Alert archive / Tennessee / Flash Flood Watches in 2020

Flash Flood Watch 5, NWS Nashville, TN

August 28, 202021 counties in Tennessee

NWS Nashville, TN issued this flash flood watch at Aug 28, 2020, 2:14 AM CDT for 21 counties in Tennessee. It took effect at Aug 28, 2020, 12:00 PM CDT. It was in force for 10 hr.

The area

The counties it named.

The facts

Issued: Aug 28, 2020, 2:14 AM CDT (07:14 UTC)
In effect from: Aug 28, 2020, 12:00 PM CDT
Expired: Aug 28, 2020, 9:59 PM CDT
In force: 10 hr
Issued by: NWS Nashville, TN
Flood severity: None

All 21 counties

Bedford County, TN, Cheatham County, TN, Davidson County, TN, Dickson County, TN, Giles County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Marshall County, TN, Maury County, TN, Montgomery County, TN, Perry County, TN, Robertson County, TN, Rutherford County, TN, Stewart County, TN, Sumner County, TN, Wayne County, TN, Williamson County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 65 km from the middle of the area, began a volume at 07:14 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, 7.2 hours before the alert went out and 280 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: 582 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -48 m²/s²
0-3 km storm-relative helicity: 78 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 flash flood watch 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 flash flood watch went out at Aug 27, 11:39 PM CDT, 2 hours 35 minutes earlier.

Area forecast discussion, Aug 27, 11:39 PM CDT, 2 hours 35 minutes before

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Hazardous weather outlook, Aug 27, 5:02 AM CDT, 21 hours 12 minutes before

Hazardous Weather Outlook
National Weather Service Nashville TN
502 AM CDT Thu Aug 27 2020

TNZ005>011-023>034-056>066-075-077>080-093>095-281015-
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-
502 AM CDT Thu Aug 27 2020

This Hazardous Weather Outlook is for Middle Tennessee.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

The remnants of Hurricane Laura are expected to move across Middle
Tennessee Friday afternoon through early Saturday morning. Gusty
winds will accompany Laura with localized wind damage possible,
including a few downed trees and scattered power outages. An
isolated tornado or two may occur across Middle Tennessee from late
Friday afternoon through early Saturday morning. Heavy downpours
could cause brief localized flooding.

.SPOTTER INFORMATION STATEMENT...

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

13

In the hours before

Special weather statement, Aug 27, 8:46 PM CDT, 5 hours 28 minutes before

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Local storm report, Aug 27, 10:53 PM CDT, 3 hours 21 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
Aug 27, 7:50 PM CDT	Special Weather Statement	OHX	Davidson	40 min
Aug 27, 8:46 PM CDT	Special Weather Statement	OHX	Davidson	29 min
Aug 28, 11:21 AM CDT	Severe Thunderstorm Warning	OHX	Hickman, Lewis, Perry	24 min
Aug 28, 11:24 AM CDT	Special Weather Statement	OHX	Dickson	36 min
Aug 28, 11:37 AM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Dickson, Houston, Humphreys, Montgomery	23 min
Aug 28, 11:45 AM CDT	Severe Thunderstorm Warning	OHX	Dickson, Hickman, Lewis, Maury, Williamson	30 min
Aug 28, 11:52 AM CDT	Special Weather Statement	OHX	Giles, Lawrence	38 min
Aug 28, 12:01 PM CDT	Tornado Warning	OHX	Dickson, Hickman, Maury, Williamson	14 min
Aug 28, 12:13 PM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Davidson, Dickson, Hickman, Maury, Williamson	28 min
Aug 28, 12:14 PM CDT	Tornado Warning	OHX	Cheatham, Dickson, Hickman, Williamson	17 min
Aug 28, 12:24 PM CDT	Special Weather Statement	OHX	Giles, Lawrence	51 min
Aug 28, 12:33 PM CDT	Severe Thunderstorm Warning	OHX	Maury	27 min
Aug 28, 12:40 PM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Davidson, Robertson	35 min
Aug 28, 12:47 PM CDT	Tornado Warning	OHX	Davidson	28 min
Aug 28, 12:54 PM CDT	Severe Thunderstorm Warning	OHX	Davidson, Maury, Williamson	36 min
Aug 28, 1:11 PM CDT	Special Weather Statement	OHX	Sumner	49 min
Aug 28, 1:22 PM CDT	Severe Thunderstorm Warning	OHX	Davidson, Rutherford, Sumner, Williamson, Wilson	38 min
Aug 28, 1:25 PM CDT	Special Weather Statement	OHX	Bedford, Marshall, Rutherford	50 min
Aug 28, 1:55 PM CDT	Special Weather Statement	OHX	Macon, Smith, Trousdale, Wilson	65 min
Aug 28, 3:09 PM CDT	Special Weather Statement	OHX	Lawrence, Wayne	36 min
Aug 28, 3:17 PM CDT	Special Weather Statement	OHX	Dickson, Hickman, Lewis	28 min
Aug 28, 3:44 PM CDT	Special Weather Statement	OHX	Giles, Lawrence, Maury, Williamson	31 min
Aug 28, 3:49 PM CDT	Areal Flood Advisory	OHX	Lawrence, Wayne	101 min
Aug 28, 4:16 PM CDT	Special Weather Statement	OHX	Bedford, Marshall, Rutherford	44 min
Aug 28, 4:39 PM CDT	Special Weather Statement	OHX	Coffee	36 min
Aug 28, 4:49 PM CDT	Special Weather Statement	OHX	Giles	26 min
Aug 28, 5:01 PM CDT	Special Weather Statement	OHX	Bedford	29 min
Aug 28, 5:16 PM CDT	Special Weather Statement	OHX	Warren	29 min
Aug 28, 5:32 PM CDT	Special Weather Statement	OHX	Coffee	28 min
Aug 28, 5:45 PM CDT	Tornado Warning	OHX	Warren	15 min
Aug 28, 6:00 PM CDT	Special Weather Statement	OHX	Van Buren	30 min
Aug 28, 6:15 PM CDT	Special Weather Statement	OHX	White	30 min
Aug 28, 6:38 PM CDT	Special Weather Statement	OHX	White	37 min
Aug 28, 6:52 PM CDT	Special Weather Statement	OHX	Overton	38 min
Aug 28, 6:54 PM CDT	Tornado Warning	OHX	Cumberland, Overton, Putnam, White	16 min

Nearby

Flash Flood Watches in Tennessee, 2020 Every flash flood watch in 2020

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.