Alert archive / Virginia / Mesoscale Discussions in 2020

Mesoscale Discussion 312

April 8, 20204 states

The Storm Prediction Center issued this mesoscale discussion at Apr 8, 2020, 4:05 PM EDT for 4 states. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Apr 8, 2020, 4:05 PM EDT (20:05 UTC)
Expired
Apr 8, 2020, 5:30 PM EDT
In force
85 min
Issued by
the Storm Prediction Center
All 55 counties

Bath County, KY, Breathitt County, KY, Elliott County, KY, Floyd County, KY, Johnson County, KY, Knott County, KY, Lawrence County, KY, Magoffin County, KY, Martin County, KY, Menifee County, KY, Montgomery County, KY, Morgan County, KY, Pike County, KY, Powell County, KY, Rowan County, KY, Wolfe County, KY, Caswell County, NC, Person County, NC, Rockingham County, NC, Stokes County, NC, Bedford County, VA, Bland County, VA, Buchanan County, VA, Carroll County, VA, City of Danville, VA, City of Galax, VA, City of Martinsville, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Dickenson County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Halifax County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Roanoke County, VA, Smyth County, VA, Tazewell County, VA, Wythe County, VA, Boone County, WV, Logan County, WV, McDowell County, WV, Mercer County, WV, Mingo County, WV, Monroe County, WV, Raleigh County, WV, Summers County, WV, Wyoming County, WV

The radar

The Roanoke radar (KFCX), 81 km from the middle of the area, began a volume at 20:07 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

Roanoke, VA (KRNK), launched 12:00Z, 8.1 hours before the alert went out and 145 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, Roanoke, VA at 12:00Z on 2020-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 151 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, Roanoke, VA at 12:00Z on 2020-04-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 square meters per square second.1939587897117Sfc1 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
151 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
989 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
-20 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 8, 12:39 PM EDTMesoscale DiscussionSPCBath, Boyd, Bracken, Campbell, Carter, Elliott and 19 more96 min
Apr 8, 1:10 PM EDTSevere Thunderstorm WatchSPCBath, Bourbon, Boyd, Bracken, Carter, Elliott and 21 more7 hr
Apr 8, 4:45 PM EDTMesoscale DiscussionSPCBallard, Carlisle, McCracken2 hr
Apr 8, 5:24 PM EDTTornado WatchSPCBallard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 16 more7 hr
Apr 8, 6:52 PM EDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Boone and 65 more2 hr
Apr 8, 7:24 PM EDTTornado WatchSPCAdair, Allen, Anderson, Barren, Boone, Bourbon and 55 more5 hr
Apr 8, 6:06 PM EDTMesoscale DiscussionSPCAlamance, Caswell, Chatham, Davidson, Durham, Edgecombe and 23 more84 min
Apr 8, 1:52 AM EDTMesoscale DiscussionSPCFrederick, City of Winchester83 min
Apr 8, 2:14 AM EDTSevere Thunderstorm WatchSPCFrederick, City of Winchester2 hr
Apr 8, 3:53 AM EDTMesoscale DiscussionSPCArlington, Clarke, Fairfax, Fauquier, Frederick, Loudoun and 11 more97 min
Apr 8, 5:30 AM EDTMesoscale DiscussionSPCBath, Highland30 min
Apr 7, 10:04 PM EDTMesoscale DiscussionSPCHancock86 min
Apr 7, 11:40 PM EDTSevere Thunderstorm WatchSPCBarbour, Braxton, Brooke, Calhoun, Doddridge, Gilmer and 22 more6 hr
Apr 8, 3:16 AM EDTMesoscale DiscussionSPCBarbour, Braxton, Calhoun, Doddridge, Gilmer, Harrison and 13 more89 min

Nearby

Mesoscale Discussions in Virginia, 2020Mesoscale Discussions in Kentucky, 2020Mesoscale Discussions in West Virginia, 2020Every mesoscale discussion in 2020

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.