Alert archive / Pennsylvania / Mesoscale Discussions in 2004

Mesoscale Discussion 600

May 8, 20044 states

The Storm Prediction Center issued this mesoscale discussion at May 8, 2004, 6:28 PM EDT for 4 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: May 8, 2004, 6:28 PM EDT (22:28 UTC)
Expired: May 8, 2004, 9:00 PM EDT
In force: 3 hr
Issued by: the Storm Prediction Center

All 30 counties

Chautauqua County, NY, Ashtabula County, OH, Columbiana County, OH, Geauga County, OH, Lake County, OH, Mahoning County, OH, Trumbull County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Crawford County, PA, Elk County, PA, Erie County, PA, Fayette County, PA, Forest County, PA, Greene County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, McKean County, PA, Mercer County, PA, Venango County, PA, Warren County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Hancock County, WV, Ohio County, WV

The radar

The Pittsburgh radar (KPBZ), 82 km from the middle of the area, began a volume at 22:29 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

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 10.5 hours before the alert went out and 213 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: 2233 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 223 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
May 8, 6:20 PM EDT	Severe Thunderstorm Watch	SPC	Defiance, Fulton, Henry, Lucas, Ottawa, Sandusky and 2 more	6 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2004 Mesoscale Discussions in Ohio, 2004 Mesoscale Discussions in West 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.