A wake low developed on the back side of a complex of showers that moved through during the overnight and early morning hours of the 24th. From approximately 7:30 AM through 9:30 AM, easterly winds increased into the 25-30 mph range with gusts of 35 to 40 mph reported from parts of northwest through north central Alabama.
Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
A wake low developed on the back side of a complex of showers that moved through during the overnight and early morning hours of the 24th. From approximately 7:30 AM through 9:30 AM, easterly winds increased into the 25-30 mph range with gusts of 35 to 40 mph reported from parts of northwest through north central Alabama. The winds knocked down a few trees in Colbert, Morgan and Madison Counties, and knocked over tents that were being set up for the Panoply Art Festival in downtown Huntsville. Power outages were also reported in southwest Huntsville. In Morgan County at Decatur, the Morgan County Rescue Squad assisted fishing tournament participants on Wheeler Reservoir including several boats that tipped over by the gusty winds and rough water and three foot waves.
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 Apr 24, 5:34 AM CST, 56 minutes earlier.
Area Forecast Discussion National Weather Service Huntsville AL 634 AM CDT Sat Apr 24 2021 .UPDATE... For 12Z TAFS. && .NEAR TERM...(Today) Issued at 351 AM CDT Sat Apr 24 2021 Light to moderate rainfall is currently overspreading the area as a mid-level shortwave continues to lift northeast through the Ozark Plateau, providing lift combined with a sfc low tracking northeast through the ArkLaMiss region. Rain will continue through the remainder of the morning before clearing the area at least briefly this afternoon. The lack of any real instability has kept lightning at bay so far, and believe this will continue through the remainder of this morning wave of rain. Should see temperatures warm to the mid 60s by late morning. Today will be one of those days where mesoanalysis is especially important, as often times high res guidance struggles to gain a handle on observational trends. We do believe north Alabama and southern middle Tennessee will see a break from the rainfall around noon. This should allow for some diurnal heating, but it remains unclear how much thinning of cloud cover we will see. The SPC HREF indicates a good bit of clearing, with only scattered afternoon cu development by around 20z. Overall, model consensus shows temperatures warming into the upper 60s/lower 70s during the 18-23z timeframe, steepening low level lapse rates and allowing sfc based instability to rise into the 1000-1500 J/kg range. To our benefit, shear parameters really begin to drop off during this afternoon timeframe, keeping the primary tornado concern well to our south. The main question is, what will be the forcing mechanism for an afternoon round of storms? It is difficult to determine that at this timeframe, but there is certainly the potential for a remnant outflow boundary either from this morning's rain or from a decaying MCS expected to move through the lower MS Valley this morning. All of this to say, the forecast for this afternoon remains very uncertain, but the risk for hail and damaging winds is worth mentioning should any thunderstorms develop. Believe the primary window for strong/severe storms will be from 3-8pm. .SHORT TERM...(Tonight through Monday) Issued at 351 AM CDT Sat Apr 24 2021 Any lingering showers and/or storms should come to an end shortly after sunset with the loss of diurnal heating. Will see some low level cloud cover overnight, but this will begin a dry weather period that will last through the remainder of the short term period, as an upper level ridge begins building over the Southern Plains and sfc high pressure moves over the lower Ohio River Valley. Temperatures will top out in the lower 70s on Sunday with abundant sunshine throughout the day. Will see much of the same on Monday, only our temperatures will climb about 10 degrees warmer, being one of the few 80+ degree days we have had so far this year. Overnight lows will be in the 50s each night. .LONG TERM...(Monday night through Friday) Issued at 351 AM CDT Sat Apr 24 2021 An upper-level ridge will become centered just east of the Tennessee Valley, resulting in a substantial warm up across our area for Tuesday as deep southerly flow helps to advect in a warm, moist air mass. This combined with plenty of sunshine should help to push highs well into the low to mid 80s both days (even with some denser cloud cover on Wednesday). The tranquil weather will come to an end by late in the week as a strong upper-level storm system is posed to impact the Tennessee Valley late in the period. Some considerable uncertainty remains amongst the global models and their ensembles regarding the timing of this system as well as the track of some the key features that will have a big impact on the storm environment. Latest model trends continue to be slower with this system. The GFS is the more progressive solution, pushing the cold front and the associated shower/thunderstorm activity through the area about 12-18 hours faster than the ECMWF (Wednesday night into Thursday morning as opposed to Thursday evening/night). Confidence is fairly high that we will see a period of high PoPs somewhere during this window, but have capped them at 50 percent for now, given the uncertainty that remains. This will need to be revisited in later updates as confidence in timing increases. The strong dynamics with this system and the presence of a warm, moist environment ahead of it means there could be the potential for a round of strong storms during this window. This will be dependent on the environmental parameters in place and the where the key mesoscale features align themselves. Confidence/predictability in this is still fairly low at this time 5-6 days out, so we'll have to continue to monitor the progression of this system, model trends, etc in future updates. Behind the front, expect a cooler air mass to move in by Friday into the weekend. Depending on the evolution of the aforementioned upper- level trough, a cut-off low may develop over the Deep South. This would lead to additional rounds of light precipitation, cloud cover, and below normal temperatures during this period. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) Issued at 634 AM CDT Sat Apr 24 2021 IFR to MVFR conditions prevail over the area as widespread rain tracks northeast this morning. Believe this activity will come to an end within the next hour or two at KMSL and shortly after that at KHSV. Beyond this, considerable uncertainty exists regarding additional showers and storms later this afternoon. Believe MVFR flight conditions will prevail through much of the day, with wind gusts as high as 25kts at times. Due to the uncertainty with storms this afternoon, have gone with vicinity thunderstorms at both terminals through the evening hours. Subsequent updates might warrant prevailing thunder if confidence increases. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && NEAR TERM...25 SHORT TERM...25 LONG TERM...AMP.24 AVIATION...25 For more information please visit our website at weather.gov/huntsville.
Hazardous Weather Outlook National Weather Service Huntsville AL 630 AM CDT Sat Apr 24 2021 ALZ001>010-016-TNZ076-096-097-250230- Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan- Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN- 630 AM CDT Sat Apr 24 2021 This Hazardous Weather Outlook is for north Alabama and portions of southern middle Tennessee. .DAY ONE...Today and Tonight... Isolated to scattered thunderstorms are possible this afternoon and evening. A few of these storms could become strong to severe in intensity. Large hail and damaging wind gusts will be the main threats. .DAYS TWO THROUGH SEVEN...Sunday through Friday... A strong storm system will approach the Tennessee Valley late this week. Scattered thunderstorms will be possible Wednesday night through Friday, depending on the timing of this system and its associated cold front. A few of these storms could be strong. .SPOTTER CALL TO ACTION STATEMENT... Activation of storm spotters and emergency management personnel is possible this afternoon and evening. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines.
The national radar mosaic for the moment the first event began.
3 strong wind. Local standard time, as filed.
A few trees were knocked down in Colbert County.
In Morgan County at Decatur, the Morgan County Rescue Squad assisted fishing tournament participants on Wheeler Reservoir including several boats that tipped over by the gusty winds and rough water and three foot waves. No one was injured. A few trees were also knocked down in Morgan County.
A few tents were knocked over at an art festival in downtown Huntsville. No injuries were reported. Damages were not specified.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alabama in 2021Every state in 2021This day in weather historyWarnings in Alabama, April 2021
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: 956864, 956865, 956866.