Alert archive / Louisiana / Tornado Watches in 2006

Tornado Watch 890

December 30, 200625 parishes in Louisiana; Amite County, Wilkinson County, Mississippi

The Storm Prediction Center issued this tornado watch at Dec 30, 2006, 5:43 AM CST for 25 parishes in Louisiana; Amite County, Wilkinson County, Mississippi. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Dec 30, 2006, 5:43 AM CST (11:43 UTC)
Expired
Dec 30, 2006, 12:00 PM CST
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 27 counties

Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Cameron Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Livingston Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Wilkinson County, MS

The radar

The Lake Charles radar (KLCH), 108 km from the middle of the area, began a volume at 11:46 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

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
20%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
20%
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
40%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Dec 30, 6:59 AM CSTSevere Thunderstorm WarningLCHAcadia, Iberia, Lafayette, Saint Landry, Saint Martin, Vermilion46 min
Dec 30, 7:14 AM CSTSevere Thunderstorm WarningLIXIberville, Pointe Coupee, West Feliciana61 min
Dec 30, 7:43 AM CSTSevere Thunderstorm WarningLCHIberia, Saint Landry, Saint Martin, St. Mary, Vermilion62 min
Dec 30, 7:58 AM CSTTornado WarningLCHIberia, Saint Martin32 min
Dec 30, 8:34 AM CSTTornado WarningLIXPointe Coupee26 min
Dec 30, 10:04 AM CSTTornado WarningLIXEast Baton Rouge26 min
Dec 30, 10:23 AM CSTTornado WarningLIXEast Feliciana37 min
Dec 30, 10:39 AM CSTFlash Flood WarningLIXIberville, Pointe Coupee, West Baton Rouge2 hr
Dec 30, 10:44 AM CSTFlash Flood WarningLIXEast Baton Rouge2 hr
Dec 30, 11:05 AM CSTSevere Thunderstorm WarningLCHSt. Mary40 min
Dec 30, 11:28 AM CSTTornado WarningLIXSaint Helena, Tangipahoa32 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

Lake Charles Mun, LA (KLCH), launched 00:00Z, 11.7 hours before the alert went out and 106 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, Lake Charles Mun, LA at 00:00Z on 2006-12-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1234 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, Lake Charles Mun, LA at 00:00Z on 2006-12-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 312 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
1234 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
528 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
312 m²/s²
0-3 km storm-relative helicity
410 m²/s²
Significant tornado parameter
2.5
Supercell composite
17.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 29, 7:52 PM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 18 more53 min
Dec 29, 8:19 PM CSTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 23 more10 hr
Dec 29, 11:41 PM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 24 more94 min
Dec 30, 3:14 AM CSTMesoscale DiscussionSPCAcadia, Allen, Assumption, Avoyelles, Beauregard, Bienville and 30 more91 min
Dec 30, 7:49 AM CSTMesoscale DiscussionSPCJefferson, Orleans, Plaquemines, Saint Bernard, Saint Charles, Saint John the Baptist and 3 more86 min
Dec 30, 8:43 AM CSTTornado WatchSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 5 more5 hr
Dec 30, 10:22 AM CSTMesoscale DiscussionSPCAscension, Assumption, Jefferson, Lafourche, Livingston, Orleans and 9 more83 min
Dec 30, 1:13 PM CSTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Saint Bernard, Saint Charles, Saint Tammany62 min
Dec 30, 1:30 PM CSTTornado WatchSPCJefferson, Lafourche, Livingston, Orleans, Plaquemines, Saint Bernard and 6 more7 hr
Dec 30, 5:45 PM CSTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 4 more60 min

Nearby

Tornado Watches in Louisiana, 2006Tornado Watches in Mississippi, 2006Every tornado watch in 2006

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; radar from the NEXRAD Level II archive.