Alert archive / Pennsylvania / Mesoscale Discussions in 2023
Mesoscale Discussion 1649
The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2023, 4:56 PM EDT for 4 states. It was in force for 94 min.
The area
The outline as issued.
The facts
- Issued
- Jul 20, 2023, 4:56 PM EDT (20:56 UTC)
- Expired
- Jul 20, 2023, 6:30 PM EDT
- In force
- 94 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...severe thunderstorm watch likely
- Chance of a watch
- 95%
All 49 counties
Allegany County, NY, Cattaraugus County, NY, Cayuga County, NY, Chautauqua County, NY, Erie County, NY, Genesee County, NY, Livingston County, NY, Monroe County, NY, Niagara County, NY, Ontario County, NY, Orleans County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Wayne County, NY, Wyoming County, NY, Yates County, NY, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Harrison County, OH, Jefferson County, OH, Mahoning County, OH, Tuscarawas County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Cambria County, PA, Cameron County, PA, Clarion County, PA, Clearfield County, PA, Clinton County, PA, Elk County, PA, Forest County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, McKean County, PA, Mercer County, PA, Potter County, PA, Tioga 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), 131 km from the middle of the area, began a volume at 20:59 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
Pittsburgh, PA (KPIT), launched 12:00Z, 8.9 hours before the alert went out and 139 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
- 342 J/kg
- Mixed-layer CIN
- -76 J/kg
- Mixed-layer LCL
- 842 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 82 m²/s²
- 0-3 km storm-relative helicity
- 84 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.0
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 2:15 PM EDT | Mesoscale Discussion | SPC | Cattaraugus, Chautauqua, Erie | 90 min |
| Jul 20, 6:19 PM EDT | Severe Thunderstorm Watch | SPC | Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 23 more | 9 hr |
| Jul 20, 2:45 PM EDT | Severe Thunderstorm Watch | SPC | Allen, Ashland, Ashtabula, Auglaize, Champaign, Clark and 50 more | 8 hr |
| Jul 20, 5:01 PM EDT | Mesoscale Discussion | SPC | Allen, Ashland, Auglaize, Crawford, Cuyahoga, Darke and 29 more | 89 min |
Nearby
Mesoscale Discussions in Pennsylvania, 2023Mesoscale Discussions in New York, 2023Mesoscale Discussions in Ohio, 2023Every mesoscale discussion in 2023
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.