Alert archive / Ohio / Mesoscale Discussions in 2021
Mesoscale Discussion 1197
The Storm Prediction Center issued this mesoscale discussion at Jul 8, 2021, 1:31 PM EDT for 4 counties in New York; 17 counties in Ohio; 6 counties in Pennsylvania. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 8, 2021, 1:31 PM EDT (17:31 UTC)
- Expired
- Jul 8, 2021, 4:00 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
All 27 counties
Cattaraugus County, NY, Chautauqua County, NY, Erie County, NY, Wyoming County, NY, Ashland County, OH, Ashtabula County, OH, Carroll County, OH, Columbiana County, OH, Cuyahoga County, OH, Geauga County, OH, Holmes County, OH, Lake County, OH, Mahoning County, OH, Medina County, OH, Morrow County, OH, Portage County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Tuscarawas County, OH, Wayne County, OH, Crawford County, PA, Erie County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA, Warren County, PA
The radar
The Cleveland radar (KCLE), 124 km from the middle of the area, began a volume at 17:35 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, 5.5 hours before the alert went out and 144 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
- 174 J/kg
- Mixed-layer CIN
- -40 J/kg
- Mixed-layer LCL
- 757 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 132 m²/s²
- 0-3 km storm-relative helicity
- 107 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
The text
As transmitted.
190
ACUS11 KWNS 081732
SWOMCD
SPC MCD 081731
NYZ000-PAZ000-OHZ000-082000-
Mesoscale Discussion 1197
NWS Storm Prediction Center Norman OK
1231 PM CDT Thu Jul 08 2021
Areas affected...northeast Ohio into western New York
Concerning...Severe potential...Watch unlikely
Valid 081731Z - 082000Z
Probability of Watch Issuance...20 percent
SUMMARY...A few severe storms are possible as activity strengthens
across northeast Ohio and moves into western Pennsylvania and New
York.
DISCUSSION...Storms continue to increase near surface trough in OH,
where pockets of heating have led to a plume of 1500 J/kg MLCAPE.
While currently cooler downstream into PA and NY, slightly backed
low-level winds have led to around 100 m2/s2 0-1 SRH. This area is
near the upper wave axis, and further destabilization is possible
into PA and NY due to warm advection from the southwest.
Hodographs are not overly large, but indicative of a marginal
supercell environment with around 30 kt effective shear and
aforementioned low-level SRH. While storms are currently oriented
along a line in OH, a good cross-boundary component may support
individual cells with the line.
..Jewell/Guyer.. 07/08/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BUF...CTP...PBZ...CLE...
LAT...LON 40458296 40788251 41168227 41508210 41948102 42278002
42577948 42927907 43017855 42877822 42687802 42287813
41777905 40988016 40498104 40438153 40458296SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 8, 12:00 AM EDT | Mesoscale Discussion | SPC | Albany, Columbia, Dutchess, Greene, Orange, Putnam and 6 more | 60 min |
| Jul 8, 1:44 PM EDT | Mesoscale Discussion | SPC | Bronx, Kings, Nassau, New York, Orange, Putnam and 4 more | 3 hr |
| Jul 8, 2:09 PM EDT | Severe Thunderstorm Watch | SPC | Bronx, Dutchess, Kings, Nassau, New York, Orange and 7 more | 7 hr |
| Jul 8, 4:36 PM EDT | Mesoscale Discussion | SPC | Bronx, Kings, Nassau, New York, Orange, Putnam and 5 more | 114 min |
| Jul 8, 1:51 PM EDT | Mesoscale Discussion | SPC | Butler, Hamilton | 84 min |
Nearby
Mesoscale Discussions in Ohio, 2021Mesoscale Discussions in Pennsylvania, 2021Mesoscale Discussions in New York, 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.