Alert archive / Ohio / Mesoscale Discussions in 2021
Mesoscale Discussion 1640
The Storm Prediction Center issued this mesoscale discussion at Aug 29, 2021, 1:07 PM EDT for 4 states. It was in force for 83 min.
The area
The outline as issued.
The facts
- Issued
- Aug 29, 2021, 1:07 PM EDT (17:07 UTC)
- Expired
- Aug 29, 2021, 2:30 PM EDT
- In force
- 83 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
All 73 counties
Allegany County, NY, Cattaraugus County, NY, Chautauqua County, NY, Erie County, NY, Genesee County, NY, Livingston County, NY, Monroe County, NY, Niagara County, NY, Orleans County, NY, Wyoming County, NY, Ashland County, OH, Ashtabula County, OH, Athens County, OH, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Cuyahoga County, OH, Fairfield County, OH, Geauga County, OH, Guernsey County, OH, Harrison County, OH, Hocking County, OH, Holmes 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, Portage 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, Cameron County, PA, Clarion County, PA, Clearfield County, PA, Crawford County, PA, Elk County, PA, Erie County, PA, Forest County, PA, Greene County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, McKean County, PA, Mercer County, PA, Venango County, PA, Warren County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Hancock County, WV, Marshall County, WV, Ohio County, WV, Pleasants County, WV, Tyler County, WV, Wetzel County, WV, Wood County, WV
The radar
The Pittsburgh radar (KPBZ), 94 km from the middle of the area, began a volume at 17:10 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, 5.1 hours before the alert went out and 108 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
- 985 J/kg
- Mixed-layer CIN
- -16 J/kg
- Mixed-layer LCL
- 957 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- 42 m²/s²
- 0-3 km storm-relative helicity
- 68 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
184
ACUS11 KWNS 291708
SWOMCD
SPC MCD 291707
NYZ000-PAZ000-WVZ000-OHZ000-291830-
Mesoscale Discussion 1640
NWS Storm Prediction Center Norman OK
1207 PM CDT Sun Aug 29 2021
Areas affected...Eastern Ohio...Western Pennsylvania...far Northern
West Virginia...and Western New York
Concerning...Severe potential...Watch unlikely
Valid 291707Z - 291830Z
Probability of Watch Issuance...5 percent
SUMMARY...A few localized damaging wind gusts may occur with the
strongest storms this afternoon.
DISCUSSION...Strong insolation and weak inhibition has led to rapid
destabilization and ensuing convective development across the
region. The warm/moist conditions near the surface, characterized by
temperatures in the mid to upper 80s F and dew point temperatures in
the low 70s F, are yielding approximately 1500-2000 J/kg of MLCAPE.
With continued heating through the afternoon amid a weakly sheared
environment, pulse-like storms can be expected to continue into the
early evening hours. Although organized convection is not expected,
somewhat moderate low-level lapse rates of 7-8 C/km should support
the threat for isolated damaging wind gusts with the strongest
cells. Watch issuance is not anticipated.
..Karstens/Grams.. 08/29/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BGM...BUF...CTP...PBZ...RLX...CLE...ILN...
LAT...LON 38928211 39348302 40508265 41548207 42447952 42787905
43117908 43527853 43587759 42567750 41017845 39688007
38928211Nearby
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.