Alert archive / Ohio / Mesoscale Discussions in 2021
Mesoscale Discussion 1486
The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2021, 4:24 PM EDT for 37 counties in Ohio. It was in force for 96 min.
The area
The outline as issued.
The facts
- Issued
- Aug 11, 2021, 4:24 PM EDT (20:24 UTC)
- Expired
- Aug 11, 2021, 6:00 PM EDT
- In force
- 96 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 60%
All 37 counties
Athens County, OH, Belmont County, OH, Carroll County, OH, Clinton County, OH, Columbiana County, OH, Coshocton County, OH, Fairfield County, OH, Fayette County, OH, Franklin County, OH, Geauga County, OH, Greene County, OH, Guernsey County, OH, Harrison County, OH, Highland County, OH, Hocking County, OH, Holmes County, OH, Jackson County, OH, Jefferson County, OH, Licking County, OH, Mahoning County, OH, Meigs County, OH, Morgan County, OH, Muskingum County, OH, Noble County, OH, Perry County, OH, Pickaway 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, Warren County, OH, Washington County, OH, Wayne County, OH
The radar
The Cincinnati radar (KILN), 151 km from the middle of the area, began a volume at 20:27 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Cncnati-Daytn, OH (KILN), launched 12:00Z, 8.4 hours before the alert went out and 149 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
- 1853 J/kg
- Mixed-layer CIN
- -70 J/kg
- Mixed-layer LCL
- 1037 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- 46 m²/s²
- 0-3 km storm-relative helicity
- 71 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
652
ACUS11 KWNS 112024
SWOMCD
SPC MCD 112024
OHZ000-112200-
Mesoscale Discussion 1486
NWS Storm Prediction Center Norman OK
0324 PM CDT Wed Aug 11 2021
Areas affected...Southern and Eastern Ohio
Concerning...Severe potential...Watch possible
Valid 112024Z - 112200Z
Probability of Watch Issuance...60 percent
SUMMARY...Portions of eastern and southern Ohio are being monitored
for a potential watch downstream of watch 426.
DISCUSSION...A line of storms continues east across northern Ohio.
The airmass remains unstable downstream of this activity within
watch 426 but then becomes more uncertain to its south and east. A
large area of outflow from storms in West Virginia this morning has
surged northward and stabilized portions of southern and eastern
Ohio as can be observed by the lack of cu on visible satellite. In
addition, storms developed on this boundary in far eastern Ohio
which has acted to reinforce this outflow boundary as it continues
north. This may limit convective intensity across portions of
southeast and eastern Ohio. However, west of this outflow boundary,
a very unstable airmass is in place with MLCAPE around 3000 J/kg.
Recently storms have started to form ahead of the line within the
cumulus field which could also could pose some severe risk given the
instability.
..Bentley/Thompson.. 08/11/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PBZ...RLX...CLE...ILN...
LAT...LON 39058196 38918232 39148379 39598453 39778375 40158262
41208167 41838084 41938054 40008074 39188180 39058196SPC 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, 9:31 AM EDT | Mesoscale Discussion | SPC | Ashland, Ashtabula, Carroll, Columbiana, Coshocton, Crawford and 19 more | 89 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, 4:57 PM EDT | Severe Thunderstorm Watch | SPC | Ashtabula, Belmont, Carroll, Columbiana, Coshocton, Geauga and 13 more | 3 hr |
Nearby
Mesoscale Discussions in Ohio, 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.