Alert archive / South Carolina / Mesoscale Discussions in 2021
Mesoscale Discussion 313
The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2021, 6:24 PM EDT for 17 counties in Georgia; 4 counties in North Carolina; 20 counties in South Carolina. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 31, 2021, 6:24 PM EDT (22:24 UTC)
- Expired
- Mar 31, 2021, 8:30 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
All 41 counties
Bryan County, GA, Bulloch County, GA, Burke County, GA, Candler County, GA, Chatham County, GA, Effingham County, GA, Emanuel County, GA, Evans County, GA, Jenkins County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Richmond County, GA, Screven County, GA, Tattnall County, GA, Toombs County, GA, Wayne County, GA, Bladen County, NC, Brunswick County, NC, Columbus County, NC, Robeson County, NC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Berkeley County, SC, Calhoun County, SC, Charleston County, SC, Clarendon County, SC, Colleton County, SC, Dillon County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Marion County, SC, Orangeburg County, SC, Sumter County, SC, Williamsburg County, SC
The radar
The Charleston,SC radar (KCLX), 84 km from the middle of the area, began a volume at 22:24 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
Charleston AFB, SC (KCHS), launched 12:00Z, 10.4 hours before the alert went out and 43 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
- 717 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 567 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 57 m²/s²
- 0-3 km storm-relative helicity
- 122 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
592
ACUS11 KWNS 312224
SWOMCD
SPC MCD 312224
NCZ000-SCZ000-GAZ000-010030-
Mesoscale Discussion 0313
NWS Storm Prediction Center Norman OK
0524 PM CDT Wed Mar 31 2021
Areas affected...eastern South Carolina...southern North
Carolina...southeastern Georgia
Concerning...Severe potential...Watch unlikely
Valid 312224Z - 010030Z
Probability of Watch Issuance...20 percent
SUMMARY...Isolated severe hail or wind is possible for a few hours
centered over eastern South Carolina. A watch is not expected due to
storm coverage and duration.
DISCUSSION...Surface analysis and radar show outflow boundaries
progressing east/southeastward from eastern NC into central SC and
east-central GA. Cooler air with outflow-reinforced sea breeze is
also undercutting some of these storms. Scattered storms persist
ahead of these boundaries, with MLCAPE up to 1500 J/kg. Deep-layer
shear around 40 kt will likely support isolated strong or severe
cells into early evening while the air mass remains uncapped.
Effective SRH of 100-150 m2/s2 is a bit low for supercells, but may
support weak rotation in the near term before the air mass is
overturned and temperatures cool.
..Jewell/Edwards.. 03/31/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...RAH...ILM...CHS...CAE...JAX...FFC...
LAT...LON 33458207 33608131 34158026 34747925 34767869 34637830
34387815 34117813 33887830 33767865 33197910 32817956
32528001 32068070 31638102 31248120 31218163 31478208
32238253 32838252 33088237 33458207SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 31, 11:57 AM EDT | Mesoscale Discussion | SPC | Chattahoochee, Coweta, Fayette, Harris, Lamar, Marion and 9 more | 93 min |
| Mar 31, 3:52 PM EDT | Mesoscale Discussion | SPC | Baker, Calhoun, Clay, Crisp, Dooly, Dougherty and 10 more | 53 min |
| Mar 31, 4:12 PM EDT | Severe Thunderstorm Watch | SPC | Baker, Calhoun, Clay, Dougherty, Early, Lee and 4 more | 4 hr |
| Mar 31, 5:50 PM EDT | Mesoscale Discussion | SPC | Early, Miller, Seminole | 115 min |
| Mar 31, 2:22 PM EDT | Mesoscale Discussion | SPC | Alamance, Anson, Beaufort, Bertie, Bladen, Chatham and 43 more | 113 min |
Nearby
Mesoscale Discussions in South Carolina, 2021Mesoscale Discussions in Georgia, 2021Mesoscale Discussions in North 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.