Alert archive / Ohio / Mesoscale Discussions in 2021
Mesoscale Discussion 1474
The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2021, 9:31 AM EDT for 25 counties in Ohio; Lawrence County, Mercer County, Pennsylvania. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- Aug 11, 2021, 9:31 AM EDT (13:31 UTC)
- Expired
- Aug 11, 2021, 11:00 AM EDT
- In force
- 89 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
All 27 counties
Ashland County, OH, Ashtabula County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Crawford County, OH, Cuyahoga County, OH, Erie County, OH, Geauga County, OH, Harrison County, OH, Holmes County, OH, Huron County, OH, Knox County, OH, Lake County, OH, Lorain County, OH, Mahoning County, OH, Medina County, OH, Morrow County, OH, Portage County, OH, Richland County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Tuscarawas County, OH, Wayne County, OH, Lawrence County, PA, Mercer County, PA
The radar
The Cleveland radar (KCLE), 44 km from the middle of the area, began a volume at 13:32 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, 1.5 hours before the alert went out and 145 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
- 267 J/kg
- Mixed-layer CIN
- -243 J/kg
- Mixed-layer LCL
- 1321 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 131 m²/s²
- 0-3 km storm-relative helicity
- 188 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
910
ACUS11 KWNS 111332
SWOMCD
SPC MCD 111331
PAZ000-WVZ000-OHZ000-111500-
Mesoscale Discussion 1474
NWS Storm Prediction Center Norman OK
0831 AM CDT Wed Aug 11 2021
Areas affected...Northern Ohio into far northwest Pennsylvania
Concerning...Severe potential...Watch unlikely
Valid 111331Z - 111500Z
Probability of Watch Issuance...20 percent
SUMMARY...Isolated damaging wind gusts are possible through the
morning.
DISCUSSION...A cluster of storms is moving across northern Ohio and
has produced occasional stronger wind gusts including a gust to 41
kts at the Findlay, OH ASOS. Inbound velocities are showing stronger
wind speeds which based on this observation and lack of reports may
suggest winds are mostly below 50 knots. The downstream environment
is sufficiently unstable for MCS maintenance, but is not overly
favorable for a severe wind threat. Southward propagation toward the
better instability is likely through time and warming should lead to
significant destabilization by late morning to to early afternoon.
By this time, the severe weather threat may increase and a watch may
be needed. However, no watch is anticipated in the next 1 to 2 hours
given the current mostly weak downstream instability.
..Bentley/Thompson.. 08/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PBZ...CLE...
LAT...LON 41508263 41548186 41828116 41928080 41908065 41378019
41037999 40598050 40198112 40218167 40258241 40528303
40808333 41508263SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 10, 8:12 PM EDT | Mesoscale Discussion | SPC | Williams | 63 min |
| Aug 10, 8:38 PM EDT | Severe Thunderstorm Watch | SPC | Williams | 5 hr |
| Aug 10, 10:57 PM EDT | Mesoscale Discussion | SPC | Defiance, Fulton, Henry, Lucas, Paulding, Putnam and 2 more | 93 min |
| Aug 11, 10:52 AM EDT | Mesoscale Discussion | SPC | Defiance, Paulding, Williams | 83 min |
| Aug 11, 11:50 AM EDT | Mesoscale Discussion | SPC | Carroll, Columbiana, Harrison, Jefferson, Mahoning, Trumbull | 115 min |
| Aug 11, 11:50 AM EDT | Severe Thunderstorm Watch | SPC | Allen, Defiance, Fulton, Henry, Paulding, Putnam and 2 more | 4 hr |
| Aug 11, 1:26 PM EDT | Mesoscale Discussion | SPC | Allen, Defiance, Fulton, Henry, Paulding, Putnam and 2 more | 94 min |
| Aug 11, 2:12 PM EDT | Mesoscale Discussion | SPC | Allen, Ashland, Auglaize, Champaign, Crawford, Delaware and 26 more | 93 min |
| Aug 11, 2:32 PM EDT | Severe Thunderstorm Watch | SPC | Ashland, Auglaize, Champaign, Clark, Crawford, Cuyahoga and 28 more | 4 hr |
| Aug 11, 4:24 PM EDT | Mesoscale Discussion | SPC | Athens, Belmont, Carroll, Clinton, Columbiana, Coshocton and 31 more | 96 min |
| Aug 11, 4:57 PM EDT | Severe Thunderstorm Watch | SPC | Ashtabula, Belmont, Carroll, Columbiana, Coshocton, Geauga and 13 more | 3 hr |
| Aug 11, 2:03 PM EDT | Mesoscale Discussion | SPC | Adams, Armstrong, Bedford, Berks, Blair, Bucks and 42 more | 87 min |
| Aug 11, 3:02 PM EDT | Severe Thunderstorm Watch | SPC | Adams, Bedford, Berks, Blair, Bucks, Carbon and 26 more | 6 hr |
| Aug 11, 6:44 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Chester, Delaware, Lancaster and 6 more | 91 min |
Nearby
Mesoscale Discussions in Ohio, 2021Mesoscale Discussions in Pennsylvania, 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.