Alert archive / North Carolina / Mesoscale Discussions in 2021

Mesoscale Discussion 1196

July 8, 202129 counties in North Carolina; 28 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 8, 2021, 12:11 PM EDT for 29 counties in North Carolina; 28 counties in Virginia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 8, 2021, 12:11 PM EDT (16:11 UTC)
Expired
Jul 8, 2021, 2:15 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Tornado watch 349
All 57 counties

Beaufort County, NC, Bertie County, NC, Camden County, NC, Carteret County, NC, Chowan County, NC, Craven County, NC, Currituck County, NC, Dare County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Greene County, NC, Halifax County, NC, Hertford County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Pamlico County, NC, Pasquotank County, NC, Perquimans County, NC, Pitt County, NC, Tyrrell County, NC, Vance County, NC, Warren County, NC, Washington County, NC, Wilson County, NC, Brunswick County, VA, Charles City County, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Dinwiddie County, VA, Gloucester County, VA, Greensville County, VA, Isle of Wight County, VA, James City County, VA, Lunenburg County, VA, Mecklenburg County, VA, Prince George County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 112 km from the middle of the area, began a volume at 16:12 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

Newport, NC (KMHX), launched 12:00Z, 4.2 hours before the alert went out and 133 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, Newport, NC at 12:00Z on 2021-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2167 joules per kilogram.LCLEL10008507005003002001001 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, Newport, NC at 12:00Z on 2021-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 70 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
2167 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
669 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
70 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.6

Open this sounding in Storm Lab

The text

As transmitted.

321 
ACUS11 KWNS 081612
SWOMCD
SPC MCD 081611 
NCZ000-VAZ000-081815-

Mesoscale Discussion 1196
NWS Storm Prediction Center Norman OK
1111 AM CDT Thu Jul 08 2021

Areas affected...northeast North Carolina into southeast Virginia

Concerning...Tornado Watch 349...

Valid 081611Z - 081815Z

The severe weather threat for Tornado Watch 349 continues.

SUMMARY...The threat for brief tornadoes continues in relation to
Elsa, and another watch may be needed extending downstream into
southeast Virginia.

DISCUSSION...Favorable instability is in place along and east of the
track of Elsa, with mid 70s F dewpoints contributing to around 1500
J/kg MLCAPE despite widespread rain and clouds. The stronger
low-level shear/effective SRH is in a relatively concentrated area
near the circulation, but this parameter space should bodily move
northeastward into VA today. Sporadic circulations have been noted
on radar with the primary zone of cells extending from Nash County
NC southeastward toward New Bern.  Cells farther away from the
center, currently over northeast NC and southeast VA, are in a
region of lesser shear, but this should gradually change over the
next several hours, necessitating a new watch.

..Jewell.. 07/08/2021

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

ATTN...WFO...AKQ...MHX...RAH...

LAT...LON   34517720 34947739 35287778 35617821 35777843 36177839
            36617850 36997833 37337754 37487688 37377618 37177577
            36777580 36297571 36007556 35777537 35237548 34947602
            34797634 34517720

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 8, 1:38 AM EDTMesoscale DiscussionSPCBladen, Brunswick, Columbus, New Hanover, Pender, Robeson2 hr
Jul 8, 2:01 AM EDTTornado WatchSPCBladen, Brunswick, Columbus, New Hanover, Pender7 hr
Jul 8, 7:09 AM EDTMesoscale DiscussionSPCBladen, Brunswick, Carteret, Columbus, Craven, Duplin and 11 more2 hr
Jul 8, 8:35 AM EDTTornado WatchSPCBeaufort, Bladen, Brunswick, Carteret, Columbus, Craven and 23 more6 hr
Jul 8, 1:50 PM EDTTornado WatchSPCBeaufort, Bertie, Camden, Chowan, Currituck, Dare and 11 more11 hr
Jul 8, 4:08 PM EDTMesoscale DiscussionSPCCamden, Chowan, Currituck, Gates, Hertford, Pasquotank and 2 more2 hr
Jul 8, 6:48 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Camden, Chowan, Currituck, Dare and 8 more117 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.