Alert archive / Alabama / Tornado Watches in 2015

Tornado Watch 529

October 31, 20159 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida

The Storm Prediction Center issued this tornado watch at Oct 31, 2015, 4:57 PM CDT for 9 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Oct 31, 2015, 4:57 PM CDT (21:57 UTC)
Expired
Oct 31, 2015, 9:09 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt

Counties Baldwin County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Escambia County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL

The radar

The Mobile radar (KMOB), 71 km from the middle of the area, began a volume at 22:00 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
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 31, 5:04 PM CDTTornado WarningMOBChoctaw31 min
Oct 31, 5:23 PM CDTSevere Thunderstorm WarningMOBChoctaw, Clarke52 min
Oct 31, 5:26 PM CDTSevere Thunderstorm WarningMOBBaldwin, Choctaw, Clarke, Mobile, Washington1 min
Oct 31, 5:28 PM CDTSevere Thunderstorm WarningMOBChoctaw, Washington47 min
Oct 31, 5:31 PM CDTSevere Thunderstorm WarningMOBWashington44 min
Oct 31, 6:10 PM CDTSevere Thunderstorm WarningMOBChoctaw, Clarke35 min
Oct 31, 6:11 PM CDTSevere Thunderstorm WarningMOBChoctaw, Clarke, Mobile, Washington49 min
Oct 31, 6:12 PM CDTSevere Thunderstorm WarningMOBMobile48 min
Oct 31, 7:00 PM CDTSevere Thunderstorm WarningMOBBaldwin, Mobile45 min
Oct 31, 7:26 PM CDTSevere Thunderstorm WarningMOBBaldwin, Mobile49 min
Oct 31, 7:33 PM CDTSevere Thunderstorm WarningMOBClarke, Wilcox15 min
Oct 31, 8:24 PM CDTSevere Thunderstorm WarningMOBWilcox36 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 12:00Z, 10.0 hours before the alert went out and 218 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 12:00Z on 2015-10-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 12:00Z on 2015-10-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 292 square meters per square second.19395878Sfc1 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
847 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
292 m²/s²
0-3 km storm-relative helicity
361 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
Oct 31, 4:35 PM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 9 more115 min

Nearby

Tornado Watches in Alabama, 2015Tornado Watches in Florida, 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.