Alert archive / Kentucky / Mesoscale Discussions in 2021

Mesoscale Discussion 2014

December 11, 202110 counties in Kentucky

The Storm Prediction Center issued this mesoscale discussion at Dec 11, 2021, 3:51 AM EST for 10 counties in Kentucky. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued
Dec 11, 2021, 3:51 AM EST (08:51 UTC)
Expired
Dec 11, 2021, 4:45 AM EST
In force
54 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 561

Counties Boyle County, KY, Casey County, KY, Clark County, KY, Estill County, KY, Garrard County, KY, Jessamine County, KY, Lincoln County, KY, Madison County, KY, Mercer County, KY, Montgomery County, KY

The radar

The Jackson,KY radar (KJKL), 109 km from the middle of the area, began a volume at 08:51 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

Cncnati-Daytn, OH (KILN), launched 00:00Z, 8.9 hours before the alert went out and 203 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, Cncnati-Daytn, OH at 00:00Z on 2021-12-11Temperature 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, Cncnati-Daytn, OH at 00:00Z on 2021-12-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 325 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
519 m above ground
0-6 km bulk shear
71 kt
0-1 km storm-relative helicity
325 m²/s²
0-3 km storm-relative helicity
431 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

505 
ACUS11 KWNS 110851
SWOMCD
SPC MCD 110851 
KYZ000-110945-

Mesoscale Discussion 2014
NWS Storm Prediction Center Norman OK
0251 AM CST Sat Dec 11 2021

Areas affected...portions of east-central KY

Concerning...Tornado Watch 561...

Valid 110851Z - 110945Z

The severe weather threat for Tornado Watch 561 continues.

SUMMARY...Damaging wind gusts and a tornado or two remain possible
across WW 561.

DISCUSSION...A supercell over Marion County Kentucky has shown
periods of strong rotation with a tornado debris signature noted
over the past 15-30 minutes. Rotation associated with this storm has
recently weakened as it continues northeast into eastern portions of
the Louisville CWA. This is likely due to weaker low-level
instability as surface dewpoints drop off rather quickly from the
mid 60s to upper 50s/low 60s. While the cluster of storms over
central KY may still produce strong, damaging gusts, the narrowing
warm sector downstream may begin to limit stronger tornado potential
over the next 1-2 hours.

..Leitman.. 12/11/2021

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

ATTN...WFO...JKL...LMK...

LAT...LON   37758512 37978464 38088434 38128406 38038388 37898380
            37748387 37568399 37418441 37318484 37328503 37358519
            37478526 37758512

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 10, 7:21 PM ESTTornado WatchSPCAllen, Anderson, Barren, Breckinridge, Bullitt, Butler and 28 more10 hr
Dec 10, 7:22 PM ESTMesoscale DiscussionSPCFulton, Graves, Hickman53 min
Dec 10, 8:41 PM ESTMesoscale DiscussionSPCFulton64 min
Dec 10, 9:35 PM ESTMesoscale DiscussionSPCAllen, Barren, Breckinridge, Bullitt, Butler, Caldwell and 26 more85 min
Dec 10, 9:48 PM ESTMesoscale DiscussionSPCCarlisle, Fulton, Graves, Hickman, Lyon, Marshall57 min
Dec 10, 10:48 PM ESTMesoscale DiscussionSPCCaldwell, Graves, Hopkins, Lyon, Marshall57 min
Dec 10, 11:09 PM ESTMesoscale DiscussionSPCBallard, Caldwell, Calloway, Carlisle, Crittenden, Fulton and 7 more96 min
Dec 10, 11:44 PM ESTMesoscale DiscussionSPCCaldwell, Grayson, Hopkins, McLean, Muhlenberg, Ohio61 min
Dec 11, 12:03 AM ESTTornado WatchSPCBallard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 16 more5 hr
Dec 11, 12:08 AM ESTMesoscale DiscussionSPCBoone, Bracken, Campbell, Carroll, Gallatin, Grant and 8 more67 min
Dec 11, 12:20 AM ESTTornado WatchSPCBoone, Bracken, Campbell, Carroll, Gallatin, Grant and 6 more6 hr
Dec 11, 12:28 AM ESTMesoscale DiscussionSPCUnion92 min
Dec 11, 12:36 AM ESTMesoscale DiscussionSPCCalloway, Christian, Logan, Simpson, Todd, Trigg54 min
Dec 11, 12:53 AM ESTMesoscale DiscussionSPCBreckinridge, Bullitt, Grayson, Hardin, Jefferson, Meade and 3 more67 min
Dec 11, 2:02 AM ESTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 51 more88 min
Dec 11, 2:05 AM ESTMesoscale DiscussionSPCBarren, Butler, Edmonson, Green, Hart, Logan and 2 more55 min
Dec 11, 2:27 AM ESTTornado WatchSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 51 more7 hr
Dec 11, 6:32 AM ESTMesoscale DiscussionSPCBell, Breathitt, Clark, Clay, Estill, Jackson and 18 more88 min

Nearby

Mesoscale Discussions in Kentucky, 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.