Alert archive / Virginia / Mesoscale Discussions in 2014

Mesoscale Discussion 1397

July 15, 20146 states

The Storm Prediction Center issued this mesoscale discussion at Jul 15, 2014, 7:04 PM EDT for 6 states. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued: Jul 15, 2014, 7:04 PM EDT (23:04 UTC)
Expired: Jul 15, 2014, 8:00 PM EDT
In force: 56 min
Issued by: the Storm Prediction Center

All 53 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Calvert County, MD, Caroline County, MD, Cecil County, MD, Charles County, MD, Dorchester County, MD, Kent County, MD, Prince George's 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, Hudson County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Salem County, NJ, Bronx County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Queens County, NY, Richmond County, NY, Delaware County, PA, Philadelphia County, PA, Arlington County, VA, Caroline County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, Essex County, VA, Fairfax County, VA, King and Queen County, VA, King George County, VA, Lancaster County, VA, Northumberland County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Westmoreland County, VA

The radar

The Philadelphia radar (KDIX), 76 km from the middle of the area, began a volume at 23:06 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 11.1 hours before the alert went out and 81 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: 1120 J/kg
Mixed-layer CIN: -68 J/kg
Mixed-layer LCL: 730 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 3.4

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
Jul 15, 1:43 PM EDT	Severe Thunderstorm Watch	SPC	Greater Bridgeport Planning Region, Naugatuck Valley Planning Region	7 hr
Jul 15, 1:51 PM EDT	Mesoscale Discussion	SPC		114 min
Jul 15, 4:41 PM EDT	Mesoscale Discussion	SPC		94 min
Jul 15, 1:23 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	97 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.