Alert archive / Virginia / Mesoscale Discussions in 2017

Mesoscale Discussion 246

March 1, 20176 states

The Storm Prediction Center issued this mesoscale discussion at Mar 1, 2017, 2:50 PM EST for 6 states. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: Mar 1, 2017, 2:50 PM EST (19:50 UTC)
Expired: Mar 1, 2017, 3:45 PM EST
In force: 55 min
Issued by: the Storm Prediction Center

All 57 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Cecil County, MD, Dorchester County, MD, Queen Anne's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Salem County, NJ, Somerset County, NJ, Union County, NJ, Warren County, NJ, Richmond County, NY, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA, Accomack County, VA, Charles City County, VA, Chesterfield County, VA, City of Colonial Heights, VA, City of Hopewell, VA, City of Petersburg, VA, City of Williamsburg, VA, Gloucester County, VA, Henrico County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Prince George County, VA, Richmond County, VA, Surry County, VA, York County, VA

The radar

The Dover AFB radar (KDOX), 25 km from the middle of the area, began a volume at 19:49 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 7.8 hours before the alert went out and 87 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 127 J/kg
Mixed-layer CIN: -119 J/kg
Mixed-layer LCL: 840 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: 287 m²/s²
0-3 km storm-relative helicity: 274 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

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.

Issued	Product	Office	Counties	Lasted
Mar 1, 12:50 PM EST	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	55 min
Mar 1, 1:13 PM EST	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	4 hr
Mar 1, 9:44 AM EST	Mesoscale Discussion	SPC	Allegany, Baltimore, Carroll, Charles, Frederick, Garrett and 6 more	91 min
Mar 1, 10:38 AM EST	Severe Thunderstorm Watch	SPC	Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more	4 hr
Mar 1, 12:25 PM EST	Mesoscale Discussion	SPC	Baltimore, Carroll, Frederick, Howard, Montgomery, Washington and 1 more	65 min
Mar 1, 2:19 AM EST	Mesoscale Discussion	SPC	Cattaraugus, Chautauqua	86 min
Mar 1, 3:56 PM EST	Mesoscale Discussion	SPC	Beaver, Butler, Crawford, Lawrence, Mercer, Venango and 1 more	2 hr
Mar 1, 6:28 AM EST	Mesoscale Discussion	SPC	Dickenson, Lee, Wise	2 hr
Mar 1, 7:47 AM EST	Severe Thunderstorm Watch	SPC	Buchanan, Dickenson, Lee, Russell, Scott, Washington and 3 more	5 hr
Mar 1, 8:28 AM EST	Mesoscale Discussion	SPC	Buchanan, Dickenson, Lee, Russell, Scott, Tazewell and 2 more	92 min
Mar 1, 3:02 PM EST	Severe Thunderstorm Watch	SPC	Halifax, Pittsylvania, City of Danville	7 hr

Nearby

Mesoscale Discussions in Virginia, 2017 Mesoscale Discussions in New Jersey, 2017 Mesoscale Discussions in Maryland, 2017 Every 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.