Alert archive / South Carolina / Tornado Watches in 2017

Tornado Watch 126

April 5, 20176 counties in North Carolina; 8 counties in South Carolina

The Storm Prediction Center issued this tornado watch at Apr 5, 2017, 2:45 PM EDT for 6 counties in North Carolina; 8 counties in South Carolina. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 5, 2017, 2:45 PM EDT (18:45 UTC)
Expired
Apr 5, 2017, 8:00 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Bladen County, NC, Brunswick County, NC, Columbus County, NC, New Hanover County, NC, Pender County, NC, Robeson County, NC, Darlington County, SC, Dillon County, SC, Florence County, SC, Georgetown County, SC, Horry County, SC, Marion County, SC, Marlboro County, SC, Williamsburg County, SC

The radar

The Wilmington radar (KLTX), 91 km from the middle of the area, began a volume at 18:44 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
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 5, 3:50 PM EDTSevere Thunderstorm WarningILMDarlington, Florence59 min
Apr 5, 5:02 PM EDTSevere Thunderstorm WarningILMBladen, Columbus, Robeson58 min
Apr 5, 5:11 PM EDTSevere Thunderstorm WarningILMGeorgetown, Williamsburg29 min
Apr 5, 5:24 PM EDTTornado WarningILMGeorgetown, Marion, Williamsburg51 min
Apr 5, 5:53 PM EDTTornado WarningILMHorry42 min
Apr 5, 5:59 PM EDTSevere Thunderstorm WarningILMBladen38 min
Apr 5, 7:08 PM EDTSevere Thunderstorm WarningILMBrunswick45 min
Apr 5, 7:29 PM EDTSevere Thunderstorm WarningILMBrunswick, New Hanover37 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

Charleston AFB, SC (KCHS), launched 12:00Z, 6.8 hours before the alert went out and 134 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, Charleston AFB, SC at 12:00Z on 2017-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 626 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, Charleston AFB, SC at 12:00Z on 2017-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.1939587897Sfc1 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
626 J/kg
Mixed-layer CIN
-105 J/kg
Mixed-layer LCL
862 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
178 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.2

Open this sounding in Storm Lab

The text

As transmitted.

824 
WWUS20 KWNS 051842
SEL6  
SPC WW 051842
NCZ000-SCZ000-060000-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 126
NWS Storm Prediction Center Norman OK
245 PM EDT Wed Apr 5 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southern North Carolina
  Southeast South Carolina

* Effective this Wednesday afternoon and evening from 245 PM
  until 800 PM EDT.

* Primary threats include...
  A couple tornadoes possible
  Isolated very large hail events to 2 inches in diameter possible
  Isolated damaging wind gusts to 70 mph possible

SUMMARY...Scattered severe thunderstorms will spread into coastal
South Carolina/southern North Carolina over the next few hours. 
Damaging winds and large hail are the primary threats but isolated
tornadoes are also possible.

The tornado watch area is approximately along and 50 statute miles
either side of a line from 35 miles southwest of Florence SC to 40
miles east northeast of Myrtle Beach SC. 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.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 125...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 26030.

...Darrow

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 5, 2:02 PM EDTMesoscale DiscussionSPCColumbus58 min
Apr 5, 4:23 PM EDTMesoscale DiscussionSPCBladen, Columbus97 min
Apr 5, 7:57 PM EDTMesoscale DiscussionSPCCherokee, Clay, Graham, Swain48 min
Apr 5, 10:25 AM EDTMesoscale DiscussionSPCAbbeville, Aiken, Allendale, Bamberg, Barnwell, Calhoun and 6 more95 min
Apr 5, 10:43 AM EDTMesoscale DiscussionSPCAiken, Allendale, Bamberg, Barnwell, Calhoun, Clarendon and 10 more2 hr
Apr 5, 11:38 AM EDTMesoscale DiscussionSPCAllendale, Hampton97 min
Apr 5, 12:54 PM EDTTornado Watch PDSSPCAiken, Allendale, Bamberg, Barnwell, Beaufort, Berkeley and 18 more10 hr
Apr 5, 3:12 PM EDTMesoscale DiscussionSPCAiken, Allendale, Barnwell, Edgefield, Lexington, McCormick and 2 more93 min
Apr 5, 6:29 PM EDTMesoscale DiscussionSPCBeaufort, Berkeley, Colleton, Georgetown, Jasper61 min

Nearby

Tornado Watches in South Carolina, 2017Tornado Watches in North Carolina, 2017Every tornado watch in 2017

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.