Alert archive / Alabama / Tornado Watches in 2018

Tornado Watch 56

April 22, 201814 counties in Alabama; 12 counties in Florida; 12 counties in Georgia

The Storm Prediction Center issued this tornado watch at Apr 22, 2018, 2:55 PM CDT for 14 counties in Alabama; 12 counties in Florida; 12 counties in Georgia. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Apr 22, 2018, 2:55 PM CDT (19:55 UTC)
Expired
Apr 22, 2018, 10:56 PM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 38 counties

Barbour County, AL, Bullock County, AL, Coffee County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Lee County, AL, Macon County, AL, Montgomery County, AL, Pike County, AL, Russell County, AL, Bay County, FL, Calhoun County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Liberty County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Calhoun County, GA, Clay County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Lee County, GA, Miller County, GA, Quitman County, GA, Randolph County, GA, Seminole County, GA, Terrell County, GA

The radar

The Ft Rucker radar (KEOX), 33 km from the middle of the area, began a volume at 20:00 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
50%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
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

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

IssuedProductOfficeCountiesLasted
Apr 22, 3:03 PM CDTTornado WarningBMXBarbour27 min
Apr 22, 3:21 PM CDTTornado WarningTAEWalton35 min
Apr 22, 3:22 PM CDTTornado WarningTAEHenry23 min
Apr 22, 3:23 PM CDTTornado WarningMOBOkaloosa16 min
Apr 22, 3:25 PM CDTTornado WarningBMXBarbour35 min
Apr 22, 3:36 PM CDTTornado WarningTAEDale, Henry, Houston24 min
Apr 22, 3:49 PM CDTSevere Thunderstorm WarningMOBEscambia, Santa Rosa41 min
Apr 22, 4:01 PM CDTTornado WarningMOBEscambia, Santa Rosa29 min
Apr 22, 4:08 PM CDTTornado WarningMOBOkaloosa37 min
Apr 22, 4:18 PM CDTTornado WarningTAEHenry27 min
Apr 22, 4:24 PM CDTSevere Thunderstorm WarningMOBSanta Rosa39 min
Apr 22, 4:31 PM CDTTornado Warning Tornado observedMOBOkaloosa15 min
Apr 22, 6:55 PM CDTTornado WarningTAEEarly, Miller35 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 12:00Z, 7.9 hours before the alert went out and 160 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 12:00Z on 2018-04-22Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tallahassee Rgnl, FL at 12:00Z on 2018-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 265 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
640 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
265 m²/s²
0-3 km storm-relative helicity
347 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

854 
WWUS20 KWNS 221951
SEL6  
SPC WW 221951
ALZ000-FLZ000-GAZ000-CWZ000-230200-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 56
NWS Storm Prediction Center Norman OK
255 PM CDT Sun Apr 22 2018

The NWS Storm Prediction Center has issued a

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

* Effective this Sunday afternoon and evening from 255 PM until
  900 PM CDT.

* Primary threats include...
  A few tornadoes possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Scattered showers and thunderstorms will overspread the
watch area this afternoon, with a few of the storms becoming severe
with isolated tornadoes and damaging wind gusts possible.

The tornado watch area is approximately along and 50 statute miles
east and west of a line from 50 miles northeast of Troy AL to 70
miles southwest of Panama City FL. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU6).

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 20035.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 22, 10:37 AM CDTMesoscale DiscussionSPCBaldwin, Choctaw, Clarke, Mobile, Washington2 hr
Apr 22, 1:58 PM CDTMesoscale DiscussionSPCBaldwin, Barbour, Butler, Coffee, Conecuh, Covington and 8 more3 hr
Apr 22, 3:58 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Chilton, Dallas, Fayette, Greene and 11 more3 hr

Nearby

Tornado Watches in Alabama, 2018Tornado Watches in Florida, 2018Tornado Watches in Georgia, 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.