Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 413
The Storm Prediction Center issued this severe thunderstorm watch at Jul 13, 2017, 2:57 PM EDT for 10 counties in New Jersey; 23 counties in Pennsylvania. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 13, 2017, 2:57 PM EDT (18:57 UTC)
- Expired
- Jul 13, 2017, 8:50 PM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 33 counties
Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Somerset County, NJ, Warren County, NJ, 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, 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, Perry County, PA, Philadelphia County, PA, Pike County, PA, Schuylkill County, PA, York County, PA
The radar
The Philadelphia radar (KDIX), 145 km from the middle of the area, began a volume at 18:59 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 5%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- 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
12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 13, 4:15 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 60 min |
| Jul 13, 4:50 PM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer, Middlesex, Monmouth, Morris, Somerset | 55 min |
| Jul 13, 4:50 PM EDT | Severe Thunderstorm Warning | PHI | Burlington | 40 min |
| Jul 13, 5:08 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Montgomery | 35 min |
| Jul 13, 5:08 PM EDT | Tornado Warning | PHI | Berks | 22 min |
| Jul 13, 5:21 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Mercer, Middlesex, Monmouth, Ocean | 54 min |
| Jul 13, 5:25 PM EDT | Flash Flood Warning | PHI | Berks, Lehigh | 3 hr |
| Jul 13, 5:26 PM EDT | Tornado Warning | PHI | Berks, Chester, Montgomery | 28 min |
| Jul 13, 5:31 PM EDT | Flash Flood Warning | PHI | Burlington, Mercer, Middlesex, Monmouth, Ocean | 3 hr |
| Jul 13, 5:44 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery | 46 min |
| Jul 13, 6:07 PM EDT | Severe Thunderstorm Warning | PHI | Monmouth, Ocean | 25 min |
| Jul 13, 6:44 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Monmouth, Ocean | 45 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, 7.0 hours before the alert went out and 199 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
- 135 J/kg
- Mixed-layer CIN
- -77 J/kg
- Mixed-layer LCL
- 1715 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 49 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 |
|---|---|---|---|---|
| Jul 13, 11:09 AM EDT | Mesoscale Discussion | SPC | Atlantic, Bergen, Burlington, Camden, Cape May, Cumberland and 15 more | 2 hr |
| Jul 13, 1:57 PM EDT | Severe Thunderstorm Watch | SPC | Bergen, Essex, Hudson, Morris, Passaic, Sussex and 1 more | 5 hr |
| Jul 13, 2:33 PM EDT | Mesoscale Discussion | SPC | Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 3 more | 57 min |
| Jul 13, 4:43 PM EDT | Mesoscale Discussion | SPC | Bergen, Burlington, Camden, Essex, Gloucester, Hudson and 10 more | 62 min |
| Jul 13, 6:23 PM EDT | Mesoscale Discussion | SPC | Burlington, Camden, Gloucester, Ocean | 97 min |
Nearby
Severe Thunderstorm Watches in Pennsylvania, 2017Severe Thunderstorm Watches in New Jersey, 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.