Alert archive / Pennsylvania / Mesoscale Discussions in 2011
Mesoscale Discussion 118
The Storm Prediction Center issued this mesoscale discussion at Feb 21, 2011, 5:58 PM EST for 7 counties in Maryland; 18 counties in Pennsylvania; Berkeley County, Morgan County, West Virginia. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 21, 2011, 5:58 PM EST (22:58 UTC)
- Expired
- Feb 21, 2011, 10:00 PM EST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
All 27 counties
Baltimore County, MD, Carroll County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Washington County, MD, Adams County, PA, Allegheny County, PA, Armstrong County, PA, Bedford County, PA, Blair County, PA, Cambria County, PA, Cumberland County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Indiana County, PA, Juniata County, PA, Lancaster County, PA, Mifflin County, PA, Perry County, PA, Somerset County, PA, Westmoreland County, PA, York County, PA, Berkeley County, WV, Morgan County, WV
The radar
The State College radar (KCCX), 91 km from the middle of the area, began a volume at 23:02 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, 11.0 hours before the alert went out and 154 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 447 m above ground
- 0-6 km bulk shear
- 77 kt
- 0-1 km storm-relative helicity
- 65 m²/s²
- 0-3 km storm-relative helicity
- 120 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 21, 6:33 PM EST | Mesoscale Discussion | SPC | Allegany, Anne Arundel, Frederick, Garrett, Howard, Montgomery and 3 more | 5 hr |
| Feb 20, 7:46 PM EST | Mesoscale Discussion | SPC | Armstrong, Blair, Bradford, Butler, Cameron, Centre and 24 more | 4 hr |
| Feb 20, 11:50 PM EST | Mesoscale Discussion | SPC | Bradford, Butler, Cambria, Cameron, Carbon, Centre and 29 more | 5 hr |
Nearby
Mesoscale Discussions in Pennsylvania, 2011Mesoscale Discussions in Maryland, 2011Mesoscale Discussions in West Virginia, 2011Every mesoscale discussion in 2011
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.