Alert archive / Virginia / Mesoscale Discussions in 2017

Mesoscale Discussion 240

March 1, 20175 states

The Storm Prediction Center issued this mesoscale discussion at Mar 1, 2017, 9:44 AM EST for 5 states. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Mar 1, 2017, 9:44 AM EST (14:44 UTC)
Expired
Mar 1, 2017, 11:15 AM EST
In force
91 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 130 counties

Allegany County, MD, Baltimore County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Frederick County, MD, Garrett County, MD, Harford County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Washington County, MD, Alamance County, NC, Alleghany County, NC, Ashe County, NC, Caswell County, NC, Forsyth County, NC, Granville County, NC, Guilford County, NC, Orange County, NC, Person County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Vance County, NC, Yadkin County, NC, Adams County, PA, Bedford County, PA, Cumberland County, PA, Franklin County, PA, Fulton County, PA, Lancaster County, PA, Somerset County, PA, York County, PA, Albemarle County, VA, Alleghany County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Carroll County, VA, Charlotte County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Covington, VA, City of Danville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Galax, 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 Radford, VA, City of Richmond, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Craig County, VA, Culpeper County, VA, Cumberland County, VA, Fairfax County, VA, Fauquier County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Frederick County, VA, Giles County, VA, Goochland County, VA, Grayson County, VA, Greene County, VA, Halifax County, VA, Hanover County, VA, Henry County, VA, Highland County, VA, King George County, VA, Loudoun County, VA, Louisa County, VA, Lunenburg County, VA, Madison County, VA, Mecklenburg County, VA, Montgomery County, VA, Nelson County, VA, Nottoway County, VA, Orange County, VA, Page County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince William County, VA, Pulaski County, VA, Rappahannock County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Wythe County, VA, Berkeley County, WV, Grant County, WV, Greenbrier County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Monroe County, WV, Morgan County, WV, Pendleton County, WV, Pocahontas County, WV, Randolph County, WV, Tucker County, WV

The radar

The Sterling radar (KLWX), 132 km from the middle of the area, began a volume at 14:45 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, 2.7 hours before the alert went out and 134 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 2017-03-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 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 2017-03-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 361 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
8 J/kg
Mixed-layer CIN
-303 J/kg
Mixed-layer LCL
857 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
361 m²/s²
0-3 km storm-relative helicity
448 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
Mar 1, 10:38 AM ESTSevere Thunderstorm WatchSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more4 hr
Mar 1, 12:25 PM ESTMesoscale DiscussionSPCBaltimore, Carroll, Frederick, Howard, Montgomery, Washington and 1 more65 min
Mar 1, 12:50 PM ESTMesoscale DiscussionSPCCaroline, Dorchester, Saint Mary's, Somerset, Wicomico, Worcester55 min
Mar 1, 1:13 PM ESTSevere Thunderstorm WatchSPCCaroline, Cecil, Dorchester, Kent, Queen Anne's, Somerset and 3 more4 hr
Mar 1, 2:50 PM ESTMesoscale DiscussionSPCCaroline, Cecil, Dorchester, Queen Anne's, Somerset, Talbot and 2 more55 min
Mar 1, 12:48 PM ESTTornado WatchSPCCherokee, Clay6 hr
Mar 1, 2:07 PM ESTMesoscale DiscussionSPCAlexander, Buncombe, Burke, Cabarrus, Catawba, Cleveland and 16 more113 min
Mar 1, 3:02 PM ESTSevere Thunderstorm WatchSPCAlamance, Alexander, Anson, Avery, Buncombe, Burke and 43 more7 hr
Mar 1, 6:21 PM ESTMesoscale DiscussionSPCAlamance, Anson, Beaufort, Bertie, Bladen, Cabarrus and 40 more114 min
Mar 1, 2:19 AM ESTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Butler, Cambria, Clarion and 13 more86 min
Mar 1, 3:56 PM ESTMesoscale DiscussionSPCBeaver, Butler, Crawford, Lawrence, Mercer, Venango and 1 more2 hr
Mar 1, 6:28 AM ESTMesoscale DiscussionSPCDickenson, Lee, Wise2 hr
Mar 1, 7:47 AM ESTSevere Thunderstorm WatchSPCBuchanan, Dickenson, Lee, Russell, Scott, Washington and 3 more5 hr
Mar 1, 8:28 AM ESTMesoscale DiscussionSPCBuchanan, Dickenson, Lee, Russell, Scott, Tazewell and 2 more92 min
Mar 1, 2:32 AM ESTMesoscale DiscussionSPCBoone, Cabell, Calhoun, Clay, Fayette, Jackson and 12 more88 min
Mar 1, 6:48 AM ESTSevere Thunderstorm WatchSPCBarbour, Braxton, Cabell, Calhoun, Clay, Doddridge and 19 more5 hr

Nearby

Mesoscale Discussions in Virginia, 2017Mesoscale Discussions in North Carolina, 2017Mesoscale Discussions in West Virginia, 2017Every mesoscale discussion in 2017

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.