Alert archive / Ohio / Mesoscale Discussions in 2017

Mesoscale Discussion 1620

September 4, 20175 states

The Storm Prediction Center issued this mesoscale discussion at Sep 4, 2017, 9:26 PM CDT for 5 states. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: Sep 4, 2017, 9:26 PM CDT (02:26 UTC)
Expired: Sep 4, 2017, 10:30 PM CDT
In force: 64 min
Issued by: the Storm Prediction Center

All 121 counties

Bond County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Jasper County, IL, Jefferson County, IL, Lawrence County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Perry County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Shelby County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, Adams County, IN, Bartholomew County, IN, Blackford County, IN, Boone County, IN, Brown County, IN, Clay County, IN, Clinton County, IN, Daviess County, IN, Decatur County, IN, Delaware County, IN, Fayette County, IN, Fountain County, IN, Franklin County, IN, Grant County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jay County, IN, Johnson County, IN, Knox County, IN, Madison County, IN, Marion County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Randolph County, IN, Rush County, IN, Shelby County, IN, Sullivan County, IN, Tipton County, IN, Union County, IN, Vermillion County, IN, Vigo County, IN, Wayne County, IN, Wells County, IN, City of Saint Louis, MO, Iron County, MO, Jefferson County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Washington County, MO, Allen County, OH, Ashland County, OH, Ashtabula County, OH, Auglaize County, OH, Butler County, OH, Champaign County, OH, Clark County, OH, Crawford County, OH, Cuyahoga County, OH, Darke County, OH, Delaware County, OH, Erie County, OH, Geauga County, OH, Greene County, OH, Hancock County, OH, Hardin County, OH, Holmes County, OH, Huron County, OH, Knox County, OH, Lake County, OH, Logan County, OH, Lorain County, OH, Madison County, OH, Marion County, OH, Medina County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Morrow County, OH, Ottawa County, OH, Paulding County, OH, Portage County, OH, Preble County, OH, Putnam County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Shelby County, OH, Stark County, OH, Summit County, OH, Trumbull County, OH, Union County, OH, Van Wert County, OH, Wayne County, OH, Wood County, OH, Wyandot County, OH, Erie County, PA

The radar

The Indianapolis radar (KIND), 45 km from the middle of the area, began a volume at 02:25 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

Lincoln, IL (KILX), launched 00:00Z, 2.4 hours before the alert went out and 181 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1325 J/kg
Mixed-layer CIN: -78 J/kg
Mixed-layer LCL: 909 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: -21 m²/s²
0-3 km storm-relative helicity: 132 m²/s²
Significant tornado parameter: -0.1
Supercell composite: -1.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 5, 1:31 PM CDT	Mesoscale Discussion	SPC	Adams, Cumberland, Dauphin, Franklin, Fulton, Juniata and 3 more	59 min
Sep 5, 2:26 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Berks, Bucks, Carbon, Chester, Cumberland and 13 more	5 hr
Sep 5, 4:00 PM CDT	Mesoscale Discussion	SPC	Berks, Bucks, Carbon, Chester, Delaware, Lancaster and 8 more	90 min

Nearby

Mesoscale Discussions in Ohio, 2017 Mesoscale Discussions in Indiana, 2017 Mesoscale Discussions in Illinois, 2017 Every mesoscale discussion in 2017

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.