Clusters of thunderstorms developed during the early to mid afternoon hours in northwest Alabama. These produced gusty winds that knocked down a couple of trees in Colbert County.
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 HUN wrote it up.
Clusters of thunderstorms developed during the early to mid afternoon hours in northwest Alabama. These produced gusty winds that knocked down a couple of trees in Colbert County.
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 Huntsville, AL wrote its last area forecast discussion before the first event at Aug 13, 11:46 AM CST, 1 hour 52 minutes earlier.
Area Forecast Discussion National Weather Service Huntsville AL 1246 PM CDT Thu Aug 13 2020 .UPDATE... For 18Z TAFS. && .NEAR TERM...(Rest of Today) Issued at 1055 AM CDT Thu Aug 13 2020 Late morning analysis continues to indicate the best broader scale forcing from an upper level low mainly to our west. Showers and thunderstorms can be seen in radar and multi-spectral satellite imagery developing along a line well to our W to SW...from the Southern Plains into the Lower Miss Valley. Nevertheless, the local air mass will become increasingly unstable into the afternoon with daytime heating under partly cloudy sky conditions. Atmospheric moisture content remains rather high with PW values around or slightly greater than 2 inches. ML CAPE values around 2 KJ/KG and low-lvl lapse rates greater than 7 C/km indicate a decent gusty wind threat with the strongest convection. An isolated damaging wind threat does exist. In addition, outflow boundaries propagating from convection to our west will be possible especially as the afternoon progresses, and may give rise to new thunderstorm development. .SHORT TERM...(Tonight through Saturday night) Issued at 353 AM CDT Thu Aug 13 2020 As has been the case the past few days, shower activity should diminish this evening with a loss of daytime heating. Low temperatures by Friday morning should range in the lower 70s. Even better rain chances will end the work week, with deep moisture in place and more daytime heating produced instability. Went for widespread rain chances for parts of the Valley Fri afternoon. The usual torrential downpours, gusty winds and frequent lightning again are possible in the stronger storms. A moist profile in forecast soundings appears more favorable for rain makers rather than strong convection. With better rain chances, highs on Fri should be cooler, in the mid 80s. Troughing will continue deepening over the eastern lower-48 on Saturday. A weak area of low pressure over the region will continue rain chances, although not as high like on Fri. Despite the lower heights, more solar insolation should help boost highs into the mid/upper 80s to round out the week. But it should cool down a bit more for Sat night, with lows in the upper 60s to around 70. .LONG TERM...(Sunday night through Wednesday) Issued at 353 AM CDT Thu Aug 13 2020 A very amplified trough axis over the eastern CONUS continues into Sunday. Although the initial front will be well to the southwest of the Tennessee Valley very early Sunday morning, a second reinforcing front moves from the western Great Lakes region southeast towards the Tennessee and Ohio Valleys during the remainder of the day. The forcing along and ahead of the front does not look that strong. Shear is not strong either. However, with some decent SBCAPE and decent moisture convergence by the mid-afternoon hours, forcing with this secondary front looks close enough to northwestern Alabama to produce scattered shower and thunderstorm activity at the very least. East of the I-65 corridor, precipitation chances are less certain. For now, kept closer to the high end of guidance for high temperatures, thinking that cloud cover and precipitation chances will mainly occur in the mid/late afternoon hours. Overall, these storms don't look overly strong. Models seem to slowly but steadily move this secondary front southeast into southern Alabama/Georgia Sunday night into Monday morning. Much drier and cool air for this time of year is shown advecting into the area by NW to NNW winds aloft. Despite sunshine returning to the forecast, temperatures will likely only climb into the mid to upper 80s Monday through Wednesday of next week. Quite cool for the middle of August (typically highs are in the lower 90s). Not so sure lows will be too far below normal, but could be around 5 degrees below normal (mainly in the lower to mid 60s) in typical valley locations and in southern middle Tennessee. By Wednesday into Thursday, a surface low rides up the east coast along the stalled front extending from Georgia into the Carolinas. This could wrap around some shower or thunderstorm activity back into the area, especially east of the I-65 corridor. Re-introduced scattered to likely pops in the forecast both days. This should keep high temperatures well below normal, primarily in the lower to mid 80s. Again, shear doesn't look impressive at this time. Though enough instability will be in place for some thunderstorm activity. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1242 PM CDT Thu Aug 13 2020 An upper trough is poised to the west of the region, which is helping to instigate more concentrated SHRA/TSRA activity mainly to our west today. However, a line of SHRA/TSRA has developed along the leading edge of this trough and may begin to impact KMSL by ~01Z and KHSV by ~02Z based on latest best timing estimate. The potential exists for MVFR cigs/vis with this activity at TAF sites, which could last for about 1 hour. Certainly lower IFR vis could occur if a strong core directly impacts a TAF site. Although, TAF updates may be necessary if other activity manages to develop in the unstable air mass ahead of the evolving line. More concentrated activity expected tomorrow as the upr trough moves into the area. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && NEAR TERM...KDW SHORT TERM...RSB LONG TERM...KTW AVIATION...KDW For more information please visit our website at weather.gov/huntsville.
Hazardous Weather Outlook...UPDATED National Weather Service Huntsville AL 1040 PM CDT Wed Aug 12 2020 ALZ001>010-016-TNZ076-096-097-131130- Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan- Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN- 1040 PM CDT Wed Aug 12 2020 This Hazardous Weather Outlook is for north central Alabama, northeast Alabama, northwest Alabama and southern middle Tennessee. .DAY ONE...Remainder of tonight. Scattered showers and thunderstorms will continue across portions of the region late this evening, before gradually dissipating after Midnight. Wind gusts of 30 to 35 MPH, frequent lightning and locally heavy rainfall will be the main hazards with the strongest storms. Due to slow storm motions, significant ponding of water on roads and minor flooding may also occur. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. Scattered to numerous thunderstorms are expected across the outlook area during the period from Thursday through Saturday, as an upper level disturbance tracks slowly eastward across the region. Although storm coverage will decrease heading into next week, a few storms will be possible each afternoon from Sunday through Tuesday. .SPOTTER INFORMATION STATEMENT... Activation of storm spotters and emergency management personnel is not anticipated at this time. 70/DD
The Columbus AFB radar (KGWX), 105 km away, was scanning. The volume nearest the first event began at 19:38 UTC.
2 thunderstorm wind. Local standard time, as filed.
A tree was knocked down at 2235 Mulberry Lane. Time estimated by radar.
A tree was knocked down at Rivermont Drive at Oak Hill Avenue in Sheffield. Time estimated by radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alabama in 2020Every state in 2020This day in weather historyWarnings in Alabama, August 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: 918026, 918027.