Alert archive / West Virginia / Mesoscale Discussions in 2021
Mesoscale Discussion 974
The Storm Prediction Center issued this mesoscale discussion at Jun 14, 2021, 7:37 PM EDT for Allegany County, Garrett County, Maryland; Frederick County, Shenandoah County, City of Winchester, Virginia; 20 counties in West Virginia. It was in force for 113 min.
The area
The outline as issued.
The facts
- Issued
- Jun 14, 2021, 7:37 PM EDT (23:37 UTC)
- Expired
- Jun 14, 2021, 9:30 PM EDT
- In force
- 113 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 271...272
All 25 counties
Allegany County, MD, Garrett County, MD, City of Winchester, VA, Frederick County, VA, Shenandoah County, VA, Barbour County, WV, Berkeley County, WV, Doddridge County, WV, Gilmer County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Harrison County, WV, Lewis County, WV, Marion County, WV, Mineral County, WV, Morgan County, WV, Pendleton County, WV, Preston County, WV, Randolph County, WV, Ritchie County, WV, Taylor County, WV, Tucker County, WV, Upshur County, WV, Wirt County, WV
The radar
The Pittsburgh radar (KPBZ), 163 km from the middle of the area, began a volume at 23:38 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.
The nearest sounding before it
Pittsburgh, PA (KPIT), launched 12:00Z, 11.6 hours before the alert went out and 147 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1684 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 26 m²/s²
- 0-3 km storm-relative helicity
- 72 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
418
ACUS11 KWNS 142338
SWOMCD
SPC MCD 142337
MDZ000-WVZ000-VAZ000-150130-
Mesoscale Discussion 0974
NWS Storm Prediction Center Norman OK
0637 PM CDT Mon Jun 14 2021
Areas affected...Northern West Virginia...western Maryland and far
northwest Virginia.
Concerning...Severe Thunderstorm Watch 271...272...
Valid 142337Z - 150130Z
The severe weather threat for Severe Thunderstorm Watch 271, 272
continues.
SUMMARY...The severe threat continues across WW 271 as well as WW
272. Damaging winds will continue to be the primary hazard, but a
few instances of severe hail remain possible. Given coming watch
expirations in the next 1-2 hours, local extensions may be needed
before storms exit the watch areas.
DISCUSSION...Several damaging wind reports, as well as a few
instances of quarter-sized hail, have been noted with a broken line
of storms across northern WV over the past 1-2 hours. Although these
storms have primarily been discrete to semi-discrete, regional
reflectivity and velocity data suggests that at least one or two
cells are beginning to develop organized outflows and take on more
linear characteristics. This is the expected evolution given storm
motion and deep-layer shear orientation to the initiating cold
front, and may support an increasing damaging wind threat in the
coming hours (though isolated severe hail will remain possible). One
mitigating factor is reduced instability immediately ahead of these
storms as they move across the higher terrain of northeast WV where
temperatures and dewpoints are cooler compared to surrounding
locations. However, re-intensification is possible as storms
transverse the terrain and move into a more unstable air mass across
northwest VA (see MCD 973 for details).
..Moore.. 06/14/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LWX...PBZ...RLX...
LAT...LON 39158144 39438056 39657966 39717896 39677797 39267789
38877830 38577863 38497925 38658006 38908095 39018155
39158144SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 14, 11:31 AM EDT | Mesoscale Discussion | SPC | Allegany, Garrett | 89 min |
| Jun 14, 3:55 PM EDT | Mesoscale Discussion | SPC | Allegany, Garrett, Washington | 65 min |
| Jun 14, 3:59 PM EDT | Severe Thunderstorm Watch | SPC | Allegany, Garrett, Washington | 6 hr |
| Jun 14, 6:41 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 13 more | 2 hr |
| Jun 14, 7:29 PM EDT | Severe Thunderstorm Watch | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 15 more | 6 hr |
| Jun 14, 11:46 AM EDT | Severe Thunderstorm Watch | SPC | Brooke, Hancock, Marion, Marshall, Monongalia, Ohio and 2 more | 6 hr |
| Jun 14, 3:25 PM EDT | Mesoscale Discussion | SPC | Brooke, Marshall, Ohio | 95 min |
| Jun 14, 4:52 PM EDT | Severe Thunderstorm Watch | SPC | Barbour, Doddridge, Harrison, Lewis, Marion, Marshall and 11 more | 6 hr |
Nearby
Mesoscale Discussions in West Virginia, 2021Mesoscale Discussions in Virginia, 2021Mesoscale Discussions in Maryland, 2021Every mesoscale discussion in 2021
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.