Alert archive / South Carolina / Tornado Watches in 2018

Tornado Watch 52

April 15, 20184 states

The Storm Prediction Center issued this tornado watch at Apr 15, 2018, 12:13 PM EDT for 4 states. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Apr 15, 2018, 12:13 PM EDT (16:13 UTC)
Expired
Apr 15, 2018, 8:49 PM EDT
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 67 counties

Burke County, GA, Columbia County, GA, Lincoln County, GA, McDuffie County, GA, Richmond County, GA, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Catawba County, NC, Cleveland County, NC, Davie County, NC, Gaston County, NC, Iredell County, NC, Lincoln County, NC, McDowell County, NC, Mecklenburg County, NC, Polk County, NC, Rowan County, NC, Rutherford County, NC, Surry County, NC, Union County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Abbeville County, SC, Aiken County, SC, Allendale County, SC, Anderson County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Berkeley County, SC, Calhoun County, SC, Charleston County, SC, Cherokee County, SC, Chester County, SC, Chesterfield County, SC, Clarendon County, SC, Colleton County, SC, Dorchester County, SC, Edgefield County, SC, Fairfield County, SC, Greenville County, SC, Greenwood County, SC, Hampton County, SC, Jasper County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lee County, SC, Lexington County, SC, McCormick County, SC, Newberry County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Spartanburg County, SC, Sumter County, SC, Union County, SC, York County, SC, Carroll County, VA, City of Galax, VA, Floyd County, VA, Grayson County, VA

The radar

The Columbia radar (KCAE), 115 km from the middle of the area, began a volume at 16:16 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
70%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
70%
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
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 15, 12:13 PM EDTSevere Thunderstorm WarningGSPGreenwood, Laurens47 min
Apr 15, 12:19 PM EDTSevere Thunderstorm WarningGSPLaurens, Spartanburg41 min
Apr 15, 12:29 PM EDTSevere Thunderstorm WarningGSPCleveland, Rutherford46 min
Apr 15, 12:31 PM EDTFlash Flood WarningGSPCherokee, Greenwood, Laurens, Spartanburg3 hr
Apr 15, 12:38 PM EDTSevere Thunderstorm WarningGSPLaurens, Spartanburg, Union52 min
Apr 15, 12:41 PM EDTSevere Thunderstorm WarningCAEColumbia, Richmond34 min
Apr 15, 12:44 PM EDTFlash Flood WarningGSPBurke, Caldwell, Cleveland, Polk, Rutherford4 hr
Apr 15, 12:47 PM EDTSevere Thunderstorm WarningGSPBurke, Catawba, Cleveland, Lincoln, Rutherford28 min
Apr 15, 1:12 PM EDTSevere Thunderstorm WarningCAEBurke33 min
Apr 15, 1:13 PM EDTSevere Thunderstorm WarningGSPAlexander, Burke, Caldwell, Catawba, Cleveland, Lincoln32 min
Apr 15, 1:17 PM EDTSevere Thunderstorm WarningGSPCherokee, Spartanburg, Union43 min
Apr 15, 1:36 PM EDTSevere Thunderstorm WarningRNKAlleghany, Ashe, Surry, Wilkes69 min
Apr 15, 1:42 PM EDTSevere Thunderstorm WarningCAEAiken, Lexington, Newberry, Saluda48 min
Apr 15, 2:09 PM EDTTornado WarningCAELexington21 min
Apr 15, 2:12 PM EDTSevere Thunderstorm WarningRNKAlleghany, Surry, Wilkes, Yadkin63 min
Apr 15, 2:13 PM EDTSevere Thunderstorm WarningCAEAiken, Bamberg, Barnwell, Calhoun, Lexington, Orangeburg62 min
Apr 15, 2:18 PM EDTSevere Thunderstorm WarningCAECalhoun, Fairfield, Lexington, Newberry, Richland57 min
Apr 15, 2:29 PM EDTSevere Thunderstorm WarningGSPCherokee, Chester, Union, York46 min
Apr 15, 2:40 PM EDTSevere Thunderstorm WarningCAEFairfield, Kershaw, Lancaster, Richland65 min
Apr 15, 2:41 PM EDTSevere Thunderstorm WarningRNKBland, Carroll, Grayson, Pulaski, Wythe, City of Galax and 1 more64 min
Apr 15, 2:43 PM EDTTornado WarningCAEFairfield17 min
Apr 15, 2:44 PM EDTSevere Thunderstorm WarningGSPGaston, Mecklenburg46 min
Apr 15, 2:51 PM EDTTornado WarningCAEFairfield, Lancaster24 min
Apr 15, 3:01 PM EDTSevere Thunderstorm WarningCAEKershaw, Lancaster59 min
Apr 15, 3:02 PM EDTTornado WarningGSPGaston, Mecklenburg28 min
Apr 15, 3:03 PM EDTSevere Thunderstorm WarningRNKSurry, Wilkes, Yadkin42 min
Apr 15, 3:15 PM EDTSevere Thunderstorm WarningGSPMecklenburg, Union30 min
Apr 15, 3:25 PM EDTSevere Thunderstorm WarningGSPCabarrus, Catawba, Gaston, Iredell, Lincoln, Mecklenburg and 1 more37 min
Apr 15, 3:32 PM EDTSevere Thunderstorm WarningCAECalhoun, Clarendon, Kershaw, Lee, Orangeburg, Richland and 1 more58 min
Apr 15, 3:33 PM EDTSevere Thunderstorm WarningRNKStokes, Surry57 min
Apr 15, 3:41 PM EDTSevere Thunderstorm WarningGSPCabarrus, Mecklenburg, Rowan, Union34 min
Apr 15, 3:48 PM EDTSevere Thunderstorm WarningCAEChesterfield72 min
Apr 15, 3:55 PM EDTSevere Thunderstorm WarningGSPDavie, Iredell, Rowan35 min
Apr 15, 3:57 PM EDTSevere Thunderstorm WarningRNKBotetourt, Craig, Floyd, Franklin, Giles, Montgomery and 5 more63 min
Apr 15, 4:08 PM EDTSevere Thunderstorm WarningRNKRockingham, Stokes, Surry, Yadkin67 min
Apr 15, 4:14 PM EDTSevere Thunderstorm WarningGSPCabarrus, Rowan31 min
Apr 15, 5:12 PM EDTSevere Thunderstorm WarningRNKBedford, Botetourt, Floyd, Franklin, Henry, Patrick and 4 more63 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 4.2 hours before the alert went out and 154 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, Greensboro/Hi Pt, NC at 12:00Z on 2018-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 28 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, Greensboro/Hi Pt, NC at 12:00Z on 2018-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 104 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
28 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
638 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
104 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

979 
WWUS20 KWNS 151611
SEL2  
SPC WW 151611
GAZ000-NCZ000-SCZ000-VAZ000-CWZ000-152300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 52
NWS Storm Prediction Center Norman OK
1215 PM EDT Sun Apr 15 2018

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  East Georgia
  Western North Carolina
  South Carolina
  Far southern Virginia
  Coastal Waters

* Effective this Sunday afternoon and evening from 1215 PM until
  700 PM EDT.

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

SUMMARY...Bands of storms will continue to intensify and race
northeastward through the afternoon and early evening. A highly
sheared environment will support the possibility of line-embedded
circulations capable of tornadoes aside from wind damage, especially
with the more prominent bowing segments.

The tornado watch area is approximately along and 50 statute miles
east and west of a line from 75 miles north northeast of Hickory NC
to 75 miles south southeast of Augusta GA. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU2).

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 51...

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 21040.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 14, 11:58 PM EDTTornado WatchSPCClay, Early, Miller, Quitman, Randolph, Seminole8 hr
Apr 15, 2:45 AM EDTMesoscale DiscussionSPCCalhoun, Clay, Early, Miller, Quitman, Randolph and 1 more2 hr
Apr 15, 6:42 AM EDTMesoscale DiscussionSPCCalhoun, Clay, Early, Miller, Randolph, Seminole93 min
Apr 15, 9:34 AM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Ben Hill, Brantley, Camden and 17 more86 min
Apr 15, 10:12 AM EDTTornado WatchSPCAppling, Atkinson, Bacon, Brantley, Bryan, Bulloch and 29 more8 hr
Apr 15, 2:30 PM EDTMesoscale DiscussionSPCGlynn, McIntosh90 min
Apr 15, 11:15 AM EDTMesoscale DiscussionSPCAlexander, Anson, Cabarrus, Catawba, Davidson, Davie and 11 more2 hr
Apr 15, 2:29 PM EDTMesoscale DiscussionSPCAlamance, Anson, Caswell, Chatham, Cumberland, Davidson and 20 more91 min
Apr 15, 3:02 PM EDTTornado WatchSPCAlamance, Anson, Bladen, Brunswick, Caswell, Chatham and 34 more8 hr
Apr 15, 3:17 PM EDTMesoscale DiscussionSPCAnson, Cabarrus, Davidson, Davie, Forsyth, Rowan and 3 more88 min
Apr 15, 5:45 PM EDTMesoscale DiscussionSPCAlamance, Anson, Cabarrus, Caswell, Chatham, Cumberland and 24 more90 min
Apr 15, 6:28 PM EDTMesoscale DiscussionSPCCumberland, Franklin, Granville, Halifax, Johnston, Nash and 4 more62 min
Apr 15, 6:14 PM EDTTornado WatchSPCAmelia, Brunswick, Chesterfield, Cumberland, Dinwiddie, Fluvanna and 8 more7 hr

Nearby

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