Alert archive / North Carolina / Mesoscale Discussions in 2019
Mesoscale Discussion 1663
The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2019, 12:50 PM EDT for 4 states. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- Aug 7, 2019, 12:50 PM EDT (16:50 UTC)
- Expired
- Aug 7, 2019, 2:15 PM EDT
- In force
- 85 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 113 counties
Saint Mary's County, MD, Alamance County, NC, Anson County, NC, Beaufort County, NC, Bertie County, NC, Bladen 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, 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, Johnston County, NC, Jones County, NC, Lee County, NC, Lenoir County, NC, Martin 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, Person County, NC, Pitt County, NC, Randolph County, NC, Richmond County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Stanly County, NC, Tyrrell County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, Chesterfield County, SC, Marlboro County, SC, Amelia County, VA, Brunswick County, VA, Caroline County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield 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 Richmond, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Lunenburg County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Northumberland County, VA, Nottoway County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA
The radar
The Raleigh/Durham radar (KRAX), 82 km from the middle of the area, began a volume at 16:53 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, 4.8 hours before the alert went out and 166 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
- 2483 J/kg
- Mixed-layer CIN
- -4 J/kg
- Mixed-layer LCL
- 598 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 44 m²/s²
- 0-3 km storm-relative helicity
- 48 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 1.8
The text
As transmitted.
444
ACUS11 KWNS 071650
SWOMCD
SPC MCD 071650
VAZ000-NCZ000-MDZ000-SCZ000-071815-
Mesoscale Discussion 1663
NWS Storm Prediction Center Norman OK
1150 AM CDT Wed Aug 07 2019
Areas affected...Eastern North Carolina and eastern Virginia
Concerning...Severe potential...Watch likely
Valid 071650Z - 071815Z
Probability of Watch Issuance...80 percent
SUMMARY...Strong to severe storms are expected through the afternoon
and evening. A watch is possible.
DISCUSSION...Storms have started to form along a surface cold front
in central North Carolina. The airmass ahead of these storms is
already very unstable with surface dewpoints in the low to mid 70s
and temperatures approaching 90 yielding MLCAPE around 2000 to 2500
J/kg. Mid-level flow around 40 knots will provide sufficient shear
for storm organization. Expect one or more multicell clusters/line
segments to move across eastern North Carolina and southeast
Virginia through the afternoon and early evening. While mid-level
lapse rates are quite weak (~ 6 C/km), expect storms to have some
hail threat given the expected storm organization in a very unstable
environment. Low-level flow will be a limiting factor to wind
damage, but internal thermodynamic processes in the hot and unstable
airmass will support downdrafts that will be capable of damaging
winds.
..Bentley/Goss.. 08/07/2019
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...AKQ...MHX...LWX...RAH...ILM...RNK...CAE...GSP...
LAT...LON 35888010 36507916 37397858 38137770 38467684 38447634
38167605 37847591 36817599 36117557 35417547 35137588
34707676 34317760 34137797 34167840 34527986 34688033
35158039 35888010SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 7, 1:02 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 15 more | 88 min |
| Aug 7, 1:53 PM EDT | Severe Thunderstorm Watch | SPC | Anne Arundel, Baltimore, Calvert, Carroll, Charles, Dorchester and 10 more | 6 hr |
| Aug 7, 2:10 PM EDT | Severe Thunderstorm Watch | SPC | Caroline, Cecil, Kent, Queen Anne's, Talbot | 7 hr |
| Aug 7, 3:25 PM EDT | Mesoscale Discussion | SPC | Saint Mary's, Somerset | 65 min |
| Aug 7, 3:57 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Carroll, Cecil, Harford, Howard and 5 more | 93 min |
| Aug 7, 6:56 PM EDT | Mesoscale Discussion | SPC | Caroline, Queen Anne's, Talbot | 64 min |
| Aug 7, 7:15 PM EDT | Mesoscale Discussion | SPC | Beaufort, Camden, Chowan, Craven, Currituck, Dare and 7 more | 60 min |
Nearby
Mesoscale Discussions in North Carolina, 2019Mesoscale Discussions in Virginia, 2019Mesoscale Discussions in South Carolina, 2019Every mesoscale discussion in 2019
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.