Alert archive / New Jersey / Mesoscale Discussions in 2017

Mesoscale Discussion 462

April 6, 20177 states

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2017, 3:12 PM EDT for 7 states. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: Apr 6, 2017, 3:12 PM EDT (19:12 UTC)
Expired: Apr 6, 2017, 4:15 PM EDT
In force: 63 min
Issued by: the Storm Prediction Center

All 33 counties

Kent County, DE, New Castle County, DE, Bristol County, MA, Dukes County, MA, Cecil County, MD, Kent County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester 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, Suffolk County, NY, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA, Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI

The radar

The Philadelphia radar (KDIX), 73 km from the middle of the area, began a volume at 19:16 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, 7.2 hours before the alert went out and 94 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: 8 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 428 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 407 m²/s²
0-3 km storm-relative helicity: 569 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 6, 12:18 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	57 min
Apr 6, 12:45 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	4 hr
Apr 6, 5:59 AM EDT	Mesoscale Discussion	SPC	Calvert, Charles, Dorchester, Saint Mary's	91 min
Apr 6, 7:06 AM EDT	Tornado Watch	SPC	Dorchester, Somerset, Wicomico, Worcester	8 hr

Nearby

Mesoscale Discussions in New Jersey, 2017 Mesoscale Discussions in New York, 2017 Mesoscale Discussions in Connecticut, 2017 Every 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.