Alert archive / Tennessee / Mesoscale Discussions in 2017

Mesoscale Discussion 879

May 27, 201724 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at May 27, 2017, 7:02 PM CDT for 24 counties in Tennessee. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued
May 27, 2017, 7:02 PM CDT (00:02 UTC)
Expired
May 27, 2017, 8:00 PM CDT
In force
58 min
Issued by
the Storm Prediction Center
All 24 counties

Bedford County, TN, Cannon County, TN, Cheatham County, TN, Coffee County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, Moore County, TN, Robertson County, TN, Rutherford County, TN, Sumner County, TN, Warren County, TN, Williamson County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 73 km from the middle of the area, began a volume at 00:02 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

Nashville Metro, TN (KBNA), launched 00:00Z, 0.0 hours before the alert went out and 60 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 00:00Z on 2017-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2109 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 00:00Z on 2017-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 179 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
2109 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
841 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
179 m²/s²
0-3 km storm-relative helicity
175 m²/s²
Significant tornado parameter
2.0
Supercell composite
12.3

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
May 27, 9:07 PM CDTSevere Thunderstorm WatchSPCFranklin, Giles, Lawrence, Lincoln, Moore, Wayne8 hr
May 27, 9:26 PM CDTMesoscale DiscussionSPCFayette, Haywood, Lauderdale, Shelby, Tipton94 min
May 27, 9:46 PM CDTMesoscale DiscussionSPCAnderson, Bledsoe, Blount, Bradley, Carter, Claiborne and 24 more89 min
May 27, 9:59 PM CDTTornado WatchSPCChester, Crockett, Decatur, Fayette, Hardeman, Hardin and 7 more2 hr

Nearby

Mesoscale Discussions in Tennessee, 2017Every mesoscale discussion in 2017

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.