Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 464
The Storm Prediction Center issued this severe thunderstorm watch at Aug 22, 2017, 4:19 PM EDT for 4 states. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 22, 2017, 4:19 PM EDT (20:19 UTC)
- Expired
- Aug 23, 2017, 12:00 AM EDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 55 counties
Greater Bridgeport Planning Region, CT, Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Essex County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Passaic County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Delaware County, NY, Orange County, NY, Putnam County, NY, Rockland County, NY, Sullivan County, NY, Westchester County, NY, Adams County, PA, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Franklin County, PA, Fulton County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Mifflin County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Philadelphia County, PA, Pike County, PA, Schuylkill County, PA, Snyder County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA, York County, PA
The radar
The Philadelphia radar (KDIX), 163 km from the middle of the area, began a volume at 20:20 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
- 10%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
27 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 22, 7:00 PM EDT | Severe Thunderstorm Warning | BGM | Luzerne, Wyoming | 45 min |
| Aug 22, 7:23 PM EDT | Severe Thunderstorm Warning | CTP | Dauphin, Lebanon, Schuylkill | 67 min |
| Aug 22, 7:24 PM EDT | Severe Thunderstorm Warning | CTP | Columbia | 21 min |
| Aug 22, 7:30 PM EDT | Severe Thunderstorm Warning | BGM | Luzerne | 45 min |
| Aug 22, 7:33 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 42 min |
| Aug 22, 7:43 PM EDT | Severe Thunderstorm Warning | BGM | Lackawanna, Luzerne, Wayne | 47 min |
| Aug 22, 7:57 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe | 48 min |
| Aug 22, 7:59 PM EDT | Tornado Warning | BGM | Luzerne | 31 min |
| Aug 22, 7:59 PM EDT | Severe Thunderstorm Warning | CTP | Dauphin, Lebanon | 46 min |
| Aug 22, 7:59 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Carbon, Lehigh | 46 min |
| Aug 22, 8:12 PM EDT | Severe Thunderstorm Warning | PHI | Sussex, Warren | 48 min |
| Aug 22, 8:15 PM EDT | Tornado Warning | PHI | Warren | 30 min |
| Aug 22, 8:23 PM EDT | Severe Thunderstorm Warning | BGM | Sullivan | 37 min |
| Aug 22, 8:28 PM EDT | Severe Thunderstorm Warning | BGM | Lackawanna, Luzerne, Pike, Wayne | 47 min |
| Aug 22, 8:45 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Somerset, Warren | 60 min |
| Aug 22, 8:56 PM EDT | Severe Thunderstorm Warning | BGM | Sullivan | 19 min |
| Aug 22, 8:58 PM EDT | Severe Thunderstorm Warning | PHI | Sussex, Warren | 24 min |
| Aug 22, 9:00 PM EDT | Severe Thunderstorm Warning | BGM | Sullivan | 15 min |
| Aug 22, 9:02 PM EDT | Severe Thunderstorm Warning | OKX | Orange | 43 min |
| Aug 22, 9:23 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Montgomery | 52 min |
| Aug 22, 9:40 PM EDT | Tornado Warning | PHI | Berks, Chester, Montgomery | 20 min |
| Aug 22, 9:42 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer, Middlesex, Morris, Somerset, Warren | 48 min |
| Aug 22, 10:07 PM EDT | Severe Thunderstorm Warning | PHI | Gloucester, Salem | 53 min |
| Aug 22, 10:27 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer, Middlesex, Monmouth, Somerset | 48 min |
| Aug 22, 10:58 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Camden, Cumberland, Gloucester, Mercer, Middlesex and 1 more | 62 min |
| Aug 22, 11:42 PM EDT | Flash Flood Warning | PHI | Hunterdon, Middlesex, Somerset | 4 hr |
| Aug 22, 11:46 PM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Burlington, Camden, Gloucester, Ocean, Salem | 44 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
Washington/Dulle, VA (KIAD), launched 12:00Z, 8.3 hours before the alert went out and 226 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
- 306 J/kg
- Mixed-layer CIN
- -96 J/kg
- Mixed-layer LCL
- 1320 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 58 m²/s²
- 0-3 km storm-relative helicity
- 75 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 22, 3:55 PM EDT | Severe Thunderstorm Watch | SPC | Capitol Planning Region, Northwest Hills Planning Region | 8 hr |
| Aug 22, 7:07 PM EDT | Mesoscale Discussion | SPC | 113 min | |
| Aug 22, 5:49 PM EDT | Mesoscale Discussion | SPC | Berkshire, Franklin, Hampden, Hampshire | 116 min |
| Aug 22, 3:08 PM EDT | Mesoscale Discussion | SPC | Bergen, Essex, Hunterdon, Morris, Passaic, Somerset and 2 more | 67 min |
| Aug 22, 11:55 AM EDT | Mesoscale Discussion | SPC | Allegany, Broome, Cattaraugus, Cayuga, Chemung, Chenango and 23 more | 3 hr |
| Aug 22, 12:23 PM EDT | Tornado Watch | SPC | Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 36 more | 9 hr |
| Aug 22, 2:44 PM EDT | Mesoscale Discussion | SPC | Allegany, Broome, Cayuga, Chemung, Chenango, Clinton and 22 more | 2 hr |
| Aug 22, 4:48 PM EDT | Mesoscale Discussion | SPC | Broome, Cayuga, Chemung, Chenango, Clinton, Cortland and 21 more | 87 min |
| Aug 22, 11:54 AM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Greene and 5 more | 66 min |
| Aug 22, 12:39 PM EDT | Severe Thunderstorm Watch | SPC | Allegheny, Armstrong, Beaver, Bedford, Blair, Butler and 16 more | 8 hr |
| Aug 22, 2:44 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Blair, Butler, Cambria and 13 more | 91 min |
| Aug 22, 4:39 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Blair, Butler, Cambria and 13 more | 66 min |
Nearby
Severe Thunderstorm Watches in Pennsylvania, 2017Severe Thunderstorm Watches in New Jersey, 2017Severe Thunderstorm Watches in New York, 2017Every severe thunderstorm watch in 2017
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.