Alert archive / Kentucky / Mesoscale Discussions in 2017

Mesoscale Discussion 579

April 28, 20174 states

The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2017, 4:59 PM CDT for 4 states. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Apr 28, 2017, 4:59 PM CDT (21:59 UTC)
Expired
Apr 28, 2017, 6:30 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 45 counties

Massac County, IL, Spencer County, IN, Adair County, KY, Allen County, KY, Ballard County, KY, Barren County, KY, Breckinridge County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Cumberland County, KY, Daviess County, KY, Edmonson County, KY, Graves County, KY, Grayson County, KY, Green County, KY, Hancock County, KY, Hardin County, KY, Hart County, KY, Hickman County, KY, Hopkins County, KY, Larue County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Marion County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Metcalfe County, KY, Monroe County, KY, Muhlenberg County, KY, Nelson County, KY, Ohio County, KY, Simpson County, KY, Taylor County, KY, Todd County, KY, Trigg County, KY, Warren County, KY, Washington County, KY, Webster County, KY, Mississippi County, MO

The radar

The Ft Campbell radar (KHPX), 55 km from the middle of the area, began a volume at 22:02 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

Little Rock, AR (KBYH), launched 12:00Z, 10.0 hours before the alert went out and 332 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, Little Rock, AR at 12:00Z on 2017-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Little Rock, AR at 12:00Z on 2017-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 370 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
750 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
370 m²/s²
0-3 km storm-relative helicity
528 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.

IssuedProductOfficeCountiesLasted
Apr 28, 1:10 PM CDTMesoscale DiscussionSPCAlexander, Bond, Clark, Clay, Clinton, Coles and 35 more2 hr
Apr 28, 6:28 PM CDTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more3 hr
Apr 28, 5:48 PM CDTMesoscale DiscussionSPCBartholomew, Boone, Brown, Clark, Clay, Daviess and 35 more117 min
Apr 28, 2:33 PM CDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bourbon, Boyle and 44 more87 min

Nearby

Mesoscale Discussions in Kentucky, 2017Mesoscale Discussions in Illinois, 2017Mesoscale Discussions in Indiana, 2017Every 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.