Alert archive / Pennsylvania / Mesoscale Discussions in 2020

Mesoscale Discussion 804

June 3, 2020New Castle County, Delaware; 6 counties in New Jersey; 12 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Jun 3, 2020, 7:44 PM EDT for New Castle County, Delaware; 6 counties in New Jersey; 12 counties in Pennsylvania. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: Jun 3, 2020, 7:44 PM EDT (23:44 UTC)
Expired: Jun 3, 2020, 9:15 PM EDT
In force: 91 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 244

Counties New Castle County, DE, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Ocean County, NJ, Salem County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Lancaster County, PA, Lebanon County, PA, Montgomery County, PA, Perry County, PA, Philadelphia County, PA, York County, PA

The radar

The Philadelphia radar (KDIX), 107 km from the middle of the area, began a volume at 23:47 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.7 hours before the alert went out and 195 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: 2031 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 273 m²/s²
0-3 km storm-relative helicity: 269 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Jun 3, 10:08 AM EDT	Severe Thunderstorm Watch	SPC	New Castle	4 hr
Jun 3, 11:34 AM EDT	Mesoscale Discussion	SPC	New Castle	86 min
Jun 3, 3:52 PM EDT	Severe Thunderstorm Watch	SPC	New Castle	6 hr
Jun 3, 6:58 PM EDT	Mesoscale Discussion	SPC	Bergen, Essex, Hudson, Hunterdon, Mercer, Middlesex and 7 more	92 min
Jun 2, 9:26 PM EDT	Mesoscale Discussion	SPC	McKean, Potter, Tioga, Warren	3 hr
Jun 3, 5:12 AM EDT	Mesoscale Discussion	SPC	Crawford, Erie, Forest, McKean, Warren	2 hr
Jun 3, 8:32 AM EDT	Mesoscale Discussion	SPC	Adams, Armstrong, Berks, Blair, Bradford, Butler and 38 more	118 min
Jun 3, 3:10 PM EDT	Mesoscale Discussion	SPC	Adams, Allegheny, Armstrong, Beaver, Bedford, Blair and 32 more	2 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2020 Mesoscale Discussions in New Jersey, 2020 Mesoscale Discussions in Delaware, 2020 Every 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.