A fast-moving line of showers and thunderstorms pushed through north Alabama from west to east during the early morning hours of the 23rd. Damaging winds snapped a power pole.
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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 fast-moving line of showers and thunderstorms pushed through north Alabama from west to east during the early morning hours of the 23rd. Damaging winds snapped a power pole. There were also reports of trees knocked down.
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 Dec 23, 5:34 AM CST, 12 minutes earlier.
Area Forecast Discussion National Weather Service Huntsville AL 534 AM CST Sat Dec 23 2017 .UPDATE... For 12Z TAFS. && .NEAR TERM...(Today) Issued at 257 AM CST Sat Dec 23 2017 Latest water vapor imagery shows an upper level shortwave moving into the Mississippi Valley, helping to push a surface cold front eastward. This front currently stretches from its parent low over the eastern Great Lakes, southwestward through the Midsouth region and into southeast Louisiana and was moving fairly quickly to the east. The 02 am surface analysis shows another area of low pressure that has developed along the southern extent of the cold front over western Tennessee. This has increased the pressure gradient across the TN Valley, with southerly surface winds gusting as high as 30 mph in some locations. The strong southerly flow has advected much warmer and more moist air across the region, with temperatures in the upper 60s to lower 70s and dewpoints in the lower 60s. Area radars show an area of showers, with isolated thunderstorms, on the doorstep of northwest Alabama just ahead of the cold front. This activity will push into northwest Alabama within the next hour and then quickly translate eastward through the morning. Short term guidance seems to be handling the current conditions fairly well and are in fair agreement that the rain will move east of I-65 by 15Z and then out of northeast Alabama by the early afternoon hours, with the cold front trailing just behind the precip. There still appears to be a small window for isolated storms to become strong to severe. At this point, most of the convection associated with the front remains south of the I-20 corridor in Mississippi, however a few lightning strikes have been observed further north. The main limiting factor at this point is an inversion around the 700 mb layer, keeping the instability fairly minimal. With that said, the dynamics associated with this system are fairly impressive as the low level jet moves over the TN Valley. This jet was producing speeds up to 60 kts around 925 mb and with southerly flow at the surface and southwest flow just above the surface, low level wind shear was approaching 35 kts and deep layer shear around 80 kts. Given these numbers, it won't take much for any storm to exhibit supercellular structures, but again this will be dependent on if the area will realize any surface based instability. At this point, hires forecast soundings show the inversion eroding as the shortwave continues to move eastward, but the question remains if this will be ahead of the cold front. As already stated, there will be a very narrow window just ahead of the front for these parameters to come in line and become favorable for an isolated severe thunderstorm. Of course a brief tornado is certainly possible, but the higher threat will be isolated damaging wind gusts. Based on the latest guidance, the highest chance for this to occur will be just before sunrise across the NW and ending in the SE by 18Z. The cold front will quickly push east of the area by early afternoon, ending the precip across the area. Cold air advection behind the front will be very efficient, with temperatures dropping rapidly into the upper 40s to lower 50s by the afternoon. .SHORT TERM...(Tonight through Monday) Issued at 257 AM CST Sat Dec 23 2017 Clouds will linger across the area through the overnight hours, tempering the cooling just a bit. Even still, the CAA will continue and temperatures will fall into the mid to upper 30s. Christmas Eve will be fairly chilly, especially compared to the previous few days, with clouds persisting through the day. A broad upper trough will swing through the region, and there might be just enough moisture left for isolated light showers to develop across the northeast portion of the forecast area Sunday afternoon. With temps remaining above freezing, only looking at the potential for liquid precip. A reinforcing cold front will then sweep through the area Sunday night and the dry air will overcome any lift and limit the chance for frozen precip. However, even colder conditions are forecast for Christmas Eve night and Christmas day as cold air advection increases behind the aforementioned cold front. Overnight lows will drop into the mid 20s and highs will only warm into the lower 40s. .LONG TERM...(Monday night through Friday) Issued at 257 AM CST Sat Dec 23 2017 Uncertainty increases in the long term as forecast models diverge on their solutions. Near zonal flow will be in place to start the period, with easterly surface winds filtering in slightly more moist air. A cold start to the morning will give way to seasonable afternoon highs, with temperatures warming into the upper 40s. A weak shortwave will develop along the central Gulf of Mexico late on Tuesday and then begin to move northeastward as weak ridging across the eastern Caribbean builds northward. The GFS is a bit more progressive with this system, bringing precip into the area as early as Wednesday afternoon and continuing through Saturday. Meanwhile, the ECMWF keeps most of the precip to our south until Thursday night. Along with a wetter pattern, the GFS is also slightly warmer, with above freezing temperatures through Thursday night. It then cools the vertical column as winds become northerly and filter in colder air. Of course, the ECMWF is colder, but also dry for the most part. Given the uncertainties with the long term, have kept to blended guidance. This does mean that there are a few periods with rain transitioning to snow, but no accumulations are expected at this point. Again, we're talking days 5 through 7. High temperatures through the period will generally remain in the 40s, with overnight lows in the 30s through Friday and then dropping into the upper 20s. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) Issued at 534 AM CST Sat Dec 23 2017 A line of showers, with embedded thunderstorms, will move through the region this morning. This line will reach the KMSL terminal by 6 am and then KHSV by 8 am. This line will produce brief instances of heavy rainfall and wind gusts up to 40 kts. This line will clear the terminals by 10 am. Meanwhile, a cold front will pass through the terminals just behind the line with winds becoming northwesterly. These winds will continue to gust up to 25 kts through the remainder of the morning. Low clouds will persist through the period, with IFR cigs expected by 15Z just behind the front. These clouds will lift to around 2000 feet by 18Z and persist through evening hours and then lower to around 900 feet after 08Z. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && NEAR TERM...73 SHORT TERM...73 LONG TERM...73 AVIATION...73 For more information please visit our website at weather.gov/huntsville.
Hazardous Weather Outlook National Weather Service Huntsville AL 332 AM CST Sat Dec 23 2017 ALZ001>010-016-TNZ076-096-097-241130- Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan- Marshall-Jackson-De Kalb-Cullman-Moore-Lincoln-Franklin TN- 332 AM CST Sat Dec 23 2017 This Hazardous Weather Outlook is for north Alabama and portions of southern middle Tennessee. .DAY ONE...Today and Tonight... Showers and embedded thunderstorms will continue to track eastward this morning along a cold front. A few strong to severe storms will be possible, with the primary threats coming from damaging wind gusts up to 60 mph and brief tornadoes. Locally heavy rainfall may also result in minor flooding of creeks, streams and other low lying areas. The threat for storms will end for the northwest half of the outlook area by 9 AM and for the remainder of the region by Noon. .DAYS TWO THROUGH SEVEN...Sunday through Friday... The probability for widespread hazardous weather is low. A developing storm system along the Gulf coast will bring a low chance of snow to the region on Thursday night and Friday. .SPOTTER CALL TO ACTION STATEMENT... Limited activation of storm spotters and emergency management personnel is possible through Noon today. 70/DD
The Columbus AFB radar (KGWX), 125 km away, was scanning. The volume nearest the first event began at 11:46 UTC.
4 thunderstorm wind. Local standard time, as filed.
A power pole was snapped and lines knocked down on Baker Road.
A few trees were knocked down on CR 14 east of Waterloo. Time estimated by radar.
A tree was knocked down partially blocking the intersection of CR 61 and CR 335. Time estimated by radar.
A tree was knocked down causing partial blockage of the road near CR 88 at CR 51. Time estimated by radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alabama in 2017Every state in 2017This day in weather historyWarnings in Alabama, December 2017
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: 726675, 726676, 726677, 726678.