Alert archive / Virginia / Mesoscale Discussions in 2014

Mesoscale Discussion 143

February 21, 20145 states

The Storm Prediction Center issued this mesoscale discussion at Feb 21, 2014, 12:16 PM EST for 5 states. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Feb 21, 2014, 12:16 PM EST (17:16 UTC)
Expired: Feb 21, 2014, 1:45 PM EST
In force: 89 min
Issued by: the Storm Prediction Center

All 59 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Cecil County, MD, City of Baltimore, MD, Dorchester County, MD, Harford County, MD, Kent County, MD, Queen Anne's County, MD, Saint Mary'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, Ocean County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Philadelphia County, PA, Accomack County, VA, Charles City County, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Williamsburg, VA, Essex County, VA, Gloucester County, VA, Isle of Wight 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, Southampton County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Dover AFB radar (KDOX), 50 km from the middle of the area, began a volume at 17:17 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.

Tornado Watch 26Feb 21, 12:40 PM EST

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 5.3 hours before the alert went out and 108 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 599 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 206 m²/s²
0-3 km storm-relative helicity: 212 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 21, 10:39 AM EST	Tornado Watch	SPC	Kent, New Castle, Sussex	5 hr
Feb 21, 2:07 PM EST	Mesoscale Discussion	SPC	Sussex	53 min
Feb 21, 12:38 PM EST	Tornado Watch	SPC	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 7 more	3 hr
Feb 20, 10:29 PM EST	Mesoscale Discussion	SPC	Lee	61 min
Feb 20, 10:47 PM EST	Tornado Watch	SPC	Lee, Russell, Scott, Washington, Wise, City of Bristol and 1 more	6 hr
Feb 21, 3:11 AM EST	Mesoscale Discussion	SPC	Bland, Grayson, Smyth, Tazewell, Washington, Wythe and 1 more	94 min
Feb 21, 8:57 AM EST	Mesoscale Discussion	SPC	Amelia, Appomattox, Brunswick, Buckingham, Campbell, Charlotte and 10 more	63 min

Nearby

Mesoscale Discussions in Virginia, 2014 Mesoscale Discussions in Maryland, 2014 Mesoscale Discussions in New Jersey, 2014 Every mesoscale discussion in 2014

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.