Alert archive / Pennsylvania / Mesoscale Discussions in 2007

Mesoscale Discussion 1392

July 5, 20074 states

The Storm Prediction Center issued this mesoscale discussion at Jul 5, 2007, 11:40 AM EDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 5, 2007, 11:40 AM EDT (15:40 UTC)
Expired: Jul 5, 2007, 1:45 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 24 counties

Allegany County, MD, Garrett County, MD, Belmont County, OH, Guernsey County, OH, Harrison County, OH, Jefferson County, OH, Tuscarawas County, OH, Allegheny County, PA, Bedford County, PA, Blair County, PA, Cambria County, PA, Fayette County, PA, Fulton County, PA, Greene County, PA, Huntingdon County, PA, Indiana County, PA, Somerset County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Hancock County, WV, Marshall County, WV, Monongalia County, WV, Ohio County, WV

The radar

The Pittsburgh radar (KPBZ), 42 km from the middle of the area, began a volume at 15:40 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

Pittsburgh, PA (KPIT), launched 12:00Z, 3.7 hours before the alert went out and 26 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: 333 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 597 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 82 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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
Jul 4, 8:10 PM EDT	Mesoscale Discussion	SPC	Garrett	65 min
Jul 5, 1:59 PM EDT	Mesoscale Discussion	SPC	Allen, Ashland, Auglaize, Belmont, Butler, Carroll and 62 more	2 hr
Jul 5, 2:09 PM EDT	Severe Thunderstorm Watch	SPC	Defiance, Fulton, Henry, Williams	7 hr
Jul 5, 6:37 PM EDT	Mesoscale Discussion	SPC	Defiance, Fulton, Henry, Lucas, Paulding, Williams	53 min
Jul 5, 12:17 PM EDT	Mesoscale Discussion	SPC	McKean, Warren	118 min
Jul 5, 1:00 PM EDT	Severe Thunderstorm Watch	SPC	Bradford, Cameron, Clarion, Clinton, Crawford, Elk and 16 more	7 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2007 Mesoscale Discussions in Ohio, 2007 Mesoscale Discussions in West Virginia, 2007 Every mesoscale discussion in 2007

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.