Alert archive / Pennsylvania / Mesoscale Discussions in 2004

Mesoscale Discussion 1272

June 14, 20045 states

The Storm Prediction Center issued this mesoscale discussion at Jun 14, 2004, 4:45 PM EDT for 5 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 14, 2004, 4:45 PM EDT (20:45 UTC)
Expired: Jun 14, 2004, 6:45 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 34 counties

New Castle County, DE, Baltimore County, MD, Carroll County, MD, Cecil County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Washington County, MD, Adams County, PA, Berks County, PA, Bucks County, PA, Chester County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Franklin County, PA, Fulton County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Montgomery County, PA, Perry County, PA, Philadelphia County, PA, York County, PA, City of Winchester, VA, Clarke County, VA, Frederick County, VA, Loudoun County, VA, Berkeley County, WV, Jefferson County, WV, Morgan County, WV

The radar

The Sterling radar (KLWX), 106 km from the middle of the area, began a volume at 20:46 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 473Jun 14, 7:15 PM EDT

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.8 hours before the alert went out and 80 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: 750 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 277 m²/s²
0-3 km storm-relative helicity: 272 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 14, 7:15 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Baltimore, Carroll, Frederick, Garrett, Harford and 4 more	4 hr
Jun 13, 8:30 PM EDT	Mesoscale Discussion	SPC	Crawford, Erie	90 min
Jun 13, 11:08 PM EDT	Mesoscale Discussion	SPC	Beaver, Butler, Crawford, Erie, Forest, Lawrence and 3 more	97 min
Jun 13, 11:45 PM EDT	Severe Thunderstorm Watch	SPC	Allegheny, Beaver, Butler, Lawrence, Mercer, Venango and 1 more	4 hr
Jun 14, 2:40 AM EDT	Mesoscale Discussion	SPC	Allegheny, Beaver, Washington	2 hr
Jun 14, 11:22 AM EDT	Mesoscale Discussion	SPC	Beaver, Butler, Clarion, Crawford, Elk, Erie and 8 more	53 min
Jun 14, 3:20 PM EDT	Mesoscale Discussion	SPC	Cameron, Clarion, Crawford, Elk, Erie, Forest and 6 more	115 min
Jun 14, 5:00 PM EDT	Severe Thunderstorm Watch	SPC	Armstrong, Beaver, Butler, Cameron, Clarion, Crawford and 11 more	6 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2004 Mesoscale Discussions in Maryland, 2004 Mesoscale Discussions in Virginia, 2004 Every mesoscale discussion in 2004

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.