Alert archive / Tennessee / Areal Flood Advisories in 2021

Areal Flood Advisory 52, NWS Nashville, TN

July 18, 20214 counties in Tennessee

NWS Nashville, TN issued this areal flood advisory at Jul 18, 2021, 4:27 PM CDT for 4 counties in Tennessee. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued: Jul 18, 2021, 4:27 PM CDT (21:27 UTC)
Expired: Jul 18, 2021, 6:30 PM CDT
In force: 2 hr
Issued by: NWS Nashville, TN
Area: Storm-based polygon

Counties Davidson County, TN, Rutherford County, TN, Williamson County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 26 km from the middle of the area, began a volume at 21:28 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 12:00Z, 9.5 hours before the alert went out and 13 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: 949 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 588 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 0 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 areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Nashville, TN wrote its last area forecast discussion before this areal flood advisory went out at Jul 18, 3:22 PM CDT, 1 hour 5 minutes earlier.

Area forecast discussion, Jul 18, 3:22 PM CDT, 1 hour 5 minutes before

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Hazardous weather outlook, Jul 18, 5:08 AM CDT, 11 hours 19 minutes before

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In the hours before

Special weather statement, Jul 18, 3:54 PM CDT, 33 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 7:16 PM CDT	Areal Flood Advisory	OHX	Wilson	119 min
Jul 17, 7:38 PM CDT	Areal Flood Advisory	OHX	Lawrence	112 min
Jul 17, 8:00 PM CDT	Flash Flood Warning	OHX	Lawrence	3 hr
Jul 17, 8:40 PM CDT	Areal Flood Advisory	OHX	Lawrence, Wayne	3 hr
Jul 17, 9:03 PM CDT	Flash Flood Warning	OHX	Lawrence	117 min
Jul 17, 9:07 PM CDT	Areal Flood Advisory	OHX	Montgomery, Robertson, Sumner	113 min
Jul 17, 10:09 PM CDT	Areal Flood Advisory	OHX	Davidson, Sumner, Trousdale, Wilson	2 hr
Jul 17, 11:19 PM CDT	Areal Flood Advisory	OHX	Smith, Trousdale	116 min
Jul 18, 3:54 PM CDT	Special Weather Statement	OHX	Davidson	51 min
Jul 18, 4:03 PM CDT	Areal Flood Advisory	OHX	Davidson, Williamson	117 min
Jul 18, 4:31 PM CDT	Flash Flood Warning	OHX	Davidson	89 min
Jul 18, 4:42 PM CDT	Areal Flood Advisory	OHX	Cumberland	3 hr
Jul 18, 6:08 PM CDT	Areal Flood Advisory	OHX	Giles	112 min
Jul 18, 6:11 PM CDT	Areal Flood Advisory	OHX	DeKalb	2 hr
Jul 18, 6:14 PM CDT	Areal Flood Advisory	OHX	Sumner, Wilson	2 hr
Jul 18, 6:17 PM CDT	Areal Flood Advisory	OHX	Perry	118 min

Nearby

Areal Flood Advisories in Tennessee, 2021 Every areal flood advisory in 2021

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.