Alert archive / Kentucky / Mesoscale Discussions in 2020

Mesoscale Discussion 818

June 4, 20204 states

The Storm Prediction Center issued this mesoscale discussion at Jun 4, 2020, 2:42 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 4, 2020, 2:42 PM CDT (19:42 UTC)
Expired: Jun 4, 2020, 4:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 5%

All 59 counties

Alexander County, IL, Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Johnson County, IL, Lawrence County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Richland County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Crawford County, IN, Daviess County, IN, Dubois County, IN, Floyd County, IN, Gibson County, IN, Greene County, IN, Harrison County, IN, Knox County, IN, Lawrence County, IN, Martin County, IN, Orange County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Washington County, IN, Ballard County, KY, Breckinridge County, KY, Caldwell County, KY, Carlisle County, KY, Crittenden County, KY, Daviess County, KY, Graves County, KY, Hancock County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Meade County, KY, Muhlenberg County, KY, Ohio County, KY, Union County, KY, Webster County, KY, Mississippi County, MO, Scott County, MO

The radar

The Evansville,IN radar (KVWX), 56 km from the middle of the area, began a volume at 19:45 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

Nashville Metro, TN (KBNA), launched 12:00Z, 7.7 hours before the alert went out and 225 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: 188 J/kg
Mixed-layer CIN: -71 J/kg
Mixed-layer LCL: 849 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 73 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Jun 4, 5:14 PM CDT	Mesoscale Discussion	SPC	Rock Island	91 min
Jun 4, 10:11 AM CDT	Mesoscale Discussion	SPC	Bartholomew, Brown, Clark, Crawford, Daviess, Dearborn and 34 more	2 hr
Jun 3, 8:54 PM CDT	Mesoscale Discussion	SPC	Atchison, Holt	2 hr
Jun 3, 9:38 PM CDT	Severe Thunderstorm Watch	SPC	Andrew, Atchison, Buchanan, Clay, Clinton, Holt and 3 more	6 hr
Jun 3, 10:44 PM CDT	Mesoscale Discussion	SPC	Andrew, Atchison, Bates, Buchanan, Caldwell, Cass and 11 more	2 hr
Jun 4, 12:54 AM CDT	Mesoscale Discussion	SPC	Andrew, Barton, Bates, Buchanan, Caldwell, Cass and 16 more	96 min
Jun 4, 2:07 AM CDT	Severe Thunderstorm Watch	SPC	Barton, Bates, Cass, Cedar, Dade, Greene and 7 more	5 hr
Jun 4, 3:32 AM CDT	Mesoscale Discussion	SPC	Barton, Bates, Benton, Cedar, Dade, Greene and 6 more	88 min
Jun 4, 5:44 AM CDT	Mesoscale Discussion	SPC	Barry, Christian, Stone, Taney	61 min

Nearby

Mesoscale Discussions in Kentucky, 2020 Mesoscale Discussions in Illinois, 2020 Mesoscale Discussions in Indiana, 2020 Every mesoscale discussion in 2020

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.