Alert archive / North Carolina / Mesoscale Discussions in 2021

Mesoscale Discussion 283

March 27, 202125 counties in North Carolina; Halifax County, Mecklenburg County, Virginia

The Storm Prediction Center issued this mesoscale discussion at Mar 27, 2021, 4:49 PM EDT for 25 counties in North Carolina; Halifax County, Mecklenburg County, Virginia. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Mar 27, 2021, 4:49 PM EDT (20:49 UTC)
Expired
Mar 27, 2021, 5:45 PM EDT
In force
56 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 58
All 27 counties

Alamance County, NC, Caswell County, NC, Chatham County, NC, Durham County, NC, Edgecombe County, NC, Franklin County, NC, Granville County, NC, Greene County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Johnston County, NC, Lee County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Stanly County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Wilson County, NC, Halifax County, VA, Mecklenburg County, VA

The radar

The Raleigh/Durham radar (KRAX), 41 km from the middle of the area, began a volume at 20:53 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 8.8 hours before the alert went out and 128 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°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.

243 
ACUS11 KWNS 272049
SWOMCD
SPC MCD 272049 
NCZ000-VAZ000-272145-

Mesoscale Discussion 0283
NWS Storm Prediction Center Norman OK
0349 PM CDT Sat Mar 27 2021

Areas affected...Central/eastern North Carolina and southern
Virginia

Concerning...Severe Thunderstorm Watch 58...

Valid 272049Z - 272145Z

The severe weather threat for Severe Thunderstorm Watch 58
continues.

SUMMARY...Ongoing severe storms will continue to pose a risk for
severe winds and hail over the next couple of hours.

DISCUSSION...Recent radar imagery and storm reports show
strong/severe storms have continued to produce severe weather
throughout WW58 over the last few hours. A few storms (including a
supercell in Moore County, NC) have developed ahead of the main band
of convection indicating the environment remains unstable and
uninhibited. Additional storms may develop within the warm sector
over the next few hours with a risk for damaging wind gusts and
hail.

Farther north into southern Virginia, storms have generally
struggled due to a lack of buoyancy within the cooler and drier
airmass to the north of a quasi stationary front. Severe weather
will remain possible with the strongest cells mainly in the form of
marginally severe hail, though the greatest severe weather risk
across WW58 likely will remain cross North Carolina. A small
downstream watch may be necessary as storms approach the eastern
edge of the watch over the next 2 to 3 hours.

..Lyons.. 03/27/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...AKQ...MHX...RAH...RNK...GSP...

LAT...LON   36747815 36467757 36097740 35457740 35157779 35207801
            35318030 35898000 36597939 36787911 36747815

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, 2:03 PM EDTSevere Thunderstorm WatchSPCAlamance, Alexander, Alleghany, Burke, Cabarrus, Caldwell and 35 more6 hr
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

Mesoscale Discussions in North Carolina, 2021Mesoscale Discussions in Virginia, 2021Every mesoscale discussion 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.