Alert archive / Virginia / Mesoscale Discussions in 2018
Mesoscale Discussion 1722
The Storm Prediction Center issued this mesoscale discussion at Dec 21, 2018, 2:33 PM EST for 4 states. It was in force for 57 min.
The area
The outline as issued.
The facts
- Issued
- Dec 21, 2018, 2:33 PM EST (19:33 UTC)
- Expired
- Dec 21, 2018, 3:30 PM EST
- In force
- 57 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
All 89 counties
Alamance County, NC, Bladen County, NC, Caswell County, NC, Chatham County, NC, Columbus County, NC, Cumberland County, NC, Duplin County, NC, Durham County, NC, Edgecombe County, NC, Franklin County, NC, Granville County, NC, Greene County, NC, Halifax County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Lee County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Wilson County, NC, Dillon County, SC, Marion County, SC, Marlboro County, SC, Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Charlotte County, VA, Chesterfield County, VA, City of Charlottesville, VA, City of Colonial Heights, VA, City of Danville, VA, City of Emporia, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Petersburg, VA, City of Richmond, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Cumberland County, VA, Dinwiddie County, VA, Fauquier County, VA, Fluvanna County, VA, Frederick County, VA, Goochland County, VA, Greene County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Loudoun County, VA, Louisa County, VA, Lunenburg County, VA, Madison County, VA, Mecklenburg County, VA, Nelson County, VA, Nottoway County, VA, Orange County, VA, Page County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Hardy County, WV, Jefferson County, WV
The radar
The Raleigh/Durham radar (KRAX), 140 km from the middle of the area, began a volume at 19:34 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
Washington/Dulle, VA (KIAD), launched 12:00Z, 7.6 hours before the alert went out and 250 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
- 91 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 533 m above ground
- 0-6 km bulk shear
- 93 kt
- 0-1 km storm-relative helicity
- 224 m²/s²
- 0-3 km storm-relative helicity
- 139 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.0
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 20, 8:59 PM EST | Mesoscale Discussion | SPC | Beaufort, Carteret, Craven, Dare, Hyde, Jones and 2 more | 2 hr |
| Dec 21, 4:16 PM EST | Mesoscale Discussion | SPC | Arlington, Fairfax, Loudoun, City of Alexandria, City of Fairfax, City of Falls Church | 59 min |
Nearby
Mesoscale Discussions in Virginia, 2018Mesoscale Discussions in North Carolina, 2018Mesoscale Discussions in South Carolina, 2018Every mesoscale discussion in 2018
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.