Alert archive / Kentucky / Mesoscale Discussions in 2021

Mesoscale Discussion 843

June 3, 202147 counties in Kentucky; 35 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jun 3, 2021, 12:26 PM CDT for 47 counties in Kentucky; 35 counties in Tennessee. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 3, 2021, 12:26 PM CDT (17:26 UTC)
Expired
Jun 3, 2021, 2:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 82 counties

Adair County, KY, Allen County, KY, Anderson County, KY, Barren County, KY, Bourbon County, KY, Boyle County, KY, Bracken County, KY, Casey County, KY, Clark County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Fayette County, KY, Franklin County, KY, Garrard County, KY, Grant County, KY, Green County, KY, Harrison County, KY, Hart County, KY, Jessamine County, KY, Larue County, KY, Lincoln County, KY, Madison County, KY, Marion County, KY, Mason County, KY, McCreary County, KY, Mercer County, KY, Metcalfe County, KY, Monroe County, KY, Montgomery County, KY, Nelson County, KY, Nicholas County, KY, Owen County, KY, Pendleton County, KY, Pulaski County, KY, Robertson County, KY, Rockcastle County, KY, Russell County, KY, Scott County, KY, Shelby County, KY, Simpson County, KY, Spencer County, KY, Taylor County, KY, Warren County, KY, Washington County, KY, Wayne County, KY, Woodford County, KY, Bedford County, TN, Bledsoe County, TN, Cannon County, TN, Cheatham County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Grundy County, TN, Hickman County, TN, Jackson County, TN, Lewis County, TN, Macon County, TN, Marshall County, TN, Maury County, TN, Morgan County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Robertson County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, White County, TN, Williamson County, TN, Wilson County, TN

The radar

The Louisville radar (KLVX), 105 km from the middle of the area, began a volume at 17:28 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, 5.4 hours before the alert went out and 207 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, Nashville Metro, TN at 12:00Z on 2021-06-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 300 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, Nashville Metro, TN at 12:00Z on 2021-06-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 100 square meters per square second.19395878Sfc1 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
300 J/kg
Mixed-layer CIN
-68 J/kg
Mixed-layer LCL
837 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
100 m²/s²
0-3 km storm-relative helicity
129 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted.

580 
ACUS11 KWNS 031726
SWOMCD
SPC MCD 031726 
KYZ000-TNZ000-031930-

Mesoscale Discussion 0843
NWS Storm Prediction Center Norman OK
1226 PM CDT Thu Jun 03 2021

Areas affected...Central KY...Middle TN

Concerning...Severe potential...Watch unlikely 

Valid 031726Z - 031930Z

Probability of Watch Issuance...20 percent

SUMMARY...A few storms capable of damaging wind gusts and/or
isolated hail are possible for the next few hours.

DISCUSSION...Multiple southwest-to-northeast oriented thunderstorm
bands have developed from central KY into middle TN ahead of the
upper low currently centered near the convergence of MS and OH
Rivers. A belt of moderate southwesterly flow aloft precedes this
upper low, stretching from northwest MS through the TN Valley and
through the northern Mid-Atlantic. Overall instability is modest
(i.e. MLCAPE around 1000 J/kg per recent mesoanalysis), but still
sufficient for thunderstorm development. Some localized increases in
buoyancy are possible in areas where cloud breaks and resulting
stronger diurnal heating occurs. Given this combination of buoyancy
and moderate flow aloft, a few stronger storms capable of damaging
wind gusts and isolated hail may develop. Overall duration and
coverage of any strong to severe storms is expected to be limited,
owing predominately to the lack of stronger buoyancy.

..Mosier/Guyer.. 06/03/2021

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

ATTN...WFO...MRX...JKL...ILN...LMK...OHX...HUN...MEG...

LAT...LON   38258528 38778445 38698382 38458369 37558407 36328444
            35288540 35448821 38258528

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 2, 9:05 PM CDTMesoscale DiscussionSPCBenton, Cheatham, Davidson, Dickson, Hickman, Houston and 6 more85 min

Nearby

Mesoscale Discussions in Kentucky, 2021Mesoscale Discussions in Tennessee, 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.