Alert archive / Kentucky / Mesoscale Discussions in 2021

Mesoscale Discussion 1451

August 9, 202138 counties in Kentucky

The Storm Prediction Center issued this mesoscale discussion at Aug 9, 2021, 12:50 PM CDT for 38 counties in Kentucky. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 9, 2021, 12:50 PM CDT (17:50 UTC)
Expired
Aug 9, 2021, 3:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%
All 38 counties

Adair County, KY, Barren County, KY, Bath County, KY, Breathitt County, KY, Casey County, KY, Clark County, KY, Clay County, KY, Clinton County, KY, Cumberland County, KY, Elliott County, KY, Estill County, KY, Fleming County, KY, Garrard County, KY, Jackson County, KY, Johnson County, KY, Knott County, KY, Knox County, KY, Laurel County, KY, Lee County, KY, Leslie County, KY, Lincoln County, KY, Madison County, KY, Magoffin County, KY, McCreary County, KY, Menifee County, KY, Metcalfe County, KY, Montgomery County, KY, Morgan County, KY, Owsley County, KY, Perry County, KY, Powell County, KY, Pulaski County, KY, Rockcastle County, KY, Rowan County, KY, Russell County, KY, Wayne County, KY, Whitley County, KY, Wolfe County, KY

The nearest sounding before it

Cncnati-Daytn, OH (KILN), launched 12:00Z, 5.8 hours before the alert went out and 226 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 12:00Z on 2021-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 210 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, Cncnati-Daytn, OH at 12:00Z on 2021-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.1939Sfc1 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
210 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
1127 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

428 
ACUS11 KWNS 091751
SWOMCD
SPC MCD 091750 
KYZ000-092015-

Mesoscale Discussion 1451
NWS Storm Prediction Center Norman OK
1250 PM CDT Mon Aug 09 2021

Areas affected...Portions of central/eastern KY

Concerning...Severe potential...Watch unlikely 

Valid 091750Z - 092015Z

Probability of Watch Issuance...5 percent

SUMMARY...An isolated strong/gusty wind threat should continue with
storms moving eastward this afternoon. Watch issuance is not
expected.

DISCUSSION...A loosely organized cluster of storms is moving
eastward across central KY this afternoon. Low-level flow in the
boundary layer quickly veers to westerly and modestly strengthens to
around 30 kt at mid levels per recent VWPs from KLVX. About
1000-2000 J/kg of MLCAPE and steepening low-level lapse rates with
continued daytime heating should allow for storms to persist into
eastern KY this afternoon. The lack of stronger mid-level flow will
likely limit overall storm organization and intensity. But,
strong/gusty outflow winds capable of producing mainly isolated tree
damage will be possible. Some signs of modestly enhanced outflow
winds have already been observed in recent velocity data from KLVX.
Regardless, the overall severe threat is expected to remain rather
isolated/marginal, and watch issuance is not expected.

..Gleason/Thompson.. 08/09/2021

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

ATTN...WFO...RLX...JKL...ILN...LMK...

LAT...LON   37138600 37228546 37498484 37938432 38238415 38438378
            38368324 38058277 37368279 36858325 36688444 36708525
            36848593 37138600

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.