Alert archive / Ohio / Mesoscale Discussions in 2017
Mesoscale Discussion 928
The Storm Prediction Center issued this mesoscale discussion at May 31, 2017, 2:05 PM EDT for 37 counties in Ohio; 13 counties in Pennsylvania; 12 counties in West Virginia. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- May 31, 2017, 2:05 PM EDT (18:05 UTC)
- Expired
- May 31, 2017, 3:30 PM EDT
- In force
- 85 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 62 counties
Ashland County, OH, Ashtabula County, OH, Athens County, OH, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Fairfield County, OH, Gallia County, OH, Geauga County, OH, Guernsey County, OH, Harrison County, OH, Hocking County, OH, Holmes County, OH, Jackson County, OH, Jefferson County, OH, Knox County, OH, Lake County, OH, Licking County, OH, Mahoning County, OH, Medina County, OH, Meigs County, OH, Monroe County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Pike County, OH, Portage County, OH, Ross County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Tuscarawas County, OH, Vinton County, OH, Washington County, OH, Wayne County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Crawford County, PA, Forest County, PA, Greene County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA, Warren County, PA, Washington County, PA, Brooke County, WV, Doddridge County, WV, Hancock County, WV, Marshall County, WV, Mason County, WV, Ohio County, WV, Pleasants County, WV, Ritchie County, WV, Tyler County, WV, Wetzel County, WV, Wirt County, WV, Wood County, WV
The radar
The Pittsburgh radar (KPBZ), 70 km from the middle of the area, began a volume at 18:08 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 (KAGC), launched 12:00Z, 6.1 hours before the alert went out and 84 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
- 2 J/kg
- Mixed-layer CIN
- -112 J/kg
- Mixed-layer LCL
- 1946 m above ground
- 0-6 km bulk shear
- 64 kt
- 0-1 km storm-relative helicity
- 121 m²/s²
- 0-3 km storm-relative helicity
- 177 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
267
ACUS11 KWNS 311805
SWOMCD
SPC MCD 311805
PAZ000-NYZ000-WVZ000-OHZ000-311930-
Mesoscale Discussion 0928
NWS Storm Prediction Center Norman OK
0105 PM CDT Wed May 31 2017
Areas affected...Eastern OH...Western PA...Northern WV
Concerning...Severe potential...Watch unlikely
Valid 311805Z - 311930Z
Probability of Watch Issuance...20 percent
SUMMARY...Isolated hail and damaging wind gusts are possible over
the next several hours as thunderstorms move across eastern OH,
western PA, and far northern WV.
DISCUSSION...Storms have developed over the past hour within the
modestly unstable airmass across central OH. Primary forcing for
this increased convection is likely the shortwave trough currently
pivoting through the southwestern periphery of the large upper low
centered over Ontario. Despite relatively scant low-level moisture,
some instability has developed ahead of these storms across central
OH and western PA, largely as a result of cool mid-level
temperatures (around -19 deg C at 500 mb) and modest surface
heating. Unidirectional shear profiles will support fast storm
motion and the potential for a few strong wind gusts with the more
robust updrafts. Additionally, the enhanced flow aloft and resulting
potential updraft organization is supportive of an isolated hail
threat. Limited severe coverage is currently expected, precluding
higher watch probabilities. Even so, convective trends across the
area will be monitored closely.
..Mosier/Hart.. 05/31/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BUF...CTP...PBZ...RLX...CLE...ILN...
LAT...LON 40228276 41128209 41778124 42068055 42078007 41997953
41847924 41387914 39997973 39238056 38708213 38988324
40228276SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 31, 12:29 PM EDT | Mesoscale Discussion | SPC | Lackawanna, Susquehanna, Wayne, Wyoming | 61 min |
| May 31, 7:34 PM EDT | Mesoscale Discussion | SPC | Susquehanna, Wayne | 86 min |
Nearby
Mesoscale Discussions in Ohio, 2017Mesoscale Discussions in Pennsylvania, 2017Mesoscale Discussions in West Virginia, 2017Every mesoscale discussion 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.