Alert archive / West Virginia / Severe Thunderstorm Watches in 2018
Severe Thunderstorm Watch 84
The Storm Prediction Center issued this severe thunderstorm watch at May 12, 2018, 2:47 PM EDT for 5 states. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- May 12, 2018, 2:47 PM EDT (18:47 UTC)
- Expired
- May 12, 2018, 10:47 PM EDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 76 counties
Allegany County, MD, Calvert County, MD, Charles County, MD, Frederick County, MD, Garrett County, MD, Montgomery County, MD, Prince George's County, MD, Saint Mary's County, MD, Washington County, MD, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Guernsey County, OH, Harrison County, OH, Jefferson County, OH, Monroe County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Tuscarawas County, OH, Washington County, OH, Adams County, PA, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Bedford County, PA, Blair County, PA, Butler County, PA, Cambria County, PA, Cumberland County, PA, Fayette County, PA, Franklin County, PA, Fulton County, PA, Greene County, PA, Huntingdon County, PA, Indiana County, PA, Juniata County, PA, Mifflin County, PA, Perry County, PA, Somerset County, PA, Washington County, PA, Westmoreland County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Winchester, VA, Clarke County, VA, Fairfax County, VA, Frederick County, VA, Loudoun County, VA, Barbour County, WV, Berkeley County, WV, Brooke County, WV, Doddridge County, WV, Grant County, WV, Hampshire County, WV, Hancock County, WV, Hardy County, WV, Harrison County, WV, Jefferson County, WV, Marion County, WV, Marshall County, WV, Mineral County, WV, Monongalia County, WV, Morgan County, WV, Ohio County, WV, Pleasants County, WV, Preston County, WV, Ritchie County, WV, Taylor County, WV, Tucker County, WV, Tyler County, WV, Wetzel County, WV, Wood County, WV
The radar
The Pittsburgh radar (KPBZ), 71 km from the middle of the area, began a volume at 18:47 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
- 60%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
19 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 12, 3:23 PM EDT | Severe Thunderstorm Warning | CTP | Bedford, Blair, Cambria, Somerset | 67 min |
| May 12, 3:27 PM EDT | Severe Thunderstorm Warning | PBZ | Harrison, Jefferson | 33 min |
| May 12, 3:29 PM EDT | Severe Thunderstorm Warning | PBZ | Allegheny, Armstrong, Indiana, Westmoreland | 46 min |
| May 12, 3:48 PM EDT | Severe Thunderstorm Warning | PBZ | Belmont, Guernsey | 42 min |
| May 12, 3:54 PM EDT | Severe Thunderstorm Warning | PBZ | Belmont, Jefferson | 51 min |
| May 12, 4:12 PM EDT | Severe Thunderstorm Warning | CTP | Bedford, Franklin, Fulton, Huntingdon | 63 min |
| May 12, 4:13 PM EDT | Severe Thunderstorm Warning | PBZ | Indiana, Westmoreland | 32 min |
| May 12, 4:16 PM EDT | Severe Thunderstorm Warning | PBZ | Fayette, Westmoreland | 59 min |
| May 12, 4:19 PM EDT | Severe Thunderstorm Warning | CTP | Bedford, Blair, Cambria, Somerset | 56 min |
| May 12, 4:37 PM EDT | Severe Thunderstorm Warning | PBZ | Fayette, Westmoreland | 38 min |
| May 12, 4:53 PM EDT | Severe Thunderstorm Warning | RLX | Morgan, Perry | 12 min |
| May 12, 5:30 PM EDT | Severe Thunderstorm Warning | PBZ | Allegheny, Fayette, Greene, Washington, Westmoreland | 45 min |
| May 12, 6:21 PM EDT | Severe Thunderstorm Warning | CTP | Bedford, Cambria, Somerset | 39 min |
| May 12, 6:52 PM EDT | Severe Thunderstorm Warning | CTP | Adams, York | 53 min |
| May 12, 6:55 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Harford | 65 min |
| May 12, 7:46 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 22 min |
| May 12, 8:13 PM EDT | Flash Flood Warning | PBZ | Westmoreland | 108 min |
| May 12, 8:28 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 62 min |
| May 12, 8:47 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Prince George's, Saint Mary's | 88 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
Pittsburgh, PA (KAGC), launched 12:00Z, 6.8 hours before the alert went out and 55 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
- 1 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1381 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 312 m²/s²
- 0-3 km storm-relative helicity
- 354 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 |
|---|---|---|---|---|
| May 12, 1:51 PM EDT | Mesoscale Discussion | SPC | Allegany, Garrett | 2 hr |
| May 12, 3:59 PM EDT | Mesoscale Discussion | SPC | Baltimore, Carroll, Cecil, Harford, Howard, Kent and 3 more | 3 hr |
| May 12, 4:58 PM EDT | Tornado Watch | SPC | Anne Arundel, Baltimore, Caroline, Carroll, Cecil, Harford and 5 more | 5 hr |
| May 12, 5:05 PM EDT | Mesoscale Discussion | SPC | Allegany, Frederick, Garrett, Washington | 115 min |
| May 12, 7:16 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Caroline, Carroll, Cecil, Harford and 5 more | 59 min |
| May 12, 4:20 PM EDT | Mesoscale Discussion | SPC | Butler, Champaign, Clark, Clinton, Darke, Fairfield and 12 more | 115 min |
Nearby
Severe Thunderstorm Watches in West Virginia, 2018Severe Thunderstorm Watches in Pennsylvania, 2018Severe Thunderstorm Watches in Ohio, 2018Every severe thunderstorm watch in 2018
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.