Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 755
The Storm Prediction Center issued this severe thunderstorm watch at Aug 9, 2011, 4:16 PM EDT for 14 counties in New Jersey; 17 counties in New York; 25 counties in Pennsylvania. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 9, 2011, 4:16 PM EDT (20:16 UTC)
- Expired
- Aug 9, 2011, 9:00 PM EDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 56 counties
Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Essex County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Broome County, NY, Chenango County, NY, Delaware County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Herkimer County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Orange County, NY, Otsego County, NY, Rockland County, NY, Schoharie County, NY, Sullivan County, NY, Tioga County, NY, Ulster County, NY, Berks County, PA, Bradford County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Delaware County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Philadelphia County, PA, Pike County, PA, Schuylkill County, PA, Sullivan County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA, York County, PA
The radar
The Binghamton radar (KBGM), 45 km from the middle of the area, began a volume at 20:19 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 9, 4:45 PM EDT | Severe Thunderstorm Warning | BGM | Chenango, Delaware, Otsego | 60 min |
| Aug 9, 5:39 PM EDT | Severe Thunderstorm Warning | BGM | Delaware, Otsego | 81 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Albany, NY (KALY), launched 12:00Z, 8.3 hours before the alert went out and 151 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
- 4 J/kg
- Mixed-layer CIN
- -128 J/kg
- Mixed-layer LCL
- 1039 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- -5 m²/s²
- 0-3 km storm-relative helicity
- 64 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 |
|---|---|---|---|---|
| Aug 9, 12:48 PM EDT | Mesoscale Discussion | SPC | Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 3 more | 57 min |
| Aug 9, 3:05 PM EDT | Mesoscale Discussion | SPC | Bergen, Burlington, Camden, Essex, Gloucester, Hudson and 10 more | 55 min |
| Aug 9, 7:07 PM EDT | Mesoscale Discussion | SPC | Burlington, Camden, Cumberland, Gloucester, Hunterdon, Mercer and 6 more | 83 min |
| Aug 9, 6:56 PM EDT | Severe Thunderstorm Watch | SPC | Crawford, Erie, Lawrence, Mercer | 5 hr |
Nearby
Severe Thunderstorm Watches in Pennsylvania, 2011Severe Thunderstorm Watches in New York, 2011Severe Thunderstorm Watches in New Jersey, 2011Every severe thunderstorm watch 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.