To set the stage, a great deal of rain fell over the previous week, including over 3 inches the previous weekend, another storm that dropped more than an inch mid-week, and finally another inch-plus over the weekend on which the storm damage occurred, leaving the ground saturated and vulnerable to falling trees in the high wind.
Early morning storm
The first round of strong storms in Bartlett occurred between 8:30-9:00pm. Here's a radar loop that ends around 8:15, just prior to the storms reaching Bartlett.8:20 AM - The main line of heavy rain and thunderstorms is now pushing through Memphis proper. More to follow the line too. #memstorm /AH pic.twitter.com/hTeBKoE5zo— MemphisWeather.net (@memphisweather1) April 30, 2017
Those storms produced straight-line wind that uprooted 5-6 mature trees, including the very large oak shown below, near and just southwest of the intersection of Billy Maher Road and Old Brownsville on the north side of Bartlett. No warning was in effect at the time.
Late morning storm
Behind that storm, another severe storm embedded in a larger area of heavy rain raced north at 55 mph through east Memphis and into Bartlett between 11:30-12:00pm. This storm was warned in advance for the likelihood of high wind. Here is the radar wind velocity loop from that storm, which shows the light blue colors (wind of about 60 mph) moving over Bartlett at 11:40am:This storm cause more extensive damage. In fact, I was able to trace an approximate path based on fallen trees from Stage Road and Kirby-Whitten in the middle of Bartlett north to Old Brownsville Road east of Oak Road, a distance of nearly 4 miles. The map below shows the areas where fallen trees and damage occurred, with the most extensive damage on Broadway Street south of Shadowlawn Road, where 4-5 mature, large oak trees were uprooted. In addition, in the Easthill subdivision south of the Broadway damage, multiple large trees were also uprooted, including one that fell over a house, splitting it in two. Just south of the Easthill subdivision, in the wooded Bartlett-Ellendale Cemetery, one large oak tree was snapped off about 30 feet above the ground. Pictures of this damage are shown below.60+MPH winds pushing north thru Bartlett, TN right now. Take cover! #Tnwx pic.twitter.com/R3Xc75g9oU— NWS Memphis (@NWSMemphis) April 30, 2017
Based on damage indicators and degree of damage used by the National Weather Service, in my estimation the straight-line wind associated with each event was likely severe (60 mph or stronger) with roughly 75 mph wind gusts required to uproot trees of the size that were toppled. The trees that were snapped off could have seen wind gusts of 80+ mph. This wind is equivalent to an EF-0 to low-end EF-1 rating had it been a tornado. However, there are no indications from my unofficial assessment that a tornado occurred in these cases.
Tipton County Tornado
Finally, I'll end with the official NWS survey of a tornado that occurred nearly at the same time as the early damage in Bartlett. An EF-0 caused minor damage in Covington, TN, in Tipton County. Here is the NWS survey report:.Tornado in Covington Tennessee... Rating: EF0 Estimated Peak Wind: 75 MPH Path Length /Statute/: 2.1 miles Path Width /Maximum/: 100 yards Fatalities: None Injuries: None Start Date: Apr 30 2017 Start Time: 0846 AM CDT Start Location: 1.6 S Covington Start Lat/Lon: 35.5403/-89.6447 End Date: Apr 30 2017 End Time: 0850 AM CDT End Location: 0.9 ENE Covington End Lat/Lon: 35.5699/-89.6341 SURVEY SUMMARY: Damage primarily to trees and power poles. Minor damage to Crestview Middle School.
Erik Proseus
MWN Meteorologist
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