Alert archive / Louisiana / Tornado Watches in 2006

Tornado Watch 841

October 27, 20064 counties in Alabama; 12 parishes in Louisiana; 12 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Oct 27, 2006, 6:34 AM CDT for 4 counties in Alabama; 12 parishes in Louisiana; 12 counties in Mississippi. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Oct 27, 2006, 6:34 AM CDT (11:34 UTC)
Expired
Oct 27, 2006, 2:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 28 counties

Baldwin County, AL, Clarke County, AL, Mobile County, AL, Washington County, AL, Jefferson Parish, LA, Lafourche Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Walthall 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
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 27, 6:45 AM CDTTornado WarningLIXTangipahoa30 min
Oct 27, 6:46 AM CDTTornado WarningJANMarion44 min
Oct 27, 6:53 AM CDTSevere Thunderstorm WarningLIXSaint Tammany67 min
Oct 27, 6:59 AM CDTSevere Thunderstorm WarningLIXWashington61 min
Oct 27, 7:09 AM CDTSevere Thunderstorm WarningLIXJefferson, Lafourche, Saint Charles66 min
Oct 27, 7:17 AM CDTTornado WarningLIXSaint Tammany28 min
Oct 27, 7:34 AM CDTTornado WarningJANLamar34 min
Oct 27, 7:37 AM CDTTornado WarningLIXWashington23 min
Oct 27, 7:51 AM CDTTornado WarningJANForrest39 min
Oct 27, 7:54 AM CDTSevere Thunderstorm WarningLIXHancock36 min
Oct 27, 8:01 AM CDTTornado WarningLIXPearl River14 min
Oct 27, 8:07 AM CDTTornado WarningLIXJefferson, Plaquemines53 min
Oct 27, 8:21 AM CDTSevere Thunderstorm WarningLIXHarrison54 min
Oct 27, 8:23 AM CDTSevere Thunderstorm WarningMOBGeorge, Stone52 min
Oct 27, 8:29 AM CDTSevere Thunderstorm WarningMOBGreene, Perry31 min
Oct 27, 9:03 AM CDTSevere Thunderstorm WarningMOBMobile, Washington42 min
Oct 27, 9:08 AM CDTSevere Thunderstorm WarningLIXPlaquemines37 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, 11.6 hours before the alert went out and 23 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 00:00Z on 2006-10-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 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 00:00Z on 2006-10-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 267 square meters per square second.193958Sfc1 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
4 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
820 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
267 m²/s²
0-3 km storm-relative helicity
345 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 27, 9:14 AM CDTMesoscale DiscussionSPCBaldwin, Escambia, Mobile2 hr
Oct 27, 2:20 PM CDTMesoscale DiscussionSPCCullman, Fayette, Greene, Lauderdale, Lawrence, Limestone and 5 more85 min
Oct 26, 9:05 PM CDTMesoscale DiscussionSPCBossier, Caddo, De Soto, Webster115 min
Oct 26, 11:52 PM CDTMesoscale DiscussionSPCBossier, Caddo, De Soto, Webster83 min
Oct 27, 5:43 AM CDTMesoscale DiscussionSPCAscension, Assumption, Iberville, Jefferson, Lafourche, Livingston and 8 more92 min

Nearby

Tornado Watches in Louisiana, 2006Tornado Watches in Mississippi, 2006Tornado Watches in Alabama, 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.