Alert archive / Pennsylvania / Mesoscale Discussions in 2007

Mesoscale Discussion 1066

June 8, 20074 states

The Storm Prediction Center issued this mesoscale discussion at Jun 8, 2007, 4:12 PM EDT for 4 states. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Jun 8, 2007, 4:12 PM EDT (20:12 UTC)
Expired
Jun 8, 2007, 5:45 PM EDT
In force
93 min
Issued by
the Storm Prediction Center
All 75 counties

Allegany County, MD, Anne Arundel County, MD, Baltimore County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Frederick County, MD, Garrett County, MD, Harford County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Washington County, MD, Adams County, PA, Bedford County, PA, Berks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Fulton 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, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Union County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, Highland County, VA, Loudoun County, VA, Madison County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Pendleton County, WV, Randolph County, WV, Tucker County, WV

The radar

The Sterling radar (KLWX), 82 km from the middle of the area, began a volume at 20:16 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 watches that followed

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.2 hours before the alert went out and 83 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-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2007-06-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 709 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2007-06-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
709 J/kg
Mixed-layer CIN
-176 J/kg
Mixed-layer LCL
1315 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
95 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.

IssuedProductOfficeCountiesLasted
Jun 8, 5:32 PM EDTSevere Thunderstorm WatchSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more5 hr
Jun 8, 7:48 PM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Carroll, Frederick, Harford, Howard and 4 more117 min
Jun 8, 12:37 PM EDTSevere Thunderstorm WatchSPCAllegheny, Beaver, Fayette, Greene, Washington, Westmoreland8 hr
Jun 8, 2:08 PM EDTMesoscale DiscussionSPCArmstrong, Butler, Cameron, Clarion, Clearfield, Crawford and 10 more97 min
Jun 8, 2:59 PM EDTSevere Thunderstorm WatchSPCArmstrong, Bedford, Blair, Bradford, Butler, Cambria and 22 more7 hr
Jun 8, 3:06 PM EDTMesoscale DiscussionSPCAllegheny, Beaver, Fayette, Greene, Washington, Westmoreland54 min
Jun 8, 12:02 PM EDTMesoscale DiscussionSPCBuchanan, Dickenson, Lee, Russell, Scott, Tazewell and 3 more58 min

Nearby

Mesoscale Discussions in Pennsylvania, 2007Mesoscale Discussions in Virginia, 2007Mesoscale Discussions in Maryland, 2007Every 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.