Alert archive / Tennessee / Areal Flood Advisories in 2021

Areal Flood Advisory 101, NWS Nashville, TN

August 21, 20214 counties in Tennessee

NWS Nashville, TN issued this areal flood advisory at Aug 21, 2021, 4:10 AM CDT for 4 counties in Tennessee. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Aug 21, 2021, 4:10 AM CDT (09:10 UTC)
Expired: Aug 21, 2021, 7:15 AM CDT
In force: 3 hr
Issued by: NWS Nashville, TN
Area: Storm-based polygon

Counties Giles County, TN, Lawrence County, TN, Lewis County, TN, Maury County, TN

The radar

The Nashville radar (KOHX), 114 km from the middle of the area, began a volume at 09:14 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 (KLZK), launched 00:00Z, 9.2 hours before the alert went out and 253 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: 1267 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 1206 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 49 m²/s²
0-3 km storm-relative helicity: 104 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 Aug 21, 2:22 AM CDT, 1 hour 48 minutes earlier.

Area forecast discussion, Aug 21, 2:22 AM CDT, 1 hour 48 minutes before

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Hazardous weather outlook, Aug 21, 2:55 AM CDT, 1 hour 15 minutes before

Hazardous Weather Outlook
National Weather Service Nashville TN
255 AM CDT Sat Aug 21 2021

TNZ005>011-023>034-056>066-075-077>080-093>095-221030-
Stewart-Montgomery-Robertson-Sumner-Macon-Clay-Pickett-Houston-
Humphreys-Dickson-Cheatham-Davidson-Wilson-Trousdale-Smith-Jackson-
Putnam-Overton-Fentress-Perry-Hickman-Lewis-Williamson-Maury-
Marshall-Rutherford-Cannon-De Kalb-White-Cumberland-Bedford-Coffee-
Warren-Grundy-Van Buren-Wayne-Lawrence-Giles-
255 AM CDT Sat Aug 21 2021

This Hazardous Weather Outlook is for Middle Tennessee.

.DAY ONE...Today and tonight.

A Flash Flood Watch is in effect through 3 PM today for areas around
and west of I-24. Heavy rain from showers and thunderstorms will
combine with already saturated soils for an increased risk of flash
into this afternoon.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed. Please relay any information about
observed severe weather to the NWS while following all local, state,
and CDC guidelines.

07

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 2:48 AM CDT	Areal Flood Advisory	OHX	Dickson, Hickman, Humphreys, Lewis	2 hr
Aug 21, 3:29 AM CDT	Flash Flood Warning	OHX	Dickson, Hickman, Humphreys	5 hr
Aug 21, 4:29 AM CDT	Areal Flood Advisory	OHX	Montgomery, Stewart	3 hr
Aug 21, 4:49 AM CDT	Flash Flood Warning	OHX	Dickson, Hickman, Houston, Humphreys	3 hr
Aug 21, 6:24 AM CDT	Flash Flood Warning	OHX	Houston, Humphreys, Stewart	5 hr
Aug 21, 7:47 AM CDT	Flash Flood Warning EmergencyCatastrophic damage threat	OHX	Dickson, Hickman, Houston, Humphreys	9 hr
Aug 21, 8:39 AM CDT	River Flood Warning	OHX	Hickman	13 hr
Aug 21, 9:41 AM CDT	Areal Flood Advisory	OHX	Hickman, Lewis, Maury	3 hr
Aug 21, 10:12 AM CDT	Flash Flood Warning	OHX	Hickman, Humphreys, Lewis, Maury, Perry	3 hr
Aug 21, 10:17 AM CDT	River Flood Advisory	OHX	Hickman	52 hr
Aug 21, 11:39 AM CDT	Areal Flood Advisory	OHX	Giles, Lawrence, Marshall	3 hr
Aug 21, 12:33 PM CDT	River Flood Warning	OHX	Humphreys	44 hr
Aug 21, 4:40 PM CDT	Areal Flood Advisory	OHX	Houston, Stewart	3 hr
Aug 21, 4:55 PM CDT	Flash Flood Warning	OHX	Dickson, Hickman, Houston, Humphreys	6 hr
Aug 21, 5:07 PM CDT	Flash Flood Warning	OHX	Dickson, Houston, Montgomery, Stewart	4 hr
Aug 21, 5:10 PM CDT	Special Weather Statement	OHX	Houston, Stewart	50 min
Aug 21, 5:30 PM CDT	Special Weather Statement	OHX	Dickson, Houston	45 min
Aug 21, 5:43 PM CDT	Special Weather Statement	OHX	Lawrence	47 min
Aug 21, 5:57 PM CDT	Tornado Warning	OHX	Dickson	16 min
Aug 21, 5:58 PM CDT	Flash Flood Warning	OHX	Cheatham, Dickson, Houston, Montgomery	3 hr
Aug 21, 6:17 PM CDT	Special Weather Statement	OHX	Dickson	43 min
Aug 21, 6:29 PM CDT	Special Weather Statement	OHX	Hickman	31 min
Aug 21, 6:53 PM CDT	Special Weather Statement	OHX	Williamson	37 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.