Alert archive / Ohio / Mesoscale Discussions in 2024

Mesoscale Discussion 2021

August 27, 2024Chautauqua County, New York; 14 counties in Ohio; 5 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Aug 27, 2024, 8:39 PM EDT for Chautauqua County, New York; 14 counties in Ohio; 5 counties in Pennsylvania. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Aug 27, 2024, 8:39 PM EDT (00:39 UTC)
Expired
Aug 27, 2024, 10:15 PM EDT
In force
96 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 659

Counties Chautauqua County, NY, Ashland County, OH, Ashtabula County, OH, Crawford County, OH, Cuyahoga County, OH, Geauga County, OH, Huron County, OH, Lake County, OH, Mahoning County, OH, Medina County, OH, Portage County, OH, Richland County, OH, Summit County, OH, Trumbull County, OH, Wayne County, OH, Crawford County, PA, Erie County, PA, Mercer County, PA, Venango County, PA, Warren County, PA

The radar

The Cleveland radar (KCLE), 89 km from the middle of the area, began a volume at 00:38 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 00:00Z, 0.7 hours before the alert went out and 139 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.

Skew-T log-pSkew-T log-p diagram, Pittsburgh, PA at 00:00Z on 2024-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 340 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Pittsburgh, PA at 00:00Z on 2024-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
340 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
2030 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.7

Open this sounding in Storm Lab

The text

As transmitted.

691 
ACUS11 KWNS 280040
SWOMCD
SPC MCD 280039 
PAZ000-NYZ000-OHZ000-280215-

Mesoscale Discussion 2021
NWS Storm Prediction Center Norman OK
0739 PM CDT Tue Aug 27 2024

Areas affected...portions of far northern Ohio into extreme
northwestern Pennsylvania and extreme southwestern New York

Concerning...Severe Thunderstorm Watch 659...

Valid 280039Z - 280215Z

The severe weather threat for Severe Thunderstorm Watch 659
continues.

SUMMARY...Some severe threat will persist for a few more hours in
and immediately surrounding Severe Thunderstorm Watch 659. Damaging
gusts remain the primary concern.

DISCUSSION...A pronounced cold pool, originating from a mature
persistent elongated convective system, has surged southeastward
across Lake Erie over the past couple of hours. At least a few
severe gusts have been observed, and some convective rejuvenation
has occurred along the cold pool leading edge. Buoyancy
decreases/MLCINH increases with eastward and southward extent ahead
of the ongoing storms/cold pool. However, the fast pace of the cold
pool suggests that continued cellular regeneration and accompanying
damaging wind gust potential will continue for at least a couple
more hours.

..Squitieri.. 08/28/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...BUF...CTP...PBZ...CLE...

LAT...LON   40858328 41748140 42268059 42427980 42427919 42177908
            41847921 41387970 41068055 40838138 40638224 40858328

Nearby

Mesoscale Discussions in Ohio, 2024Mesoscale Discussions in Pennsylvania, 2024Mesoscale Discussions in New York, 2024Every mesoscale discussion in 2024

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.