Alert archive / Tennessee / Frost Advisories in 2018

Frost Advisory 8, NWS Memphis, TN

October 21, 201821 counties in Tennessee; 15 counties in Mississippi; 8 counties in Arkansas

NWS Memphis, TN issued this frost advisory at Oct 21, 2018, 3:22 AM CDT for 21 counties in Tennessee; 15 counties in Mississippi; 8 counties in Arkansas. It took effect at Oct 22, 2018, 3:00 AM CDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued: Oct 21, 2018, 3:22 AM CDT (08:22 UTC)
In effect from: Oct 22, 2018, 3:00 AM CDT
Expired: Oct 22, 2018, 8:59 AM CDT
In force: 6 hr
Issued by: NWS Memphis, TN

All 44 counties

Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Mississippi County, AR, Poinsett County, AR, St. Francis County, AR, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Pontotoc County, MS, Prentiss County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Benton County, TN, 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), 60 km from the middle of the area, began a volume at 08:25 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 00:00Z, 8.4 hours before the alert went out and 255 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1854 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 119 m²/s²
0-3 km storm-relative helicity: -9 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this frost advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Memphis, TN wrote its last area forecast discussion before this frost advisory went out at Oct 20, 6:34 PM CDT, 8 hours 48 minutes earlier.

Area forecast discussion, Oct 20, 6:34 PM CDT, 8 hours 48 minutes before

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Hazardous weather outlook, Oct 20, 3:40 AM CDT, 23 hours 42 minutes before

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The office that day

Everything else NWS Memphis, TN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 21, 2:46 PM CDT	Freeze Warning	MEG	Benton, Carroll, Decatur, Henderson, Henry	18 hr

Nearby

Frost Advisories in Tennessee, 2018 Frost Advisories in Mississippi, 2018 Frost Advisories in Arkansas, 2018 Every frost advisory 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.