Alert archive / Pennsylvania / Tornado Watches in 2024
Tornado Watch 616
The Storm Prediction Center issued this tornado watch at Aug 9, 2024, 6:17 AM EDT for 6 states. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 9, 2024, 6:17 AM EDT (10:17 UTC)
- Expired
- Aug 9, 2024, 2:00 PM EDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Strongest gust expected
- 50 kt
All 100 counties
Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Essex County, NJ, Gloucester 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, Orange County, NY, Sullivan County, NY, Adams County, PA, Berks County, PA, Bradford County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming 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, Sullivan County, PA, Susquehanna County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA, York County, PA, Accomack County, VA, Arlington County, VA, Caroline County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Manassas, VA, City of Manassas Park, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Loudoun County, VA, Middlesex County, VA, Northumberland County, VA, Prince William County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Westmoreland County, VA
The radar
The Philadelphia radar (KDIX), 101 km from the middle of the area, began a volume at 10:17 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
- 50%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 20%
- 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
- 40%
Warnings issued inside it
24 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 9, 6:22 AM EDT | Tornado Warning | LWX | Arlington, Fairfax, Prince William, City of Alexandria | 23 min |
| Aug 9, 6:37 AM EDT | Flash Flood Warning | LWX | Montgomery | 2 hr |
| Aug 9, 7:00 AM EDT | Flash Flood Warning | LWX | Montgomery | 4 hr |
| Aug 9, 7:06 AM EDT | Flash Flood Warning | CTP | Lycoming, Union | 2 hr |
| Aug 9, 7:40 AM EDT | Tornado Warning | LWX | Carroll, Howard, Montgomery | 20 min |
| Aug 9, 7:48 AM EDT | Tornado Warning | LWX | Charles, Prince George's | 27 min |
| Aug 9, 7:52 AM EDT | Flash Flood Warning | BGM | Susquehanna | 8 hr |
| Aug 9, 7:52 AM EDT | Flash Flood Warning | CTP | Lycoming, Tioga | 2 hr |
| Aug 9, 8:00 AM EDT | Flash Flood Warning | LWX | Montgomery, Prince George's | 3 hr |
| Aug 9, 8:04 AM EDT | Tornado Warning | LWX | Carroll | 26 min |
| Aug 9, 8:23 AM EDT | Tornado Warning | LWX | Prince George's | 11 min |
| Aug 9, 8:27 AM EDT | Flash Flood Warning | LWX | Anne Arundel, Howard, Montgomery, Prince George's | 3 hr |
| Aug 9, 8:27 AM EDT | Tornado Warning | CTP | Adams, York | 33 min |
| Aug 9, 8:44 AM EDT | Flash Flood Warning | CTP | Adams, York | 2 hr |
| Aug 9, 8:48 AM EDT | Flash Flood Warning | LWX | Baltimore, Carroll, Frederick, Howard | 95 min |
| Aug 9, 8:57 AM EDT | Tornado Warning | LWX | Carroll | 18 min |
| Aug 9, 9:18 AM EDT | Flash Flood Warning | CTP | Cumberland, Dauphin, York | 117 min |
| Aug 9, 10:07 AM EDT | Flash Flood Warning | CTP | York | 113 min |
| Aug 9, 10:42 AM EDT | Tornado Warning | BGM | Susquehanna | 18 min |
| Aug 9, 11:33 AM EDT | Flash Flood Warning | BGM | Bradford, Luzerne, Susquehanna, Wyoming | 4 hr |
| Aug 9, 12:34 PM EDT | Flash Flood Warning | CTP | Lycoming | 116 min |
| Aug 9, 12:45 PM EDT | Flash Flood Warning | BGM | Lackawanna, Luzerne, Wyoming | 4 hr |
| Aug 9, 12:45 PM EDT | Flash Flood Warning | CTP | Sullivan | 3 hr |
| Aug 9, 1:33 PM EDT | Flash Flood Warning | BGM | Susquehanna, Wayne | 4 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
Washington/Dulle, VA (KIAD), launched 00:00Z, 10.3 hours before the alert went out and 214 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
- 886 J/kg
- Mixed-layer CIN
- -5 J/kg
- Mixed-layer LCL
- 607 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 70 m²/s²
- 0-3 km storm-relative helicity
- 132 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.4
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 9, 10:26 AM EDT | Mesoscale Discussion | SPC | Kent, New Castle, Sussex | 94 min |
| Aug 8, 8:38 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Calvert, Charles, Frederick, Harford and 6 more | 2 hr |
| Aug 8, 11:04 PM EDT | Mesoscale Discussion | SPC | Baltimore, Carroll, Cecil, Frederick, Harford, Howard and 3 more | 116 min |
| Aug 9, 4:38 AM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Calvert, Carroll, Cecil, Charles and 11 more | 3 hr |
| Aug 9, 1:27 PM EDT | Tornado Watch | SPC | Bergen, Essex, Hunterdon, Mercer, Middlesex, Morris and 5 more | 7 hr |
| Aug 9, 2:27 PM EDT | Mesoscale Discussion | SPC | Albany, Columbia, Greene, Rensselaer, Schenectady | 93 min |
| Aug 9, 4:57 PM EDT | Mesoscale Discussion | SPC | Columbia, Rensselaer, Washington | 93 min |
Nearby
Tornado Watches in Pennsylvania, 2024Tornado Watches in Virginia, 2024Tornado Watches in Maryland, 2024Every tornado watch in 2024
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.