Alert archive / Pennsylvania / Mesoscale Discussions in 2017
Mesoscale Discussion 1108
The Storm Prediction Center issued this mesoscale discussion at Jun 21, 2017, 2:38 PM EDT for 7 states. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 21, 2017, 2:38 PM EDT (18:38 UTC)
- Expired
- Jun 21, 2017, 5:15 PM EDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
All 95 counties
Kent County, DE, New Castle County, DE, Allegany County, MD, Anne Arundel County, MD, Baltimore County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, City of Baltimore, MD, Frederick County, MD, Garrett County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Talbot County, MD, Washington County, MD, Atlantic County, NJ, Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Essex County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Passaic County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Bronx County, NY, Dutchess County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Putnam County, NY, Queens County, NY, Richmond County, NY, Rockland County, NY, Suffolk County, NY, Westchester County, NY, Adams County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Bucks County, PA, Cambria County, PA, Carbon County, PA, Chester County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Fayette County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Indiana County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Mifflin County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Philadelphia County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Westmoreland County, PA, York County, PA, Arlington County, VA, City of Falls Church, VA, City of Winchester, VA, Clarke County, VA, Frederick County, VA, Loudoun County, VA, Berkeley County, WV, Hampshire County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV
The radar
The Philadelphia radar (KDIX), 105 km from the middle of the area, began a volume at 18:40 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
Brookhaven, NY (KOKX), launched 12:00Z, 6.6 hours before the alert went out and 228 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.
- Mixed-layer CAPE
- 23 J/kg
- Mixed-layer CIN
- -90 J/kg
- Mixed-layer LCL
- 1706 m above ground
- 0-6 km bulk shear
- 67 kt
- 0-1 km storm-relative helicity
- -3 m²/s²
- 0-3 km storm-relative helicity
- 97 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted.
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Mesoscale Discussions in Pennsylvania, 2017Mesoscale Discussions in New Jersey, 2017Mesoscale Discussions in Maryland, 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.