Alert archive / Mississippi / Tornado Watches in 2015

Tornado Watch 551

November 18, 201510 counties in Alabama; 5 parishes in Louisiana; 16 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Nov 18, 2015, 2:49 AM CST for 10 counties in Alabama; 5 parishes in Louisiana; 16 counties in Mississippi. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Nov 18, 2015, 2:49 AM CST (08:49 UTC)
Expired
Nov 18, 2015, 9:00 AM CST
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 31 counties

Baldwin County, AL, Choctaw County, AL, Clarke County, AL, Greene County, AL, Hale County, AL, Marengo County, AL, Mobile County, AL, Pickens County, AL, Sumter County, AL, Washington County, AL, Jefferson Parish, LA, Lafourche Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Clarke County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jones County, MS, Kemper County, MS, Lauderdale County, MS, Lowndes County, MS, Noxubee County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 112 km from the middle of the area, began a volume at 08:51 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
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Nov 18, 3:26 AM CSTSevere Thunderstorm WarningJANLowndes, Noxubee64 min
Nov 18, 3:37 AM CSTSevere Thunderstorm WarningMOBBaldwin, Escambia38 min
Nov 18, 3:38 AM CSTTornado WarningMOBBaldwin, Escambia13 min
Nov 18, 3:41 AM CSTSevere Thunderstorm WarningJANLowndes47 min
Nov 18, 3:55 AM CSTTornado WarningJANLowndes24 min
Nov 18, 4:13 AM CSTSevere Thunderstorm WarningJANKemper, Noxubee29 min
Nov 18, 4:27 AM CSTSevere Thunderstorm WarningBMXPickens, Sumter48 min
Nov 18, 6:22 AM CSTTornado WarningMOBWayne23 min
Nov 18, 8:23 AM CSTSevere Thunderstorm WarningMOBMobile52 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 00:00Z, 8.8 hours before the alert went out and 157 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 00:00Z on 2015-11-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 107 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2015-11-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 309 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
107 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
916 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
309 m²/s²
0-3 km storm-relative helicity
502 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.6

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 18, 1:14 AM CSTMesoscale DiscussionSPCChoctaw, Clarke, Fayette, Greene, Hale, Lamar and 8 more2 hr
Nov 18, 5:21 AM CSTMesoscale DiscussionSPCBaldwin, Choctaw, Clarke, Dallas, Fayette, Greene and 9 more114 min
Nov 18, 7:22 AM CSTMesoscale DiscussionSPCAutauga, Baldwin, Bibb, Butler, Chilton, Clarke and 14 more83 min
Nov 18, 8:25 AM CSTTornado WatchSPCAutauga, Baldwin, Barbour, Bullock, Butler, Clarke and 22 more8 hr
Nov 18, 10:51 AM CSTMesoscale DiscussionSPCAutauga, Baldwin, Barbour, Bullock, Butler, Coffee and 17 more114 min
Nov 18, 1:39 PM CSTMesoscale DiscussionSPCBarbour, Coffee, Covington, Crenshaw, Dale, Geneva and 3 more2 hr
Nov 18, 2:16 PM CSTTornado WatchSPCCoffee, Dale, Geneva, Henry, Houston6 hr
Nov 17, 6:53 PM CSTMesoscale DiscussionSPCConcordia97 min
Nov 17, 7:45 PM CSTTornado WatchSPCAscension, Assumption, Concordia, East Baton Rouge, East Feliciana, Iberia and 25 more7 hr
Nov 17, 11:11 PM CSTMesoscale DiscussionSPCLivingston, Saint John the Baptist, Saint Tammany, Tangipahoa, Washington94 min

Nearby

Tornado Watches in Mississippi, 2015Tornado Watches in Alabama, 2015Tornado Watches in Louisiana, 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; radar from the NEXRAD Level II archive.