A stationary frontal boundary stalled across the central portions of Middle Tennessee from Saturday, September 12, 2020 into Sunday, September 13, 2020. Persistent southwest flow aloft brought copious amounts of Gulf of Mexico moisture northward and interacted with this boundary, causing a roughly 7 hour period of nearly continuous heavy rain and thunderstorms.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS OHX wrote it up.
A stationary frontal boundary stalled across the central portions of Middle Tennessee from Saturday, September 12, 2020 into Sunday, September 13, 2020. Persistent southwest flow aloft brought copious amounts of Gulf of Mexico moisture northward and interacted with this boundary, causing a roughly 7 hour period of nearly continuous heavy rain and thunderstorms. Rainfall totals reached 5 to over 8 in some locations, resulting in major flash flooding and river flooding along a narrow corridor across Lawrence, Lewis, Maury, Williamson, Davidson, Rutherford, Wilson, Sumner, and Macon Counties. Numerous water rescues were conducted and many homes and businesses were flooded, with some of the worst flooding occurring in the Mill Creek basin across northeast Williamson County and southeast Davidson County. In fact, Mill Creek at Nolensville reached 19.53 feet, which is the second highest crest ever at that location - only surpassed by the record of 22.53 feet in the May 2010 flood.
The local office's own words before the first event, 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 the first event at Sep 13, 5:49 AM CST, 1 hour 26 minutes earlier.
Area Forecast Discussion National Weather Service Nashville TN 649 AM CDT Sun Sep 13 2020 .UPDATE... FOR 12Z AVIATION DISCUSSION. && .DISCUSSION... Tweaked hourly temperature, dewpoint, and wind speed/direction grids. Freshened up wording in zone forecast product for flash flood watch. Remainder of forecast continues to be on track. && .AVIATION... 12Z TAF DISCUSSION. MVFR to IFR conditions persist at BNA/MQY with SHRA/TSRA this morning. CKV/CSV vary between VFR and MVFR CIGs. More SHRA/TSRA is on the way for BNA/MQY in the next several hours, while CSV will have to wait until 18z for any activity. Heavier rain will reduce VIS/CIGs to MVFR or IFR at times. Activity will taper off around 00z or a little sooner. Light south winds become northerly/variable this afternoon and evening. MVFR CIGs are possible at BNA/MQY/CSV and may need further adjustment in later TAF cycles. && .OHX WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch through this evening for Bedford-Clay-Davidson- Giles-Hickman-Jackson-Lawrence-Lewis-Macon-Marshall-Maury- Overton-Perry-Pickett-Putnam-Rutherford-Smith-Sumner-Trousdale- Wayne-Williamson-Wilson. && DISCUSSION......JB Wright AVIATION........Schaper
Hazardous Weather Outlook National Weather Service Nashville TN 518 AM CDT Sun Sep 13 2020 TNZ005>011-023>034-056>066-075-077>080-093>095-141000- 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- 518 AM CDT Sun Sep 13 2020 This Hazardous Weather Outlook is for Middle Tennessee. .DAY ONE...Today and tonight. A good portion of the mid state will experienced between two to three inches, with locally higher amounts of around five inches, of rainfall today. Heavy rainfall could fall within a short period of time causing flooding of streets and low lying areas. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Currently, the greatest rainfall amounts associated the remants of Tropical Storm Sally will be across southeastern portions of the mid state region later this work week where two to four inches of rainfall could be possible. .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. JB Wright
The Nashville radar (KOHX), 31 km away, was scanning. The volume nearest the first event began at 13:12 UTC.
21 flash flood, 2 heavy rain. Local standard time, as filed.
Waller Road was closed due to high water.
Major flash flooding affected the Nolensville area. Several homes, businesses, and other buildings were flooded. Some of the buildings flooded included the Williamson County Parks and Recreation Center, located at 7250 Nolensville Road, which suffered damage estimated at $321,663.47; the Mill Creek Church of Christ at 7260 Nolensville Road; and the historic Nolensville School at 7248 Nolensville Road. Numerous roads were also flooded and closed including Baronswood Drive, Kidd Road, Nolensville Road, Sunset Road, York Road, Old Clovercroft Road, Summerlyn Drive, Oldham Drive, Concord Road, Rocky Springs Road, Rocky Ford Road, Stonebrook Blvd., Dortch Lane, McFarlin Road, Fly Road, and Brittain Lane. The Brittain Lane bridge over Mill Creek was damaged by the flooding and indefinitely closed. Five water rescues were conducted in the area with many vehicles submerged.
Water rescue ongoing at Culbertson Road.
Flood waters surrounded several homes on Mercury Drive in La Vergne.
Photos showed Wolverine Trail near Sam Ridley Parkway was flooded and impassable, with one car submerged in the flood waters.
Desha Creek flooded Wrights Lance and the road is impassable.
Miles Johnson Parkway at Duplex Road was flooded and closed.
Old Shackle Island Road was closed due to flooding.
Several roads were flooded and closed around Mount Pleasant.
Old Lebanon Dirt Road was closed 1.5 miles west of Mount Juliet Road due to high water.
Flood waters were three feet deep at the intersection of Couchville Pike and McCrary Road.
Significant flash flooding caused several shipping containers at the Bridgestone Plant to float to Bridgestone Parkway.
I-24 was closed at Bell Road due to water over the interstate around Blue Hole Road.
Multiple water rescues were conducted from homes around West Sheepneck Road at Lawrenceburg Highway.
Multiple roads were flooded and closed in Columbia.
Santa Monica Blvd. and Hollywood Blvd. were flooded with water approaching homes.
Multiple water rescues ongoing in the northern part of Lawrence County.
Flood waters covered the road at Rock Springs Road and Rogana Road.
Lawrence County Emergency Management reported on their Facebook page that numerous agencies were responding to flash flooding across northern Lawrence County. Numerous trees fell from flood waters and at least one water rescue occurred.
CoCoRaHS station Brentwood 1.9 ESE measured a storm total of 8.25 inches of rain.
Highway 231 was flooded and closed south of Lebanon Square.
CoCoRaHS station Nolensville 2.4 SW measured a storm total of 6.74 inches of rain.
Numerous photos from Maury County EMA showed flash flooding near Mount Pleasant. A bridge over Big Bigby Creek at Canaan Road and Ashwood Road was flooded, as were Magnolia Road and Sugar Creek Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2020Every state in 2020This day in weather historyWarnings in Tennessee, September 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 921829, 921830, 921831, 921832, 922545, 921833, 921834, 921835, 921836, 921837, 921838, 921839, 921840, 921841, 921846, 921847, 921848, 921849, 921850, 921853, 921851, 922544, 921852.