Alert archive / Pennsylvania / Mesoscale Discussions in 2016

Mesoscale Discussion 462

April 26, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2016, 6:46 PM EDT for 4 states. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued: Apr 26, 2016, 6:46 PM EDT (22:46 UTC)
Expired: Apr 26, 2016, 7:45 PM EDT
In force: 59 min
Issued by: the Storm Prediction Center

All 36 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Talbot 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, Adams County, PA, Bedford County, PA, Berks County, PA, Blair 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, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Montgomery County, PA, Perry County, PA, Philadelphia County, PA, Somerset County, PA, York County, PA

The radar

The Sterling radar (KLWX), 94 km from the middle of the area, began a volume at 22:46 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, 10.8 hours before the alert went out and 58 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: 25 J/kg
Mixed-layer CIN: -252 J/kg
Mixed-layer LCL: 1659 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 177 m²/s²
0-3 km storm-relative helicity: 173 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
Apr 26, 1:19 PM EDT	Mesoscale Discussion	SPC	New Castle	86 min
Apr 26, 1:54 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	6 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2016 Mesoscale Discussions in New Jersey, 2016 Mesoscale Discussions in Maryland, 2016 Every mesoscale discussion in 2016

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.