Alert archive / North Carolina / Mesoscale Discussions in 2021
Mesoscale Discussion 800
The Storm Prediction Center issued this mesoscale discussion at May 29, 2021, 12:37 PM EDT for 65 counties in North Carolina; 15 counties in South Carolina; 10 counties in Virginia. It was in force for 113 min.
The area
The outline as issued.
The facts
- Issued
- May 29, 2021, 12:37 PM EDT (16:37 UTC)
- Expired
- May 29, 2021, 2:30 PM EDT
- In force
- 113 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
All 90 counties
Alamance County, NC, Anson County, NC, Beaufort County, NC, Bertie County, NC, Bladen County, NC, Brunswick County, NC, Cabarrus County, NC, Camden County, NC, Carteret County, NC, Chatham County, NC, Chowan County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Currituck County, NC, Dare County, NC, Davidson County, NC, Davie County, NC, Duplin County, NC, Durham County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Greene County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Hoke County, NC, Hyde County, NC, Iredell County, NC, Johnston County, NC, Jones County, NC, Lee County, NC, Lenoir County, NC, Martin County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, New Hanover County, NC, Northampton County, NC, Onslow County, NC, Orange County, NC, Pamlico County, NC, Pasquotank County, NC, Pender County, NC, Perquimans County, NC, Pitt County, NC, Randolph County, NC, Richmond County, NC, Robeson County, NC, Rowan County, NC, Sampson County, NC, Scotland County, NC, Stanly County, NC, Tyrrell County, NC, Union County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, Berkeley County, SC, Chesterfield County, SC, Clarendon County, SC, Darlington County, SC, Dillon County, SC, Florence County, SC, Georgetown County, SC, Horry County, SC, Kershaw County, SC, Lancaster County, SC, Lee County, SC, Marion County, SC, Marlboro County, SC, Sumter County, SC, Williamsburg County, SC, City of Chesapeake, VA, City of Emporia, VA, City of Franklin, VA, City of Norfolk, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, Greensville County, VA, Isle of Wight County, VA, Southampton County, VA
The radar
The Raleigh/Durham radar (KRAX), 49 km from the middle of the area, began a volume at 16:41 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 nearest sounding before it
Newport, NC (KMHX), launched 12:00Z, 4.6 hours before the alert went out and 131 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.
- Mixed-layer CAPE
- 873 J/kg
- Mixed-layer CIN
- -49 J/kg
- Mixed-layer LCL
- 888 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 124 m²/s²
- 0-3 km storm-relative helicity
- 132 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.8
The text
As transmitted.
223
ACUS11 KWNS 291637
SWOMCD
SPC MCD 291637
NCZ000-VAZ000-SCZ000-291830-
Mesoscale Discussion 0800
NWS Storm Prediction Center Norman OK
1137 AM CDT Sat May 29 2021
Areas affected...Southeast VA...much of central/eastern NC...and
portions of eastern SC
Concerning...Severe potential...Watch unlikely
Valid 291637Z - 291830Z
Probability of Watch Issuance...20 percent
SUMMARY...Thunderstorms are expected to increase in coverage this
afternoon with a risk for strong/possibly severe wind gusts. The
overall severe risk should remain isolated and thus a watch is not
currently anticipated.
DISCUSSION...A cold front extends from the lower Delmarva peninsula
southwest to western SC at 16z. South of this front, temperatures
have warmed into the 80s, combining with mostly upper 60s surface
dew points to result in MLCAPE generally in the 1000-1500 J/kg
range. Thunderstorms have developed within a confluence zone across
eastern NC, and additional thunderstorm development is expected
along and in advance of the front as heating combines with frontal
convergence this afternoon, further reducing remaining CINH.
Southwesterly mid-level flow averages 25-35 kts, and this should
contribute to organized multicell storms and perhaps transient
supercell structures. Strong/damaging wind gusts will be the main
severe weather risk with storms.
Overall, the risk for damaging wind gusts should remain isolated,
and as a result a watch is not expected.
..Bunting/Hart.. 05/29/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...AKQ...MHX...RAH...ILM...RNK...CHS...CAE...GSP...
LAT...LON 32897989 34248069 35018108 35798091 36018066 36237971
36457815 36997688 37047617 36707577 35897543 35507541
35287542 35067572 33107876 32897989Nearby
Mesoscale Discussions in North Carolina, 2021Mesoscale Discussions in South 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.