Alert archive / Georgia / Tornado Watches in 2018

Tornado Watch 425

November 6, 201818 counties in Georgia; 5 counties in North Carolina; 14 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Nov 6, 2018, 3:15 AM EST for 18 counties in Georgia; 5 counties in North Carolina; 14 counties in Tennessee. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Nov 6, 2018, 3:15 AM EST (08:15 UTC)
Expired
Nov 6, 2018, 8:02 AM EST
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
65 kt
All 37 counties

Catoosa County, GA, Chattooga County, GA, Dade County, GA, Dawson County, GA, Fannin County, GA, Floyd County, GA, Gilmer County, GA, Gordon County, GA, Habersham County, GA, Lumpkin County, GA, Murray County, GA, Pickens County, GA, Rabun County, GA, Towns County, GA, Union County, GA, Walker County, GA, White County, GA, Whitfield County, GA, Cherokee County, NC, Clay County, NC, Graham County, NC, Macon County, NC, Swain County, NC, Anderson County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Knox County, TN, Loudon County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Roane County, TN, Scott County, TN, Sevier County, TN

The radar

The Knoxville radar (KMRX), 80 km from the middle of the area, began a volume at 08:14 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
50%
One or more gusts of 65 knots or more
30%
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
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Nov 6, 3:43 AM ESTSevere Thunderstorm WarningMRXLoudon, McMinn, Meigs, Monroe, Rhea, Roane47 min
Nov 6, 3:58 AM ESTSevere Thunderstorm WarningFFCCatoosa, Chattooga, Dade, Walker, Whitfield62 min
Nov 6, 4:00 AM ESTSevere Thunderstorm WarningMRXBradley, Hamilton45 min
Nov 6, 4:16 AM ESTSevere Thunderstorm WarningMRXAnderson, Blount, Knox, Loudon, Monroe, Roane44 min
Nov 6, 4:39 AM ESTTornado WarningMRXBradley, McMinn, Polk36 min
Nov 6, 4:44 AM ESTSevere Thunderstorm WarningMRXBradley, McMinn, Monroe, Polk61 min
Nov 6, 4:49 AM ESTSevere Thunderstorm WarningMRXClaiborne, Grainger, Knox, Union41 min
Nov 6, 4:52 AM ESTSevere Thunderstorm WarningFFCFannin, Gilmer, Murray, Walker, Whitfield38 min
Nov 6, 4:52 AM ESTSevere Thunderstorm WarningMRXBlount, Hamblen, Jefferson, Knox, Sevier38 min
Nov 6, 4:57 AM ESTTornado WarningMRXMcMinn, Monroe30 min
Nov 6, 5:14 AM ESTSevere Thunderstorm WarningMRXCherokee, Clay61 min
Nov 6, 5:21 AM ESTSevere Thunderstorm WarningFFCFannin, Gilmer, Gordon, Murray, Pickens38 min
Nov 6, 5:21 AM ESTSevere Thunderstorm WarningMRXCocke, Greene, Hamblen, Jefferson, Sevier39 min
Nov 6, 5:26 AM ESTSevere Thunderstorm WarningGSPGraham, Swain49 min
Nov 6, 7:04 AM ESTSevere Thunderstorm WarningFFCCherokee, Dawson, Forsyth, Hall15 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

Nashville Metro, TN (KBNA), launched 00:00Z, 8.3 hours before the alert went out and 247 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, Nashville Metro, TN at 00:00Z on 2018-11-06Temperature 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, Nashville Metro, TN at 00:00Z on 2018-11-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 521 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
711 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
521 m²/s²
0-3 km storm-relative helicity
667 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

644 
WWUS20 KWNS 060812
SEL5  
SPC WW 060812
GAZ000-NCZ000-TNZ000-061400-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 425
NWS Storm Prediction Center Norman OK
415 AM EDT Tue Nov 6 2018

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Northern Georgia
  Western North Carolina
  Eastern Tennessee

* Effective this Tuesday morning from 415 AM until 1000 AM EDT.

* Primary threats include...
  A couple tornadoes possible
  Scattered damaging winds and isolated significant gusts to 75
    mph possible

SUMMARY...Fast-moving storms will cross the region through the early
morning hours. While instability will be minimal, continued
low-level moistening and very strong low/mid-level winds will
support fast-moving bowing segments and embedded meso-vortices
capable of wind damage and some tornado risk.

The tornado watch area is approximately along and 50 statute miles
east and west of a line from 50 miles north northeast of Knoxville
TN to 55 miles south southeast of Chattanooga TN. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU5).

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 423...WW 424...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 0.5 inches. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 24045.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 6, 2:40 AM ESTMesoscale DiscussionSPCBartow, Catoosa, Chattooga, Dade, Dawson, Fannin and 13 more65 min
Nov 5, 8:04 PM ESTTornado WatchSPCBedford, Benton, Cannon, Carroll, Cheatham, Chester and 37 more8 hr
Nov 5, 10:28 PM ESTMesoscale DiscussionSPCChester, Decatur, Dickson, Hardeman, Hardin, Henderson and 9 more2 hr
Nov 5, 11:30 PM ESTTornado WatchSPCBledsoe, Clay, Cumberland, DeKalb, Fentress, Franklin and 14 more7 hr

Nearby

Tornado Watches in Georgia, 2018Tornado Watches in Tennessee, 2018Tornado Watches in North 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.