Alert archive / North Carolina / Mesoscale Discussions in 2021

Mesoscale Discussion 279

March 27, 202148 counties in North Carolina; Cherokee County, Spartanburg County, York County, South Carolina

The Storm Prediction Center issued this mesoscale discussion at Mar 27, 2021, 1:39 PM EDT for 48 counties in North Carolina; Cherokee County, Spartanburg County, York County, South Carolina. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
Mar 27, 2021, 1:39 PM EDT (17:39 UTC)
Expired
Mar 27, 2021, 2:45 PM EDT
In force
66 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
60%
All 51 counties

Alamance County, NC, Alexander County, NC, Anson County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Caswell County, NC, Catawba County, NC, Chatham County, NC, Cleveland County, NC, Cumberland County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Forsyth County, NC, Franklin County, NC, Gaston County, NC, Granville County, NC, Guilford County, NC, Harnett County, NC, Hoke County, NC, Iredell County, NC, Johnston County, NC, Lee County, NC, Lincoln County, NC, McDowell County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Polk County, NC, Randolph County, NC, Richmond County, NC, Rockingham County, NC, Rowan County, NC, Rutherford County, NC, Scotland County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Union County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wilkes County, NC, Yadkin County, NC, Cherokee County, SC, Spartanburg County, SC, York County, SC

The radar

The Raleigh/Durham radar (KRAX), 116 km from the middle of the area, began a volume at 17:39 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, 5.7 hours before the alert went out and 34 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.

351 
ACUS11 KWNS 271739
SWOMCD
SPC MCD 271739 
NCZ000-VAZ000-SCZ000-271845-

Mesoscale Discussion 0279
NWS Storm Prediction Center Norman OK
1239 PM CDT Sat Mar 27 2021

Areas affected...North/South Carolina into southern Virginia

Concerning...Severe potential...Watch possible 

Valid 271739Z - 271845Z

Probability of Watch Issuance...60 percent

SUMMARY...Thunderstorms across TN will move eastward into a
destabilizing environment this afternoon. A wind/hail risk will be
possible with storms through this evening. A watch is being
considered.

DISCUSSION...A band of thunderstorms associated with a mid-level
speed max were moving across the eastern Appalachians out of
Tennessee and north Carolina. 1700 UTC surface obs show temperatures
in the 70s south of warm front near the NC/VA border. Low-level
moisture advection is forecast to increase through the next few
hours as the front slowly moves north bringing mid to upper-60s
dewpoints across the Carolina Piedmont northwestward toward the
ongoing storms. Regional CAM soundings show 500-1500 J/kg of MUCAPE
and 45-50 kts of effective shear developing across much of North
Carolina this afternoon. Robust thunderstorms are expected to
persist with a threat for damaging wind gusts and severe hail into
this evening. A new weather watch may be needed.

..Lyons/Thompson.. 03/27/2021

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

ATTN...WFO...AKQ...RAH...ILM...RNK...CAE...GSP...

LAT...LON   36558078 36557953 36567863 36467823 36367800 36077791
            35667808 35107852 34777918 34688000 34738087 34948220
            35528220 36418159 36558078

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 27, 2:03 PM EDTSevere Thunderstorm WatchSPCAlamance, Alexander, Alleghany, Burke, Cabarrus, Caldwell and 35 more6 hr
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

Nearby

Mesoscale Discussions in North Carolina, 2021Mesoscale Discussions in South Carolina, 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.