Alert archive / Pennsylvania / Mesoscale Discussions in 2020
Mesoscale Discussion 1801
The Storm Prediction Center issued this mesoscale discussion at Nov 15, 2020, 3:33 PM EST for 7 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 15, 2020, 3:33 PM EST (20:33 UTC)
- Expired
- Nov 15, 2020, 6:00 PM EST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 60%
All 107 counties
Kent County, DE, New Castle County, DE, Sussex County, DE, Berkshire County, MA, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Talbot County, MD, Wicomico 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, Albany County, NY, Bronx County, NY, Broome County, NY, Columbia County, NY, Delaware County, NY, Dutchess County, NY, Greene 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, Schoharie County, NY, Sullivan County, NY, Ulster County, NY, Westchester County, NY, Adams County, PA, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Philadelphia County, PA, Pike County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Manassas, VA, City of Manassas Park, VA, Fairfax County, VA, Fauquier County, VA, King George County, VA, Loudoun County, VA, Prince William County, VA, Richmond County, VA, Stafford County, VA, Westmoreland County, VA
The radar
The Philadelphia radar (KDIX), 128 km from the middle of the area, began a volume at 20:35 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
Washington/Dulle, VA (KIAD), launched 12:00Z, 8.6 hours before the alert went out and 237 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 843 m above ground
- 0-6 km bulk shear
- 59 kt
- 0-1 km storm-relative helicity
- 199 m²/s²
- 0-3 km storm-relative helicity
- 356 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 15, 5:35 PM EST | Severe Thunderstorm Watch | SPC | Kent, New Castle, Sussex | 5 hr |
| Nov 15, 6:52 PM EST | Mesoscale Discussion | SPC | Kent, New Castle, Sussex | 113 min |
| Nov 15, 1:16 PM EST | Mesoscale Discussion | SPC | Cattaraugus, Chautauqua, Erie, Genesee, Niagara, Wyoming | 89 min |
| Nov 15, 1:57 PM EST | Severe Thunderstorm Watch | SPC | Allegany, Cattaraugus, Chautauqua, Erie, Genesee, Livingston and 9 more | 4 hr |
| Nov 15, 4:20 PM EST | Mesoscale Discussion | SPC | Cayuga, Chemung, Cortland, Jefferson, Lewis, Madison and 7 more | 85 min |
| Nov 15, 6:27 PM EST | Mesoscale Discussion | SPC | Albany, Cayuga, Chenango, Cortland, Delaware, Essex and 20 more | 3 hr |
| Nov 15, 11:33 AM EST | Mesoscale Discussion | SPC | Crawford, Erie, Lawrence, Mercer, Venango | 57 min |
| Nov 15, 11:51 AM EST | Severe Thunderstorm Watch | SPC | Beaver, Butler, Crawford, Erie, Lawrence, Mercer and 1 more | 3 hr |
Nearby
Mesoscale Discussions in Pennsylvania, 2020Mesoscale Discussions in New Jersey, 2020Mesoscale Discussions in Maryland, 2020Every mesoscale discussion in 2020
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.