Alert archive / Tennessee / Areal Flood Advisories in 2021

Areal Flood Advisory 147, NWS Nashville, TN

September 19, 20217 counties in Tennessee

NWS Nashville, TN issued this areal flood advisory at Sep 19, 2021, 10:04 AM CDT for 7 counties in Tennessee. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Sep 19, 2021, 10:04 AM CDT (15:04 UTC)
Expired: Sep 19, 2021, 1:15 PM CDT
In force: 3 hr
Issued by: NWS Nashville, TN
Area: Storm-based polygon

Counties Bedford County, TN, Cannon County, TN, Coffee County, TN, Grundy County, TN, Marshall County, TN, Rutherford County, TN, Warren County, TN

The radar

The Northeast Alabama radar (KHTX), 75 km from the middle of the area, began a volume at 15:03 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 3.1 hours before the alert went out and 292 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: 896 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 611 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 29 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 Sep 19, 6:09 AM CDT, 3 hours 55 minutes earlier.

Area forecast discussion, Sep 19, 6:09 AM CDT, 3 hours 55 minutes before

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Hazardous weather outlook, Sep 19, 2:49 AM CDT, 7 hours 15 minutes before

Hazardous Weather Outlook
National Weather Service Nashville TN
249 AM CDT Sun Sep 19 2021

TNZ005>011-023>034-056>066-075-077>080-093>095-201000-
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-
249 AM CDT Sun Sep 19 2021

This Hazardous Weather Outlook is for Middle Tennessee.

.DAY ONE...Today and tonight.

A Flash Flood Watch is in effect for all of Middle Tennessee today
into tonight. Numerous showers and thunderstorms with moderate to
heavy rainfall are expected again today with several inches of
rainfall possible, before a break in rainfall occurs this evening
into tonight. The highest threat for flash flooding today will be
south of I-40, but flash flooding is possible throughout the area.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

A Flash Flood Watch will continue for all of Middle Tennessee
through Monday evening. Numerous additional showers and
thunderstorms with moderate to heavy rainfall are anticipated on
Monday which may lead to additional flash flooding. The highest
threat for flash flooding on Monday will be across southeast Middle
Tennessee, generally east of I-65 and south of I-40. Total rainfall
amounts from Sunday through Monday are expected to reach 1 to 3
inches across the area, with localized amounts of 4 to 6 inches
possible.

More showers and storms are expected along a strong cold front moving
through the area Tuesday night into Wednesday, but the flash flood
potential with this activity currently appears to be low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed today and again on Monday
due to the threat for flash flooding. Please relay any information
about observed flooding to the NWS while following all local, state,
and CDC guidelines.

Shamburger

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 19, 1:49 PM CDT	Areal Flood Advisory	OHX	Bedford, Coffee	6 hr
Sep 19, 4:02 PM CDT	River Flood Advisory	OHX	Bedford	10 hr
Sep 19, 4:13 PM CDT	Areal Flood Advisory	OHX	Bedford, Cannon, Coffee, Rutherford	3 hr

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.