Alert archive / Tennessee / Mesoscale Discussions in 2018

Mesoscale Discussion 1610

November 1, 20184 counties in Arkansas; 9 counties in Mississippi; 20 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Nov 1, 2018, 1:41 AM CDT for 4 counties in Arkansas; 9 counties in Mississippi; 20 counties in Tennessee. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Nov 1, 2018, 1:41 AM CDT (06:41 UTC)
Expired: Nov 1, 2018, 4:15 AM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

All 33 counties

Crittenden County, AR, Lee County, AR, Mississippi County, AR, St. Francis County, AR, Alcorn County, MS, Benton County, MS, DeSoto County, MS, Marshall County, MS, Prentiss County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 35 km from the middle of the area, began a volume at 06:40 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.

Tornado Watch 420Nov 1, 5:25 AM CDT

The nearest sounding before it

Little Rock, AR (KBYH), launched 00:00Z, 6.7 hours before the alert went out and 73 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: 381 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 535 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 220 m²/s²
0-3 km storm-relative helicity: 262 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.8

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
Oct 31, 8:14 PM CDT	Tornado Watch	SPC	Ashley, Chicot, Union	8 hr
Oct 31, 11:07 PM CDT	Tornado Watch	SPC	Phillips	9 hr
Oct 31, 11:52 PM CDT	Mesoscale Discussion	SPC	Ashley, Chicot, Columbia, Union	53 min
Nov 1, 1:19 AM CDT	Mesoscale Discussion	SPC	Chicot	116 min
Oct 31, 7:04 PM CDT	Mesoscale Discussion	SPC	Benton, Marshall	116 min
Oct 31, 10:01 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Attala, Calhoun, Carroll, Claiborne and 32 more	89 min
Nov 1, 4:30 AM CDT	Mesoscale Discussion	SPC	Attala, Calhoun, Chickasaw, Choctaw, Clarke, Clay and 33 more	2 hr

Nearby

Mesoscale Discussions in Tennessee, 2018 Mesoscale Discussions in Mississippi, 2018 Mesoscale Discussions in Arkansas, 2018 Every 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.