Alert archive / Florida / Tornado Watches in 2021

Tornado Watch 10

February 18, 2021Geneva County, Houston County, Alabama; 13 counties in Florida; 8 counties in Georgia

The Storm Prediction Center issued this tornado watch at Feb 18, 2021, 1:49 AM CST for Geneva County, Houston County, Alabama; 13 counties in Florida; 8 counties in Georgia. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Feb 18, 2021, 1:49 AM CST (07:49 UTC)
Expired
Feb 18, 2021, 7:47 AM CST
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 23 counties

Geneva County, AL, Houston County, AL, Bay County, FL, Calhoun County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Leon County, FL, Liberty County, FL, Okaloosa County, FL, Wakulla County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Calhoun County, GA, Decatur County, GA, Early County, GA, Grady County, GA, Miller County, GA, Mitchell County, GA, Seminole County, GA

The radar

The Eglin Afb radar (KEVX), 47 km from the middle of the area, began a volume at 07:51 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
50%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Feb 18, 1:49 AM CSTSevere Thunderstorm WarningMOBOkaloosa, Santa Rosa41 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

Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 7.8 hours before the alert went out and 110 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, Tallahassee Rgnl, FL at 00:00Z on 2021-02-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tallahassee Rgnl, FL at 00:00Z on 2021-02-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 238 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1835 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
238 m²/s²
0-3 km storm-relative helicity
546 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

762 
WWUS20 KWNS 180747
SEL0  
SPC WW 180747
ALZ000-FLZ000-GAZ000-CWZ000-181400-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 10
NWS Storm Prediction Center Norman OK
150 AM CST Thu Feb 18 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Extreme southeastern Alabama
  Florida Panhandle
  Southwestern Georgia
  Coastal Waters

* Effective this Thursday morning from 150 AM until 800 AM CST.

* Primary threats include...
  A couple tornadoes possible
  Isolated damaging wind gusts to 70 mph possible

SUMMARY...A severe-thunderstorm threat, including damaging gusts and
a couple tornadoes possible, will spread inland across the watch
area near and south of a warm front, through early morning.

The tornado watch area is approximately along and 55 statute miles
either side of a line from 25 miles southwest of Panama City FL to
50 miles north of Tallahassee FL. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU0).

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.

&&

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1 inch. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 23030.

...Edwards

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 17, 10:18 PM CSTMesoscale DiscussionSPCBay, Calhoun, Escambia, Gulf, Okaloosa, Santa Rosa and 2 more2 hr
Feb 18, 4:54 AM CSTMesoscale DiscussionSPCBay, Gulf2 hr
Feb 18, 7:09 AM CSTMesoscale DiscussionSPCBay, Calhoun, Franklin, Gadsden, Gulf, Jackson and 4 more2 hr
Feb 18, 7:45 AM CSTTornado WatchSPCBay, Calhoun, Franklin, Gadsden, Gulf, Jackson and 6 more7 hr
Feb 18, 10:35 AM CSTMesoscale DiscussionSPCGadsden, Jefferson, Leon, Liberty, Wakulla115 min
Feb 18, 12:43 PM CSTMesoscale DiscussionSPCJefferson, Madison, Taylor92 min

Nearby

Tornado Watches in Florida, 2021Tornado Watches in Georgia, 2021Tornado Watches in Alabama, 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.