Alert archive / Virginia / Mesoscale Discussions in 2019

Mesoscale Discussion 2131

October 31, 20195 states

The Storm Prediction Center issued this mesoscale discussion at Oct 31, 2019, 4:01 PM EDT for 5 states. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued
Oct 31, 2019, 4:01 PM EDT (20:01 UTC)
Expired
Oct 31, 2019, 6:00 PM EDT
In force
119 min
Issued by
the Storm Prediction Center
All 73 counties

Baltimore County, MD, Carroll County, MD, City of Baltimore, MD, Frederick County, MD, Howard County, MD, Montgomery County, MD, Washington County, MD, Caswell County, NC, Guilford County, NC, Rockingham County, NC, Adams County, PA, Cumberland County, PA, Franklin County, PA, Fulton County, PA, Lebanon County, PA, York County, PA, Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Augusta County, VA, Bedford County, VA, Buckingham County, VA, Campbell County, VA, Charlotte County, VA, City of Alexandria, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Danville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Martinsville, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Cumberland County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Franklin County, VA, Frederick County, VA, Goochland County, VA, Greene County, VA, Halifax County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Nelson 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, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Jefferson County, WV, Morgan County, WV

The radar

The Sterling radar (KLWX), 96 km from the middle of the area, began a volume at 20:04 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, 8.0 hours before the alert went out and 100 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, Washington/Dulle, VA at 12:00Z on 2019-10-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Washington/Dulle, VA at 12:00Z on 2019-10-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 280 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
489 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
280 m²/s²
0-3 km storm-relative helicity
246 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Oct 31, 11:12 AM EDTMesoscale DiscussionSPCGarrett2 hr
Oct 31, 1:11 PM EDTMesoscale DiscussionSPCAllegany, Frederick, Montgomery, Washington3 hr
Oct 31, 2:56 PM EDTTornado WatchSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 9 more10 hr
Oct 31, 7:14 PM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Calvert, Carroll, Cecil, Charles and 10 more2 hr
Oct 31, 7:56 PM EDTSevere Thunderstorm WatchSPCCaroline, Cecil, Kent, Queen Anne's, Talbot6 hr
Oct 31, 12:45 PM EDTTornado WatchSPCAlleghany, Ashe, Watauga4 hr
Oct 31, 3:16 PM EDTTornado WatchSPCCaswell, Northampton, Rockingham, Stokes, Surry, Wilkes and 1 more8 hr
Oct 31, 3:39 PM EDTTornado WatchSPCAlamance, Alexander, Anson, Burke, Cabarrus, Caldwell and 41 more7 hr
Oct 31, 6:36 PM EDTMesoscale DiscussionSPCAlamance, Anson, Caswell, Chatham, Cumberland, Durham and 26 more114 min
Oct 31, 4:46 PM EDTMesoscale DiscussionSPCBradford, Lackawanna, Pike, Susquehanna, Wayne119 min
Oct 31, 6:16 PM EDTSevere Thunderstorm WatchSPCBradford, Lackawanna, Luzerne, Pike, Susquehanna, Wayne and 1 more8 hr

Nearby

Mesoscale Discussions in Virginia, 2019Mesoscale Discussions in Maryland, 2019Mesoscale Discussions in Pennsylvania, 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.