Alert archive / Virginia / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 414
The Storm Prediction Center issued this severe thunderstorm watch at Jul 14, 2017, 1:40 PM EDT for 6 states. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 14, 2017, 1:40 PM EDT (17:40 UTC)
- Expired
- Jul 14, 2017, 9:00 PM EDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 76 counties
Kent County, DE, New Castle County, DE, Sussex County, DE, Allegany County, MD, 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, 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, Talbot County, MD, Washington County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Ocean County, NJ, Salem County, NJ, Adams County, PA, Bedford County, PA, Chester County, PA, Cumberland County, PA, Delaware County, PA, Franklin County, PA, Fulton County, PA, Lancaster County, PA, Philadelphia County, PA, Somerset County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, King George County, VA, Loudoun County, VA, Madison County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Pendleton County, WV
The radar
The Sterling radar (KLWX), 62 km from the middle of the area, began a volume at 17:42 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
- 2%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
29 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 14, 2:16 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, City of Winchester | 28 min |
| Jul 14, 2:31 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 59 min |
| Jul 14, 2:53 PM EDT | Flash Flood Warning | PHI | New Castle | 3 hr |
| Jul 14, 3:10 PM EDT | Flash Flood Warning | PHI | Cecil | 2 hr |
| Jul 14, 3:18 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 12 min |
| Jul 14, 3:23 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 67 min |
| Jul 14, 3:24 PM EDT | Severe Thunderstorm Warning | LWX | Clarke, Fauquier, Loudoun, Prince William, Warren | 39 min |
| Jul 14, 3:34 PM EDT | Flash Flood Warning | PHI | New Castle | 3 hr |
| Jul 14, 3:35 PM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Cumberland, Gloucester | 55 min |
| Jul 14, 3:43 PM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Burlington, Camden, Gloucester, Salem | 47 min |
| Jul 14, 3:52 PM EDT | Flash Flood Warning | PHI | Talbot | 53 min |
| Jul 14, 3:54 PM EDT | Severe Thunderstorm Warning | PHI | Kent, New Castle | 66 min |
| Jul 14, 3:57 PM EDT | Flash Flood Warning | PHI | Cecil, Kent | 2 hr |
| Jul 14, 4:02 PM EDT | Severe Thunderstorm Warning | LWX | Albemarle, Augusta, Greene, Rockingham | 26 min |
| Jul 14, 4:12 PM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Cape May | 63 min |
| Jul 14, 4:13 PM EDT | Flash Flood Warning | PHI | Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more | 3 hr |
| Jul 14, 4:14 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 27 min |
| Jul 14, 4:24 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 51 min |
| Jul 14, 4:44 PM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Cape May, Cumberland, Gloucester, Salem | 61 min |
| Jul 14, 4:54 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 39 min |
| Jul 14, 4:59 PM EDT | Flash Flood Warning | PHI | Queen Anne's | 4 hr |
| Jul 14, 5:24 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 24 min |
| Jul 14, 5:40 PM EDT | Severe Thunderstorm Warning | PHI | Kent | 65 min |
| Jul 14, 5:54 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Talbot | 51 min |
| Jul 14, 5:58 PM EDT | Flash Flood Warning | PHI | Talbot | 3 hr |
| Jul 14, 6:10 PM EDT | Flash Flood Warning | PHI | Kent | 3 hr |
| Jul 14, 6:16 PM EDT | Severe Thunderstorm Warning | LWX | King George | 19 min |
| Jul 14, 6:20 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 40 min |
| Jul 14, 7:15 PM EDT | Severe Thunderstorm Warning | PHI | Sussex | 60 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, 5.7 hours before the alert went out and 62 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
- 403 J/kg
- Mixed-layer CIN
- -72 J/kg
- Mixed-layer LCL
- 1367 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 52 m²/s²
- 0-3 km storm-relative helicity
- 118 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 14, 1:09 PM EDT | Mesoscale Discussion | SPC | Kent, New Castle, Sussex | 2 hr |
| Jul 14, 4:23 PM EDT | Mesoscale Discussion | SPC | Kent, New Castle, Sussex | 67 min |
| Jul 14, 7:00 PM EDT | Mesoscale Discussion | SPC | Somerset, Wicomico, Worcester | 60 min |
Nearby
Severe Thunderstorm Watches in Virginia, 2017Severe Thunderstorm Watches in Maryland, 2017Severe Thunderstorm Watches in Pennsylvania, 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.