Alert archive / Alabama / Tornado Watches in 2021

Tornado Watch 543

October 27, 20214 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida

The Storm Prediction Center issued this tornado watch at Oct 27, 2021, 7:21 PM CDT for 4 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
Oct 27, 2021, 7:21 PM CDT (00:21 UTC)
Expired
Oct 28, 2021, 2:00 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
55 kt

Counties Baldwin County, AL, Escambia County, AL, Mobile County, AL, Washington County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL

The radar

The Mobile radar (KMOB), 66 km from the middle of the area, began a volume at 00:20 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
40%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 27, 8:53 PM CDTTornado WarningMOBMobile35 min
Oct 27, 9:08 PM CDTTornado WarningMOBMobile25 min
Oct 27, 11:49 PM CDTSevere Thunderstorm WarningMOBOkaloosa41 min
Oct 28, 12:31 AM CDTFlash Flood WarningMOBOkaloosa5 hr

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, 0.4 hours before the alert went out and 214 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 2021-10-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1392 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°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 2021-10-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 216 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
1392 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
520 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
216 m²/s²
0-3 km storm-relative helicity
253 m²/s²
Significant tornado parameter
1.5
Supercell composite
8.0

Open this sounding in Storm Lab

The text

As transmitted.

052 
WWUS20 KWNS 280018
SEL3  
SPC WW 280018
ALZ000-FLZ000-CWZ000-280600-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 543
NWS Storm Prediction Center Norman OK
720 PM CDT Wed Oct 27 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southwest Alabama
  Western Florida Panhandle
  Coastal Waters

* Effective this Wednesday night and Thursday morning from 720 PM
  until 100 AM CDT.

* Primary threats include...
  A couple tornadoes possible
  Isolated damaging wind gusts to 65 mph possible

SUMMARY...A steadily progressing squall line should continue to
shift across the central Gulf Coast region into the early overnight.
A couple tornadoes and locally damaging winds will remain possible.

The tornado watch area is approximately along and 35 statute miles
north and south of a line from 15 miles north northwest of Mobile AL
to 15 miles south southeast of Crestview FL. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU3).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 542...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 0.5 inches. Extreme turbulence and surface wind
gusts to 55 knots. A few cumulonimbi with maximum tops to 550. Mean
storm motion vector 23035.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 27, 9:08 PM CDTMesoscale DiscussionSPCBaldwin, Escambia, Mobile97 min
Oct 27, 10:22 PM CDTMesoscale DiscussionSPCBay, Franklin, Gulf, Walton2 hr
Oct 27, 11:21 PM CDTTornado WatchSPCBay, Calhoun, Franklin, Gulf, Liberty, Wakulla and 2 more6 hr
Oct 28, 7:12 AM CDTMesoscale DiscussionSPCAlachua, Bradford, Citrus, Dixie, Gilchrist, Hernando and 7 more2 hr
Oct 28, 8:00 AM CDTTornado WatchSPCAlachua, Baker, Bradford, Brevard, Charlotte, Citrus and 35 more10 hr
Oct 28, 10:51 AM CDTMesoscale DiscussionSPCCharlotte, DeSoto, Flagler, Hardee, Highlands, Hillsborough and 11 more114 min
Oct 28, 1:08 PM CDTMesoscale DiscussionSPCCharlotte, DeSoto, Flagler, Hardee, Lake, Manatee and 3 more97 min
Oct 28, 3:11 PM CDTMesoscale DiscussionSPCBrevard, Charlotte, DeSoto, Glades, Highlands, Indian River and 2 more94 min

Nearby

Tornado Watches in Alabama, 2021Tornado Watches in Florida, 2021Every tornado watch in 2021

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.