Alert archive / Tennessee / Mesoscale Discussions in 2018

Mesoscale Discussion 907

June 27, 20185 states

The Storm Prediction Center issued this mesoscale discussion at Jun 27, 2018, 1:42 PM CDT for 5 states. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Jun 27, 2018, 1:42 PM CDT (18:42 UTC)
Expired
Jun 27, 2018, 3:15 PM CDT
In force
93 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 60 counties

Clay County, AR, Craighead County, AR, Crittenden County, AR, Greene County, AR, Lawrence County, AR, Mississippi County, AR, Poinsett County, AR, Randolph County, AR, Massac County, IL, Pulaski County, IL, Ballard County, KY, Calloway County, KY, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Trigg County, KY, Butler County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Scott County, MO, Stoddard County, MO, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dickson County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Giles County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lake County, TN, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Madison County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Obion County, TN, Perry County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Wayne County, TN, Weakley County, TN

The radar

The Paducah radar (KPAH), 112 km from the middle of the area, began a volume at 18:42 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, 6.7 hours before the alert went out and 204 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 2018-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 596 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 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 2018-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 358 square meters per square second.193958Sfc1 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
596 J/kg
Mixed-layer CIN
-52 J/kg
Mixed-layer LCL
603 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
358 m²/s²
0-3 km storm-relative helicity
420 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.3

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
Jun 26, 7:41 PM CDTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Independence and 6 more2 hr
Jun 26, 10:06 PM CDTMesoscale DiscussionSPCCrittenden, Cross84 min
Jun 27, 1:29 PM CDTMesoscale DiscussionSPCAllen, Barren, Clinton, Cumberland, Edmonson, Metcalfe and 3 more3 hr
Jun 26, 7:30 PM CDTMesoscale DiscussionSPCBarton, Bates, Cedar, Dade, Jasper, Lawrence and 2 more2 hr

Nearby

Mesoscale Discussions in Tennessee, 2018Mesoscale Discussions in Kentucky, 2018Mesoscale Discussions in Arkansas, 2018Every mesoscale discussion in 2018

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.