Alert archive / North Carolina / Tornado Watches in 2020

Tornado Watch 113

April 12, 20208 counties in North Carolina; 5 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Apr 12, 2020, 8:57 PM EDT for 8 counties in North Carolina; 5 counties in Tennessee. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 12, 2020, 8:57 PM EDT (00:57 UTC)
Expired
Apr 13, 2020, 3:00 AM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt

Counties Cherokee County, NC, Clay County, NC, Graham County, NC, Haywood County, NC, Jackson County, NC, Macon County, NC, Swain County, NC, Transylvania County, NC, Blount County, TN, Bradley County, TN, McMinn County, TN, Monroe County, TN, Polk County, TN

The radar

The Knoxville radar (KMRX), 92 km from the middle of the area, began a volume at 00:59 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
60%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 12, 9:37 PM EDTSevere Thunderstorm WarningMRXCherokee53 min
Apr 12, 9:59 PM EDTTornado WarningMRXPolk31 min
Apr 12, 10:28 PM EDTSevere Thunderstorm WarningMRXMonroe29 min
Apr 12, 11:16 PM EDTTornado Warning EmergencyMRXHamilton, Polk29 min
Apr 12, 11:28 PM EDTTornado Warning Tornado observedConsiderable damage threatMRXBradley, Polk32 min
Apr 12, 11:41 PM EDTSevere Thunderstorm WarningMRXBradley, Hamilton, McMinn, Meigs, Polk49 min
Apr 12, 11:56 PM EDTTornado WarningMRXBradley, McMinn, Polk34 min
Apr 13, 12:13 AM EDTSevere Thunderstorm WarningMRXCherokee, Clay62 min
Apr 13, 12:31 AM EDTSevere Thunderstorm WarningMRXBradley, Polk44 min
Apr 13, 12:59 AM EDTFlash Flood WarningMRXBradley, Hamilton, Polk3 hr
Apr 13, 1:00 AM EDTSevere Thunderstorm WarningMRXBlount24 min
Apr 13, 1:14 AM EDTFlash Flood WarningMRXBlount, Knox, Loudon, Monroe, Sevier3 hr
Apr 13, 1:28 AM EDTSevere Thunderstorm WarningMRXCherokee, Clay47 min
Apr 13, 1:29 AM EDTFlash Flood WarningGSPHaywood, Transylvania6 hr
Apr 13, 1:29 AM EDTFlash Flood WarningMRXCherokee, Clay3 hr
Apr 13, 1:36 AM EDTFlash Flood WarningMRXMcMinn, Monroe3 hr
Apr 13, 1:58 AM EDTFlash Flood WarningGSPJackson, Macon, Swain6 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 1.0 hours before the alert went out and 238 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, Peachtre/Fal Fld, GA at 00:00Z on 2020-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 404 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Peachtre/Fal Fld, GA at 00:00Z on 2020-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 733 square meters per square second.1939587897Sfc1 km3 km6 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
404 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
804 m above ground
0-6 km bulk shear
70 kt
0-1 km storm-relative helicity
733 m²/s²
0-3 km storm-relative helicity
874 m²/s²
Significant tornado parameter
1.3
Supercell composite
10.8

Open this sounding in Storm Lab

The text

As transmitted.

902 
WWUS20 KWNS 130054
SEL3  
SPC WW 130054
GAZ000-NCZ000-TNZ000-130600-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 113
NWS Storm Prediction Center Norman OK
855 PM EDT Sun Apr 12 2020

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Northeast Georgia
  Western North Carolina
  Southeast Tennessee

* Effective this Sunday night and Monday morning from 855 PM
  until 200 AM EDT.

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

SUMMARY...A small cluster of intense thunderstorms over north
Georgia continues to track northeastward into the watch area.  The
strongest cells will pose a risk of damaging wind gusts and isolated
tornadoes.

The tornado watch area is approximately along and 25 statute miles
north and south of a line from 130 miles west of Asheville NC to 5
miles south of Asheville NC. 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 106...WW 107...WW
108...WW 109...WW 110...WW 111...WW 112...

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 24035.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 8:41 PM EDTMesoscale DiscussionSPCCherokee, Clay, Graham, Jackson, Macon, Transylvania64 min
Apr 12, 11:17 PM EDTMesoscale DiscussionSPCAlexander, Anson, Avery, Buncombe, Burke, Cabarrus and 31 more88 min
Apr 13, 1:51 AM EDTTornado WatchSPCAlexander, Burke, Cabarrus, Caldwell, Catawba, Cleveland and 14 more6 hr
Apr 13, 2:39 AM EDTMesoscale DiscussionSPCAlamance, Anson, Cabarrus, Chatham, Cumberland, Davidson and 21 more96 min
Apr 13, 4:40 AM EDTMesoscale DiscussionSPCAlamance, Beaufort, Bertie, Bladen, Brunswick, Camden and 51 more95 min
Apr 13, 5:01 AM EDTTornado WatchSPCAlamance, Anson, Beaufort, Bertie, Bladen, Brunswick and 53 more7 hr
Apr 13, 6:46 AM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Chowan, Columbus, Craven and 32 more89 min
Apr 13, 9:56 AM EDTMesoscale DiscussionSPCCarteret, Dare, Hyde, Pamlico, Tyrrell, Washington64 min
Apr 12, 8:56 PM EDTMesoscale DiscussionSPCFayette, Lauderdale, Shelby, Tipton2 hr
Apr 12, 9:19 PM EDTSevere Thunderstorm WatchSPCBenton, Carroll, Chester, Crockett, Decatur, Dyer and 15 more4 hr
Apr 12, 10:44 PM EDTMesoscale DiscussionSPCCarroll, Chester, Crockett, Decatur, Dyer, Fayette and 10 more91 min
Apr 13, 12:19 AM EDTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Decatur, Dickson and 21 more86 min

Nearby

Tornado Watches in North Carolina, 2020Tornado Watches in Tennessee, 2020Every tornado watch in 2020

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.