Alert archive / Alabama / Tornado Watches in 2018

Tornado Watch 420

November 1, 201838 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida

The Storm Prediction Center issued this tornado watch at Nov 1, 2018, 5:27 AM CDT for 38 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Nov 1, 2018, 5:27 AM CDT (10:27 UTC)
Expired
Nov 1, 2018, 12:27 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 41 counties

Autauga County, AL, Baldwin County, AL, Bibb County, AL, Butler County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Colbert County, AL, Conecuh County, AL, Coosa County, AL, Covington County, AL, Crenshaw County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Lowndes County, AL, Marengo County, AL, Marion County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Washington County, AL, Wilcox County, AL, Winston County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL

The radar

The Birmingham radar (KBMX), 154 km from the middle of the area, began a volume at 10:32 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
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
40%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Nov 1, 5:44 AM CDTSevere Thunderstorm WarningHUNColbert, Franklin, Lauderdale31 min
Nov 1, 5:57 AM CDTTornado Warning Tornado observedHUNFranklin18 min
Nov 1, 6:08 AM CDTSevere Thunderstorm WarningHUNColbert, Franklin, Lauderdale, Lawrence52 min
Nov 1, 6:14 AM CDTTornado Warning Tornado observedHUNColbert, Franklin9 min
Nov 1, 6:19 AM CDTSevere Thunderstorm WarningMOBMobile, Washington41 min
Nov 1, 6:29 AM CDTTornado WarningMOBWashington46 min
Nov 1, 6:33 AM CDTSevere Thunderstorm WarningMOBChoctaw, Clarke, Washington42 min
Nov 1, 6:50 AM CDTSevere Thunderstorm WarningMOBBaldwin, Clarke, Mobile, Washington40 min
Nov 1, 7:02 AM CDTTornado WarningMOBChoctaw, Clarke31 min
Nov 1, 7:03 AM CDTTornado WarningMOBBaldwin, Mobile27 min
Nov 1, 7:15 AM CDTSevere Thunderstorm WarningMOBChoctaw, Clarke, Monroe, Washington45 min
Nov 1, 7:25 AM CDTTornado WarningMOBBaldwin35 min
Nov 1, 7:30 AM CDTSevere Thunderstorm WarningMOBBaldwin, Clarke, Escambia, Mobile, Monroe45 min
Nov 1, 8:00 AM CDTSevere Thunderstorm WarningMOBClarke, Conecuh, Monroe, Wilcox45 min
Nov 1, 8:03 AM CDTSevere Thunderstorm WarningMOBEscambia42 min
Nov 1, 8:07 AM CDTSevere Thunderstorm WarningMOBBaldwin38 min
Nov 1, 8:39 AM CDTSevere Thunderstorm WarningMOBConecuh, Covington, Escambia51 min
Nov 1, 9:20 AM CDTSevere Thunderstorm WarningMOBCovington, Crenshaw40 min
Nov 1, 9:55 AM CDTSevere Thunderstorm WarningMOBCovington, Crenshaw35 min
Nov 1, 10:18 AM CDTSevere Thunderstorm WarningMOBEscambia, Santa Rosa42 min
Nov 1, 10:43 AM CDTSevere Thunderstorm WarningMOBOkaloosa, Santa Rosa47 min
Nov 1, 11:29 AM CDTSevere Thunderstorm WarningMOBOkaloosa31 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

Birmingham, AL (KBMX), launched 00:00Z, 10.5 hours before the alert went out and 155 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, Birmingham, AL at 00:00Z on 2018-11-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 56 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, Birmingham, AL at 00:00Z on 2018-11-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 125 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
56 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
1238 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
125 m²/s²
0-3 km storm-relative helicity
198 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 1, 4:30 AM CDTMesoscale DiscussionSPCAutauga, Baldwin, Bibb, Butler, Chilton, Choctaw and 23 more2 hr
Nov 1, 7:50 AM CDTMesoscale DiscussionSPCAutauga, Baldwin, Bibb, Butler, Chilton, Clarke and 22 more115 min
Nov 1, 8:43 AM CDTMesoscale DiscussionSPCCoffee, Dale, Geneva, Henry, Houston2 hr
Nov 1, 9:40 AM CDTSevere Thunderstorm WatchSPCBarbour, Bullock, Coffee, Dale, Geneva, Henry and 3 more4 hr
Nov 1, 12:03 PM CDTMesoscale DiscussionSPCChambers, Cherokee, Cleburne, DeKalb, Henry, Houston and 3 more117 min
Oct 31, 7:04 PM CDTMesoscale DiscussionSPCBenton, Marshall116 min
Oct 31, 8:14 PM CDTTornado WatchSPCAdams, Wilkinson8 hr
Oct 31, 10:01 PM CDTMesoscale DiscussionSPCAdams, Amite, Attala, Calhoun, Carroll, Claiborne and 32 more89 min
Oct 31, 11:07 PM CDTTornado WatchSPCAmite, Attala, Bolivar, Calhoun, Carroll, Choctaw and 58 more9 hr
Nov 1, 1:19 AM CDTMesoscale DiscussionSPCAdams, Amite, Attala, Bolivar, Carroll, Claiborne and 31 more116 min
Nov 1, 1:41 AM CDTMesoscale DiscussionSPCAlcorn, Benton, DeSoto, Marshall, Prentiss, Tate and 3 more3 hr

Nearby

Tornado Watches in Alabama, 2018Tornado Watches in Florida, 2018Every tornado watch in 2018

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.