Alert archive / Pennsylvania / Mesoscale Discussions in 2020
Mesoscale Discussion 823
The Storm Prediction Center issued this mesoscale discussion at Jun 4, 2020, 6:44 PM EDT for 25 counties in Pennsylvania. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Jun 4, 2020, 6:44 PM EDT (22:44 UTC)
- Expired
- Jun 4, 2020, 8:15 PM EDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 250
All 25 counties
Adams County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Centre County, PA, Chester County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Mifflin County, PA, Montgomery County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Union County, PA, York County, PA
The radar
The State College radar (KCCX), 99 km from the middle of the area, began a volume at 22:47 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
Washington/Dulle, VA (KIAD), launched 12:00Z, 10.7 hours before the alert went out and 185 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
- 139 J/kg
- Mixed-layer CIN
- -204 J/kg
- Mixed-layer LCL
- 1499 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- -64 m²/s²
- 0-3 km storm-relative helicity
- 54 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
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 |
|---|---|---|---|---|
| Jun 4, 12:45 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Fayette and 5 more | 90 min |
| Jun 4, 12:55 PM EDT | Severe Thunderstorm Watch | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Fayette and 6 more | 6 hr |
| Jun 4, 2:02 PM EDT | Mesoscale Discussion | SPC | Adams, Cumberland, Franklin, Fulton, Perry, York | 118 min |
| Jun 4, 2:14 PM EDT | Mesoscale Discussion | SPC | Beaver, Lawrence, Washington | 61 min |
| Jun 4, 2:29 PM EDT | Severe Thunderstorm Watch | SPC | Adams, Bedford, Blair, Cambria, Cameron, Centre and 22 more | 8 hr |
| Jun 4, 4:00 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Greene and 4 more | 90 min |
| Jun 4, 4:41 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Blair, Cambria, Centre, Clinton and 16 more | 94 min |
Nearby
Mesoscale Discussions in Pennsylvania, 2020Every mesoscale discussion in 2020
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.