Alert archive / North Carolina / Mesoscale Discussions in 2021

Mesoscale Discussion 1410

August 1, 202115 counties in North Carolina; 12 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Aug 1, 2021, 6:29 AM EDT for 15 counties in North Carolina; 12 counties in Virginia. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Aug 1, 2021, 6:29 AM EDT (10:29 UTC)
Expired
Aug 1, 2021, 8:00 AM EDT
In force
91 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 27 counties

Alamance County, NC, Caswell County, NC, Chatham County, NC, Davidson County, NC, Durham County, NC, Franklin County, NC, Granville County, NC, Guilford County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Rockingham County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Amelia County, VA, Appomattox County, VA, Brunswick County, VA, Campbell County, VA, Charlotte County, VA, City of Danville, VA, Halifax County, VA, Lunenburg County, VA, Mecklenburg County, VA, Nottoway County, VA, Pittsylvania County, VA, Prince Edward County, VA

The radar

The Raleigh/Durham radar (KRAX), 105 km from the middle of the area, began a volume at 10:30 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 10.5 hours before the alert went out and 77 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 00:00Z on 2021-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 36 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2021-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.193958Sfc1 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
36 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
1676 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

133 
ACUS11 KWNS 011029
SWOMCD
SPC MCD 011029 
VAZ000-NCZ000-011200-

Mesoscale Discussion 1410
NWS Storm Prediction Center Norman OK
0529 AM CDT Sun Aug 01 2021

Areas affected...portions of south-central VA and north-central NC

Concerning...Severe potential...Watch unlikely 

Valid 011029Z - 011200Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated small hail and gusty winds are possible with
stronger thunderstorms this morning. A watch is not expected at this
time.

DISCUSSION...Convection is increasing this morning in the vicinity
of a surface trough along the NC/VA Piedmont. Instability remains
modest across the region given poor midlevel lapse rates and time of
day. Furthermore, boundary-layer inhibition is likely resulting in
elevated convection. Nevertheless, effective-shear magnitudes around
30-40 kt have resulted in some semi-organized storm structures.
Vertically veering wind profiles and elongated hodographs suggests
some potential for briefly organized cells, but a lack of stronger
instability/lapse rates will limit overall severe potential over the
next few hours, with possibly some small hail and/or gusty winds
accompany the strongest cells.

..Leitman/Edwards.. 08/01/2021

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

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

LAT...LON   36198018 36967947 37297909 37397875 37457792 37207765
            36637786 35977836 35757866 35657943 35687996 35798031
            35938047 36198018

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 1, 10:54 AM EDTMesoscale DiscussionSPCBertie, Camden, Chowan, Currituck, Gates, Hertford and 4 more96 min
Aug 1, 11:51 AM EDTMesoscale DiscussionSPCBeaufort, Bertie, Chowan, Cumberland, Duplin, Edgecombe and 14 more114 min
Aug 1, 12:37 PM EDTSevere Thunderstorm WatchSPCBeaufort, Bladen, Brunswick, Carteret, Chatham, Columbus and 31 more7 hr
Aug 1, 2:53 PM EDTMesoscale DiscussionSPCAnson, Beaufort, Bertie, Bladen, Chatham, Columbus and 31 more97 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.