Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2003
Severe Thunderstorm Watch 809
The Storm Prediction Center issued this severe thunderstorm watch at Jul 27, 2003, 6:05 PM EDT for 37 counties in Pennsylvania. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 27, 2003, 6:05 PM EDT (22:05 UTC)
- Expired
- Jul 27, 2003, 11:00 PM EDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 37 counties
Adams County, PA, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Butler County, PA, Cambria County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Fayette County, PA, Franklin County, PA, Fulton County, PA, Greene County, PA, Huntingdon County, PA, Indiana County, PA, Jefferson County, PA, Juniata County, PA, Lancaster County, PA, Lawrence County, PA, Lebanon County, PA, Mifflin County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Union County, PA, Washington County, PA, Westmoreland County, PA, York County, PA
The radar
The State College radar (KCCX), 67 km from the middle of the area, began a volume at 22:07 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.
Warnings issued inside it
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 27, 6:42 PM EDT | Flash Flood Warning | PBZ | Lawrence, Mercer | 2 hr |
| Jul 27, 7:26 PM EDT | Flash Flood Warning | PBZ | Butler | 3 hr |
| Jul 27, 7:35 PM EDT | Flash Flood Warning | PBZ | Clarion, Jefferson | 3 hr |
| Jul 27, 8:37 PM EDT | Flash Flood Warning | CTP | Clearfield | 3 hr |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Pittsburgh, PA (KPIT), launched 12:00Z, 10.1 hours before the alert went out and 122 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
- 15 J/kg
- Mixed-layer CIN
- -274 J/kg
- Mixed-layer LCL
- 903 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 99 m²/s²
- 0-3 km storm-relative helicity
- 123 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 27, 4:31 PM EDT | Mesoscale Discussion | SPC | Blair, Carbon, Centre, Clearfield, Clinton, Columbia and 14 more | 89 min |
| Jul 27, 5:40 PM EDT | Mesoscale Discussion | SPC | Adams, Allegheny, Armstrong, Beaver, Bedford, Blair and 29 more | 2 hr |
Nearby
Severe Thunderstorm Watches in Pennsylvania, 2003Every severe thunderstorm watch in 2003
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.