Alert archive / Pennsylvania / Mesoscale Discussions in 2019

Mesoscale Discussion 889

May 29, 20194 states

The Storm Prediction Center issued this mesoscale discussion at May 29, 2019, 3:47 PM EDT for 4 states. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: May 29, 2019, 3:47 PM EDT (19:47 UTC)
Expired: May 29, 2019, 5:45 PM EDT
In force: 118 min
Issued by: the Storm Prediction Center

All 51 counties

New Castle County, DE, Cecil County, MD, Harford County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Morris County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Adams County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Bucks County, PA, Carbon County, PA, Centre County, PA, Chester County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Mifflin 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, Union County, PA, Wyoming County, PA, York County, PA

The radar

The State College radar (KCCX), 140 km from the middle of the area, began a volume at 19:47 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, 7.8 hours before the alert went out and 171 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: 292 J/kg
Mixed-layer CIN: -123 J/kg
Mixed-layer LCL: 1463 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 30 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
May 28, 8:07 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle	113 min
May 29, 1:10 PM EDT	Tornado Watch	SPC	New Castle	8 hr
May 29, 11:52 AM EDT	Severe Thunderstorm Watch	SPC	Garrett	6 hr
May 29, 4:58 PM EDT	Mesoscale Discussion	SPC	Baltimore, Carroll, Frederick, Howard, Montgomery, City of Baltimore	3 hr
May 28, 9:31 PM EDT	Mesoscale Discussion	SPC	Essex, Hudson, Morris, Union	89 min
May 29, 12:06 PM EDT	Mesoscale Discussion	SPC	Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 3 more	84 min
May 29, 12:56 PM EDT	Severe Thunderstorm Watch	SPC	Allegheny, Armstrong, Beaver, Butler, Clarion, Fayette and 9 more	6 hr
May 29, 3:17 PM EDT	Mesoscale Discussion	SPC	Allegheny, Fayette, Greene, Somerset, Washington, Westmoreland	118 min

Nearby

Mesoscale Discussions in Pennsylvania, 2019 Mesoscale Discussions in New Jersey, 2019 Mesoscale Discussions in Maryland, 2019 Every mesoscale discussion in 2019

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.