Alert archive / Georgia / Tornado Watches in 2018

Tornado Watch 437

December 2, 201844 counties in Georgia; Beaufort County, Jasper County, South Carolina

The Storm Prediction Center issued this tornado watch at Dec 2, 2018, 10:00 AM EST for 44 counties in Georgia; Beaufort County, Jasper County, South Carolina. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Dec 2, 2018, 10:00 AM EST (15:00 UTC)
Expired
Dec 2, 2018, 6:00 PM EST
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 46 counties

Appling County, GA, Atkinson County, GA, Bacon County, GA, Ben Hill County, GA, Berrien County, GA, Brantley County, GA, Brooks County, GA, Bryan County, GA, Bulloch County, GA, Camden County, GA, Candler County, GA, Charlton County, GA, Chatham County, GA, Clinch County, GA, Coffee County, GA, Colquitt County, GA, Cook County, GA, Decatur County, GA, Echols County, GA, Effingham County, GA, Evans County, GA, Glynn County, GA, Grady County, GA, Irwin County, GA, Jeff Davis County, GA, Lanier County, GA, Liberty County, GA, Long County, GA, Lowndes County, GA, McIntosh County, GA, Mitchell County, GA, Montgomery County, GA, Pierce County, GA, Seminole County, GA, Tattnall County, GA, Telfair County, GA, Thomas County, GA, Tift County, GA, Toombs County, GA, Turner County, GA, Ware County, GA, Wayne County, GA, Wheeler County, GA, Worth County, GA, Beaufort County, SC, Jasper County, SC

The radar

The Moody AFB radar (KVAX), 73 km from the middle of the area, began a volume at 15:00 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
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Dec 2, 10:07 AM ESTSevere Thunderstorm WarningTAEBrooks, Lowndes, Thomas23 min
Dec 2, 1:48 PM ESTTornado WarningJAXClinch, Ware27 min
Dec 2, 2:06 PM ESTSevere Thunderstorm WarningJAXAtkinson28 min
Dec 2, 2:13 PM ESTTornado WarningJAXAtkinson19 min
Dec 2, 2:31 PM ESTSevere Thunderstorm WarningJAXAtkinson, Coffee18 min
Dec 2, 2:36 PM ESTSevere Thunderstorm WarningJAXCamden, Glynn39 min
Dec 2, 2:37 PM ESTSevere Thunderstorm WarningJAXCamden23 min
Dec 2, 2:41 PM ESTTornado WarningJAXCamden34 min
Dec 2, 2:44 PM ESTSevere Thunderstorm WarningJAXAtkinson, Coffee, Ware16 min
Dec 2, 3:00 PM ESTTornado WarningJAXCamden30 min
Dec 2, 3:20 PM ESTSevere Thunderstorm WarningJAXCamden40 min
Dec 2, 3:34 PM ESTTornado WarningJAXCamden26 min
Dec 2, 3:59 PM ESTSevere Thunderstorm WarningJAXCamden, Glynn46 min
Dec 2, 4:26 PM ESTSevere Thunderstorm WarningJAXCamden34 min
Dec 2, 4:27 PM ESTSevere Thunderstorm WarningTAEBrooks, Lowndes33 min
Dec 2, 5:38 PM ESTSevere Thunderstorm WarningJAXBrantley, Charlton, Ware37 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

Jacksonville, FL (KJAX), launched 12:00Z, 3.0 hours before the alert went out and 163 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, Jacksonville, FL at 12:00Z on 2018-12-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1274 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, Jacksonville, FL at 12:00Z on 2018-12-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 294 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
1274 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
520 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
294 m²/s²
0-3 km storm-relative helicity
302 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.9

Open this sounding in Storm Lab

The text

As transmitted.

910 
WWUS20 KWNS 021458
SEL7  
SPC WW 021458
GAZ000-SCZ000-CWZ000-022300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 437
NWS Storm Prediction Center Norman OK
1000 AM EST Sun Dec 2 2018

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southern Georgia
  Southern South Carolina
  Coastal Waters

* Effective this Sunday morning and evening from 1000 AM until
  600 PM EST.

* Primary threats include...
  A couple tornadoes possible
  Scattered damaging wind gusts to 70 mph possible
  Isolated large hail events to 1 inch in diameter possible

SUMMARY...Scattered strong to severe thunderstorms will spread
east-northeastward across the watch area through the day.  The
strongest cells will have a risk of damaging wind gusts and perhaps
a few tornadoes.

The tornado watch area is approximately along and 45 statute miles
north and south of a line from 40 miles north northwest of
Tallahassee FL to 50 miles east of Savannah GA. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU7).

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 436...

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 500. Mean
storm motion vector 25035.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 1, 10:18 PM ESTMesoscale DiscussionSPCCalhoun, Gadsden, Holmes, Jackson, Jefferson, Leon and 5 more87 min
Dec 2, 12:27 AM ESTMesoscale DiscussionSPCHolmes93 min
Dec 2, 3:03 AM ESTMesoscale DiscussionSPCGadsden, Holmes, Jackson, Leon, Washington2 hr
Dec 2, 7:00 AM ESTMesoscale DiscussionSPCJackson2 hr
Dec 2, 12:32 PM ESTMesoscale DiscussionSPCLeon88 min
Dec 2, 3:48 AM ESTTornado WatchSPCBaker, Ben Hill, Berrien, Brooks, Calhoun, Clay and 32 more7 hr

Nearby

Tornado Watches in Georgia, 2018Tornado Watches in South Carolina, 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.