Alert archive / Tennessee / Mesoscale Discussions in 2017

Mesoscale Discussion 860

May 27, 201718 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at May 27, 2017, 7:49 AM CDT for 18 counties in Tennessee. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: May 27, 2017, 7:49 AM CDT (12:49 UTC)
Expired: May 27, 2017, 9:15 AM CDT
In force: 86 min
Issued by: the Storm Prediction Center

Counties Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Tipton County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 92 km from the middle of the area, began a volume at 12:50 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

Little Rock, AR (KBYH), launched 12:00Z, 0.8 hours before the alert went out and 130 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2792 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 535 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 68 m²/s²
0-3 km storm-relative helicity: 61 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 3.5

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.

Issued	Product	Office	Counties	Lasted
May 27, 3:54 AM CDT	Mesoscale Discussion	SPC	Dyer, Lake, Lauderdale, Obion	2 hr
May 27, 4:19 AM CDT	Severe Thunderstorm Watch	SPC	Benton, Carroll, Chester, Crockett, Decatur, Dyer and 15 more	6 hr
May 27, 6:12 AM CDT	Mesoscale Discussion	SPC	Benton, Carroll, Chester, Crockett, Decatur, Dyer and 15 more	2 hr
May 27, 9:13 AM CDT	Mesoscale Discussion	SPC	Anderson, Bedford, Benton, Bledsoe, Campbell, Cannon and 57 more	92 min
May 27, 12:50 PM CDT	Mesoscale Discussion	SPC	Anderson, Campbell, Claiborne, Clay, Fentress, Grainger and 9 more	85 min
May 27, 1:16 PM CDT	Mesoscale Discussion	SPC	Benton, Carroll, Crockett, Dyer, Gibson, Henry and 7 more	59 min
May 27, 1:36 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Carroll, Cheatham, Clay, Davidson, Dickson and 21 more	7 hr
May 27, 3:50 PM CDT	Mesoscale Discussion	SPC	Benton, Carroll, Cheatham, Clay, Davidson, Dickson and 19 more	85 min
May 27, 5:11 PM CDT	Mesoscale Discussion	SPC	Anderson, Blount, Campbell, Carter, Claiborne, Cocke and 16 more	64 min
May 27, 5:13 PM CDT	Severe Thunderstorm Watch PDS	SPC	Bedford, Benton, Cannon, Carroll, Cheatham, Clay and 40 more	7 hr
May 27, 5:55 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Bledsoe, Blount, Bradley, Campbell, Carter and 27 more	9 hr

Nearby

Mesoscale Discussions in Tennessee, 2017 Every 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.