Alert archive / West Virginia / Mesoscale Discussions in 2021

Mesoscale Discussion 1900

October 25, 20214 counties in Kentucky; 22 counties in Ohio; 24 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Oct 25, 2021, 5:46 PM EDT for 4 counties in Kentucky; 22 counties in Ohio; 24 counties in West Virginia. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued: Oct 25, 2021, 5:46 PM EDT (21:46 UTC)
Expired: Oct 25, 2021, 7:45 PM EDT
In force: 119 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

All 50 counties

Boyd County, KY, Carter County, KY, Greenup County, KY, Lawrence County, KY, Athens County, OH, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Fairfield County, OH, Gallia County, OH, Guernsey County, OH, Harrison County, OH, Hocking County, OH, Jackson County, OH, Jefferson County, OH, Lawrence County, OH, Meigs County, OH, Monroe County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Tuscarawas County, OH, Vinton County, OH, Washington County, OH, Boone County, WV, Braxton County, WV, Brooke County, WV, Cabell County, WV, Calhoun County, WV, Clay County, WV, Doddridge County, WV, Gilmer County, WV, Hancock County, WV, Jackson County, WV, Kanawha County, WV, Lincoln County, WV, Marshall County, WV, Mason County, WV, Ohio County, WV, Pleasants County, WV, Putnam County, WV, Ritchie County, WV, Roane County, WV, Tyler County, WV, Wayne County, WV, Wetzel County, WV, Wirt County, WV, Wood County, WV

The radar

The Charleston,WV radar (KRLX), 101 km from the middle of the area, began a volume at 21:47 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.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 9.8 hours before the alert went out and 178 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1823 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 301 m²/s²
0-3 km storm-relative helicity: 281 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

998 
ACUS11 KWNS 252146
SWOMCD
SPC MCD 252146 
WVZ000-PAZ000-OHZ000-KYZ000-252345-

Mesoscale Discussion 1900
NWS Storm Prediction Center Norman OK
0446 PM CDT Mon Oct 25 2021

Areas affected...Portions of southeast Ohio...western West
Virginia...far southwest Pennsylvania

Concerning...Severe potential...Watch unlikely 

Valid 252146Z - 252345Z

Probability of Watch Issuance...20 percent

SUMMARY...A couple damaging gusts appear to be the primary threat
with the more intense storms embedded within a squall line. The
brief and localized nature of the severe threat suggests that a WW
issuance is unlikely.

DISCUSSION...A strongly forced convective line of low-topped
thunderstorms has recently developed over the past couple of hours
in southern OH/extreme northeast KY immediately ahead of a decaying
surface low/lee-trough axis. These storms are progressing into a
very marginally buoyant environment (MLCAPE slightly above 100
J/kg), driven primarily by a modestly heated surface airmass (mid
60s F temperatures and low to mid 50s F dewpoints). The 2118Z RLX
VWP depicts nearly 200 m2/s2 0-3km SRH, mainly due to veering within
the surface-1 km AGL layer. As such, the low-topped line of storms
is expected to remain somewhat organized as it crosses the warm
sector, with a couple damaging gusts the main concern and a brief
instance of transient rotation possible. The line is expected to
weaken shortly after sunset as the boundary layer stabilizes and the
line approaches western PA, where persistent cloud cover has
promoted a relatively more stable surface airmass.

..Squitieri/Hart.. 10/25/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...

LAT...LON   38258314 39978261 40638162 40848104 40728052 40598039
            40068035 39368048 38808057 38418071 38208108 37968148
            37878192 37938256 38258314

Nearby

Mesoscale Discussions in West Virginia, 2021 Mesoscale Discussions in Ohio, 2021 Mesoscale Discussions in Kentucky, 2021 Every 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.