Alert archive / Tennessee / Mesoscale Discussions in 2018

Mesoscale Discussion 932

June 28, 20184 states

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2018, 8:39 PM CDT for 4 states. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Jun 28, 2018, 8:39 PM CDT (01:39 UTC)
Expired
Jun 28, 2018, 10:15 PM CDT
In force
96 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 38 counties

Colbert County, AL, Lauderdale County, AL, Crittenden County, AR, Alcorn County, MS, Benton County, MS, DeSoto County, MS, Marshall County, MS, Prentiss County, MS, Tippah County, MS, Tishomingo County, MS, Benton County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Fayette County, TN, Giles County, TN, Hardeman County, TN, Hardin County, TN, Henderson County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Madison County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Perry County, TN, Robertson County, TN, Rutherford County, TN, Shelby County, TN, Wayne County, TN, Williamson County, TN

The radar

The Memphis radar (KNQA), 131 km from the middle of the area, began a volume at 01:40 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 00:00Z, 1.7 hours before the alert went out and 158 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 00:00Z on 2018-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2733 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, Little Rock, AR at 00:00Z on 2018-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -21 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
2733 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
1855 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-21 m²/s²
0-3 km storm-relative helicity
-8 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
Jun 28, 7:01 PM CDTMesoscale DiscussionSPCBaldwin, Choctaw, Clarke, Coffee, Conecuh, Covington and 6 more89 min
Jun 28, 11:00 PM CDTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Mississippi and 1 more90 min
Jun 28, 7:30 PM CDTMesoscale DiscussionSPCDyer, Gibson, Henry, Lake, Obion, Weakley90 min
Jun 28, 8:55 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Cheatham, Chester, Crockett, Decatur and 21 more4 hr

Nearby

Mesoscale Discussions in Tennessee, 2018Mesoscale Discussions in Mississippi, 2018Mesoscale Discussions in Alabama, 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.