Alert archive / North Carolina / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 58

March 27, 202141 counties in North Carolina; 9 counties in Virginia

The Storm Prediction Center issued this severe thunderstorm watch at Mar 27, 2021, 2:03 PM EDT for 41 counties in North Carolina; 9 counties in Virginia. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Mar 27, 2021, 2:03 PM EDT (18:03 UTC)
Expired
Mar 27, 2021, 8:00 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 50 counties

Alamance County, NC, Alexander County, NC, Alleghany County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Caswell County, NC, Catawba County, NC, Chatham County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Iredell County, NC, Johnston County, NC, Lee County, NC, Lincoln County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Rockingham County, NC, Rowan County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Wilkes County, NC, Wilson County, NC, Yadkin County, NC, Carroll County, VA, City of Danville, VA, City of Martinsville, VA, Floyd County, VA, Franklin County, VA, Halifax County, VA, Henry County, VA, Patrick County, VA, Pittsylvania County, VA

The radar

The Roanoke radar (KFCX), 102 km from the middle of the area, began a volume at 18:04 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 27, 2:04 PM EDTSevere Thunderstorm WarningRNKFloyd, Franklin, Patrick41 min
Mar 27, 2:06 PM EDTSevere Thunderstorm WarningRNKAlleghany, Ashe, Surry, Watauga, Wilkes39 min
Mar 27, 2:19 PM EDTSevere Thunderstorm WarningGSPAlexander, Caldwell29 min
Mar 27, 2:31 PM EDTSevere Thunderstorm WarningRAHDavidson, Guilford, Randolph59 min
Mar 27, 2:38 PM EDTSevere Thunderstorm WarningRNKBedford, Campbell, Franklin, Pittsylvania52 min
Mar 27, 2:56 PM EDTSevere Thunderstorm WarningRNKRockingham, Stokes, Surry, Wilkes, Yadkin64 min
Mar 27, 3:17 PM EDTSevere Thunderstorm WarningRAHAlamance, Guilford, Orange, Randolph43 min
Mar 27, 3:59 PM EDTSevere Thunderstorm WarningGSPCabarrus, Mecklenburg31 min
Mar 27, 4:12 PM EDTSevere Thunderstorm WarningRAHChatham, Montgomery, Moore, Randolph48 min
Mar 27, 4:17 PM EDTSevere Thunderstorm WarningGSPCabarrus, Rowan28 min
Mar 27, 4:19 PM EDTTornado WarningRAHLee, Montgomery, Moore41 min
Mar 27, 4:26 PM EDTSevere Thunderstorm WarningRAHAlamance, Chatham, Davidson, Randolph64 min
Mar 27, 4:29 PM EDTSevere Thunderstorm WarningRAHMontgomery, Stanly46 min
Mar 27, 4:42 PM EDTSevere Thunderstorm WarningRAHChatham, Durham, Franklin, Granville, Wake48 min
Mar 27, 4:57 PM EDTSevere Thunderstorm WarningRAHHarnett, Lee, Moore48 min
Mar 27, 5:07 PM EDTSevere Thunderstorm WarningRAHAnson, Montgomery, Moore, Richmond, Stanly38 min
Mar 27, 5:13 PM EDTTornado WarningRAHJohnston, Nash, Wake, Wilson47 min
Mar 27, 5:42 PM EDTSevere Thunderstorm WarningRAHCumberland, Harnett, Johnston, Lee, Moore, Sampson and 1 more48 min
Mar 27, 6:00 PM EDTSevere Thunderstorm WarningRAHEdgecombe, Nash, Wilson45 min
Mar 27, 6:24 PM EDTSevere Thunderstorm WarningRAHJohnston, Wayne, Wilson51 min
Mar 27, 6:36 PM EDTTornado WarningRAHJohnston, Wayne54 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, 6.1 hours before the alert went out and 14 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 2021-03-27Temperature 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, Greensboro/Hi Pt, NC at 12:00Z on 2021-03-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2434 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

616 
WWUS20 KWNS 271800
SEL8  
SPC WW 271800
NCZ000-VAZ000-280000-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 58
NWS Storm Prediction Center Norman OK
200 PM EDT Sat Mar 27 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Parts of northern and central North Carolina
  Parts of extreme southern Virginia

* Effective this Saturday afternoon and evening from 200 PM until
  800 PM EDT.

* Primary threats include...
  Scattered damaging wind gusts to 70 mph possible
  Isolated large hail events to 1.5 inches in diameter possible

SUMMARY...A cluster of storms crossing the Appalachians will likely
maintain organization while it moves eastward near and just south of
the Virginia/North Carolina border.  The storm environment favors a
threat of damaging winds and large hail through the afternoon and
into this evening.

The severe thunderstorm watch area is approximately along and 45
statute miles north and south of a line from 80 miles west of
Greensboro NC to 40 miles east of Raleigh NC. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for 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. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
27030.

...Thompson

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 27, 1:39 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Anson, Burke, Cabarrus, Caldwell and 42 more66 min
Mar 27, 4:49 PM EDTMesoscale DiscussionSPCAlamance, Caswell, Chatham, Durham, Edgecombe, Franklin and 19 more56 min
Mar 27, 5:29 PM EDTSevere Thunderstorm WatchSPCAnson, Beaufort, Craven, Cumberland, Duplin, Greene and 13 more5 hr
Mar 27, 7:53 PM EDTMesoscale DiscussionSPCBeaufort, Carteret, Craven, Duplin, Greene, Hyde and 7 more97 min
Mar 27, 11:00 AM EDTMesoscale DiscussionSPCLee, Scott, City of Bristol, City of Norton90 min

Nearby

Severe Thunderstorm Watches in North Carolina, 2021Severe Thunderstorm Watches in Virginia, 2021Every severe thunderstorm watch in 2021

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.