST	Severe Thunderstorm Warning	LIX	Pointe Coupee, West Feliciana	43 min
Dec 23, 10:20 AM CST	Severe Thunderstorm Warning	LIX	Iberville, Pointe Coupee, West Feliciana	25 min
Dec 23, 10:25 AM CST	Severe Thunderstorm Warning	LCH	Allen, Beauregard, Rapides, Vernon	50 min
Dec 23, 10:29 AM CST	Tornado Warning	LCH	Allen, Beauregard	31 min
Dec 23, 10:31 AM CST	Severe Thunderstorm Warning	LIX	Pike, Walthall	29 min
Dec 23, 10:33 AM CST	Tornado Warning	LIX	West Feliciana	27 min
Dec 23, 10:39 AM CST	Severe Thunderstorm Warning	JAN	Copiah, Lincoln	23 min
Dec 23, 10:42 AM CST	Severe Thunderstorm Warning	LIX	East Feliciana, Pointe Coupee, West Feliciana	48 min
Dec 23, 10:51 AM CST	Severe Thunderstorm Warning	JAN	Jefferson Davis, Lawrence	39 min
Dec 23, 10:52 AM CST	Tornado Warning	LIX	East Baton Rouge, East Feliciana, Saint Helena, West Feliciana	23 min
Dec 23, 10:53 AM CST	Severe Thunderstorm Warning	JAN	Catahoula, Concordia, Tensas	52 min
Dec 23, 11:01 AM CST	Severe Thunderstorm Warning	LIX	Amite	29 min
Dec 23, 11:10 AM CST	Severe Thunderstorm Warning	JAN	Franklin, Lincoln	45 min
Dec 23, 11:12 AM CST	Severe Thunderstorm Warning	JAN	Simpson	33 min
Dec 23, 11:15 AM CST	Severe Thunderstorm Warning	LCH	Evangeline, Rapides	45 min
Dec 23, 11:20 AM CST	Severe Thunderstorm Warning	JAN	Catahoula, Franklin, Tensas	40 min
Dec 23, 11:25 AM CST	Severe Thunderstorm Warning	JAN	Clarke, Jasper, Lauderdale, Newton	36 min
Dec 23, 11:28 AM CST	Tornado Warning	LIX	East Feliciana	47 min
Dec 23, 11:32 AM CST	Severe Thunderstorm Warning	LCH	Cameron	36 min
Dec 23, 11:48 AM CST	Severe Thunderstorm Warning	JAN	Madison	30 min
Dec 23, 11:52 AM CST	Severe Thunderstorm Warning	LCH	Avoyelles, Rapides	20 min
Dec 23, 11:57 AM CST	Severe Thunderstorm Warning	JAN	Kemper	35 min
Dec 23, 12:05 PM CST	Severe Thunderstorm Warning	LCH	Acadia, Jefferson Davis	25 min
Dec 23, 12:09 PM CST	Severe Thunderstorm Warning	JAN	Lawrence, Lincoln	66 min
Dec 23, 12:30 PM CST	Tornado Warning	JAN	Lawrence, Lincoln	35 min
Dec 23, 12:31 PM CST	Severe Thunderstorm Warning	JAN	Concordia	37 min
Dec 23, 12:52 PM CST	Severe Thunderstorm Warning	JAN	Copiah, Simpson	38 min
Dec 23, 12:55 PM CST	Severe Thunderstorm Warning	LIX	Livingston, Saint Helena, Tangipahoa, Washington	50 min
Dec 23, 12:59 PM CST	Severe Thunderstorm Warning	LCH	Lafayette, Saint Landry, Saint Martin	25 min
Dec 23, 1:02 PM CST	Tornado Warning	LIX	Livingston, Saint Helena, Tangipahoa	28 min
Dec 23, 1:02 PM CST	Severe Thunderstorm Warning	JAN	Claiborne, Jefferson	43 min
Dec 23, 1:22 PM CST	Tornado Warning	LIX	Tangipahoa, Washington	23 min
Dec 23, 1:26 PM CST	Tornado Warning	JAN	Simpson, Smith	34 min
Dec 23, 1:38 PM CST	Tornado Warning	LIX	Washington	37 min
Dec 23, 1:53 PM CST	Severe Thunderstorm Warning	JAN	Copiah, Lawrence, Lincoln, Simpson	49 min
Dec 23, 1:57 PM CST	Tornado Warning	JAN	Marion	43 min
Dec 23, 2:33 PM CST	Tornado Warning Tornado observed	JAN	Covington, Forrest, Jefferson Davis, Jones, Lamar	57 min
Dec 23, 2:52 PM CST	Severe Thunderstorm Warning	JAN	Clarke, Jasper	53 min
Dec 23, 3:00 PM CST	Flash Flood Warning	JAN	Covington, Jefferson Davis, Lamar, Marion	3 hr
Dec 23, 3:20 PM CST	Tornado Warning	JAN	Jasper, Jones	40 min
Dec 23, 3:37 PM CST	Severe Thunderstorm Warning	JAN	Lauderdale	38 min
Dec 23, 3:37 PM CST	Severe Thunderstorm Warning	JAN	Jones	28 min
Dec 23, 3:38 PM CST	Severe Thunderstorm Warning	MOB	Greene, Perry, Wayne	51 min
Dec 23, 3:42 PM CST	Tornado Warning	LIX	Ascension, Assumption, Saint James	48 min
Dec 23, 3:49 PM CST	Tornado Warning	JAN	Clarke	56 min
Dec 23, 3:51 PM CST	Flash Flood Warning	JAN	Jasper, Jones	3 hr
Dec 23, 3:59 PM CST	Tornado Warning	MOB	Wayne	31 min
Dec 23, 4:08 PM CST	Severe Thunderstorm Warning	LIX	Saint James, Saint John the Baptist	30 min
Dec 23, 4:09 PM CST	Severe Thunderstorm Warning	LIX	Lafourche, Saint Charles, Saint John the Baptist	35 min
Dec 23, 4:09 PM CST	Severe Thunderstorm Warning	JAN	Lauderdale	51 min
Dec 23, 4:19 PM CST	Severe Thunderstorm Warning	MOB	Choctaw	32 min
Dec 23, 4:23 PM CST	Tornado Warning	LIX	Saint John the Baptist	22 min
Dec 23, 4:25 PM CST	Tornado Warning	JAN	Lauderdale	35 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, 3.5 hours before the alert went out and 117 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 266 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 619 m above ground
0-6 km bulk shear: 71 kt
0-1 km storm-relative helicity: 107 m²/s²
0-3 km storm-relative helicity: 156 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.4

Open this sounding in Storm Lab

The text

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

363 
WWUS20 KWNS 231539
SEL0  
SPC WW 231539
ALZ000-LAZ000-MSZ000-TXZ000-CWZ000-240000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 560
NWS STORM PREDICTION CENTER NORMAN OK
930 AM CST TUE DEC 23 2014

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  SOUTHWEST ALABAMA
  LOUISIANA
  SOUTHERN AND CENTRAL MISSISSIPPI
  FAR SOUTHEAST TEXAS
  COASTAL WATERS

* EFFECTIVE THIS TUESDAY MORNING AND EVENING FROM 930 AM UNTIL
  600 PM CST.

* PRIMARY THREATS INCLUDE...
  A FEW TORNADOES POSSIBLE
  SCATTERED DAMAGING WIND GUSTS TO 70 MPH LIKELY
  ISOLATED VERY LARGE HAIL EVENTS TO 2 INCHES IN DIAMETER POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 100 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 65 MILES NORTH NORTHEAST OF
MOBILE ALABAMA TO 30 MILES WEST OF LAKE CHARLES LOUISIANA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU0).

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.

&&

DISCUSSION...TSTMS EXPECTED TO GRADUALLY INCREASE IN
COVERAGE/STRENGTH OVER WW AREA THROUGH LATER TODAY AS REGION OF
LOW-LVL MOISTENING IS GLANCED BY LEAD IMPULSE /NOW IN CNTRL TX/
ASSOCIATED WITH BROAD...CNTRL U.S. UPR TROUGH. LOW-LVL FORCING WILL
REMAIN WEAK/FRAGMENTED...PRIMARILY ALONG NUMEROUS SSW-NNE CONFLUENCE
AXES. AT THE SAME TIME...LARGE-SCALE FORCING FOR ASCENT WILL BE
MODEST.  BUT COUPLED WITH FAIRLY EXPANSIVE AREA OF RETURNING
MOISTURE BENEATH A BROAD EML AND WITH AMPLE SWLY DEEP SHEAR FOR
SUPERCELLS...OVERALL SETUP YIELDS A SIZABLE AREA WITH A
COMPARATIVELY UNFOCUSED...BUT APPRECIABLE...RISK FOR OCCASIONAL
TORNADOES...SVR HAIL...AND LOCALLY DMGG WIND.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 23035.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 23, 3:45 AM CST	Mesoscale Discussion	SPC	Baldwin	2 hr
Dec 23, 7:39 AM CST	Mesoscale Discussion	SPC	Choctaw, Greene, Pickens, Sumter	3 hr
Dec 23, 7:40 AM CST	Mesoscale Discussion	SPC	Baldwin, Butler, Clarke, Coffee, Conecuh, Covington and 8 more	2 hr
Dec 23, 11:33 AM CST	Mesoscale Discussion	SPC	Choctaw, Greene, Mobile, Sumter, Washington	87 min
Dec 23, 2:06 PM CST	Mesoscale Discussion	SPC	Autauga, Baldwin, Barbour, Bibb, Bullock, Butler and 32 more	114 min
Dec 23, 2:47 PM CST	Tornado Watch	SPC	Autauga, Barbour, Bibb, Bullock, Butler, Chambers and 34 more	8 hr
Dec 23, 2:57 PM CST	Mesoscale Discussion	SPC	Choctaw, Greene, Mobile, Sumter, Washington	93 min
Dec 23, 4:59 PM CST	Mesoscale Discussion	SPC	Baldwin, Mobile, Washington	61 min
Dec 23, 4:19 AM CST	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 20 more	116 min

Nearby

Tornado Watches in Louisiana, 2014 Tornado Watches in Mississippi, 2014 Tornado Watches in Alabama, 2014 Every tornado watch in 2014

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.