A line of thunderstorms produced two brief tornadoes in northwest Alabama. The line continued east producing strong and damaging winds in a few locations in northwest Alabama before crossing the rest of north Alabama during the early morning hours of the 18th.
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.
A line of thunderstorms produced two brief tornadoes in northwest Alabama. The line continued east producing strong and damaging winds in a few locations in northwest Alabama before crossing the rest of north Alabama during the early morning hours of the 18th.
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 17, 11:20 AM CST, 19 minutes earlier.
Area Forecast Discussion National Weather Service Huntsville AL 1120 AM CST Sat Dec 17 2016 .UPDATE... For 18Z TAFS. && .NEAR TERM...(Rest of Today) Issued at 915 AM CST Sat Dec 17 2016 Surface low pressure located near the panhandle of Texas/Eastern New Mexico will continue to track northeast today. Ahead of it, strong WAA with southwesterly winds aloft have allowed temps to warm overnight and continue to warm with temps as of 9AM in the lower 60s in NW Alabama and lower 50s in NE Alabama. These will continue to warm to the upper 60s/near 70 by this afternoon. Winds have been slow to shift to the south but we are finally seeing dew points in the middle 40s to the upper 50s. Isolated to scattered showers ongoing now and Hires guidance supports this coverage continuing at least through the early afternoon so have dropped the pops to scattered through then. Winds have slackened a bit in the last 2-3 hours with gusts only around 15-20kt but generally just sustained of around 15kt. Looking at LAPS soundings, looks like the warming at the surface created a shallow inversion, inhibiting the strong winds from mixing down. As the column continues to warm this afternoon, the inversion will weaken and the gusts of 25kts should return. Sky cover could be tricky today. All guidance is showing us being completely cloudy today with low ceilings but out to the west, we are already seeing a few pockets of clearing skies. Guidance yesterday was suggesting there could be a brief break in the rain after around 21z today and this could correspond to a brief break in the clouds. Those features are difficult for the models to handle. If this break occurs, this would make us more unstable than previously forecast. An early glance at the hires guidance this morning shows we could still get some thunderstorms developing ahead of the main front late this evening as a short wave develops aloft. We are already going to have "some" instability given the dew points but if we clear out this will increase the instability. Given the continued lift from the SW, cloudy seems more likely. Either way, given the amount of shear, if we get a shortwave, storms could develop. Have left the mention of scattered thunderstorms in after 22z this evening. More updates may be necessary through the day in this regard. .SHORT TERM...(Tonight through Monday) Issued at 352 AM CST Sat Dec 17 2016 Widespread showers and thunderstorms are expected this evening as the above noted Arctic front nears. Given strong helicity values in the 400-500 m/s range and mixed CAPE values nearing 500 J/kg, some of the storms could become strong to severe in intensity. The main threat will be damaging wind gusts over 60 mph. Strong helicity values and lower enough LCL levels keeps a risk for brief tornado development in the picture, mainly in areas near/west of the I-65 corridor. This activity would be mainly ahead/with the front and/or QLCS type storms. Rainfall amounts should range in the inch range or so, with some spots receiving higher amounts. Now the cold front. Timing of this front was placing it across far NW AL around midnight tonight, sweeping quickly to the ESE and east of this forecast area by daybreak Sunday. Temperature falls with this front are 20-30 degrees per hour; expect similar rates across the area as Arctic air comes in from the NW. This much colder air (forecast temperatures at or just below freezing) plus falling precipitation spells a risk of wintry precipitation. Going with a top-down methodology, came up with upwards of 1/10 of an inch of ice accumulation. These amounts are close to Winter Weather Advisory criteria. However, think that a warm ground will hold, keeping icing on most ground surfaces minimized. Can't rule out a glaze on elevated or grassy areas when this occurs. Also have brief snow affecting mainly Lincoln/Moore counties of Tennessee as the change-over occurs in the late morning. Any precip should quickly end from NW-SE as drier air filters in. Have precipitation east of the region by the 4 PM Sunday afternoon timeframe. A sharp colder trend will continue Sunday night through Monday, with lows ranging from the upper teens NW AL to mid 20s NE Alabama. Winds in the 5-15 mph, gusting to 20 mph will produce wind chill values into the upper single digits, especially in more exposed locations. Highs on Monday will only range from the mid 30s NW Alabama to lower 40s NE Alabama, with the coldest air more over our western than eastern areas. .LONG TERM...(Monday night through Friday) Issued at 352 AM CST Sat Dec 17 2016 Most of the impact/sensible wx should be clr or e of the cntrl TN Valley by Mon night, as a large area of high pressure becomes layered from the Mid Atlantic region swwd into the srn Plains states. Morning temps Tue should be a bit higher compared to the bitter temps from early Mon, although readings will still be a few degrees below the freezing mark. As the sfc high weakens and drifts ewd during the day Tue, weak return flow will begin to develop across the Lower MS Valley and locations ewd. This should allow for a little bit of a warming trend, as afternoon highs approach 50F. Sly flow then begins to increase on Wed, thereby allowing Gulf moisture to increase into the region. Heading into Wed night, an upper trough axis moving ewd out of the Plains states is xpcted to interact with another cold front/sfc wave developing over the wrn Gulf region and will move across the area during the first half of Thu. Rainfall/showers are xpcted to develop along/ahead of the approaching front and it moves toward the e Wed night into Thu, with rain quickly tapering off from the w by Thu night. Not very much of a cool down is xpcted with this next sfc boundary, as high pressure returns from the srn Plains into the SE region in the wake of this next frontal passage. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) Issued at 1113 AM CST Sat Dec 17 2016 Complicated TAF forecast today with a few different issues. The first is the CIGS. They seem to finally be consistently lower to around 900-1000ft at both terminals which was fairly well forecast. The issue is we are starting to see some clearing in N. MS. At this time, just changed KMSL from OVC to BKN so nothing too impactful but that will have to be monitored. Should see on/off showers still through this evening before the front arrives around 6z at KMSL and 8z at KHSV. Did not add any thunderstorms ahead of this but if it does clear out, they may need to be added earlier. Winds will continue to be around 12-15kt sustained with occasional gusts to 20-23kt today. Higher gusts will accompany the thunderstorms along the front and upped those to 35kt. Winds will stay breezy through 18z Sunday. Last thing is the addition of -FZRA at KMSL for 11-14z. Only a trace of accumulation is expected and with it being windy and the ground being warm, it's uncertain how this will affect the runways. All of the timing in the TAF will need to be monitored and adjusted as the event unfolds. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && NEAR TERM...LN SHORT TERM...RSB LONG TERM...09 AVIATION...LN For more information please visit our website at weather.gov/huntsville.
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE HUNTSVILLE AL 457 AM CST SAT DEC 17 2016 ALZ001>010-016-TNZ076-096-097-181100- LAUDERDALE-COLBERT-FRANKLIN AL-LAWRENCE-LIMESTONE-MADISON-MORGAN- MARSHALL-JACKSON-DE KALB-CULLMAN-MOORE-LINCOLN-FRANKLIN TN- 457 AM CST SAT DEC 17 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH ALABAMA AND PORTIONS OF SOUTHERN MIDDLE TENNESSEE. .DAY ONE...TODAY AND TONIGHT... AN ARCTIC COLD FRONT WILL BRING A LINE OF STRONG TO MARGINALLY SEVERE THUNDERSTORMS ACROSS THE AREA LATE TONIGHT. THE PRIMARY IMPACT WITH THIS LINE OF STORMS WILL BE DAMAGING WINDS...ALTHOUGH THERE IS A LOW TORNADO THREAT MAINLY FOR LOCATIONS WEST OF INTERSTATE 65. THE THREAT FOR SEVERE WEATHER WILL END AROUND 1 TO 2 AM FOR NORTHWEST ALABAMA AND 3 TO 4 AM FOR THE REMAINDER OF THE OUTLOOK AREA. LIGHT RAIN WILL THEN TRANSITION TO LIGHT FREEZING RAIN AS THE ARCTIC AIRMASS ARRIVES IN THE AREA AROUND 6 AM SUNDAY MORNING...MAINLY FOR SOUTHERN MIDDLE TENNESSEE INTO NORTHWEST ALABAMA. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY... LIGHT ACCUMULATIONS OF ICE ARE POSSIBLE ACROSS SOUTHERN MIDDLE TENNESSEE INTO NORTHWEST ALABAMA THROUGH SUNDAY MORNING...WITH AMOUNTS GENERALLY LESS THAN A TENTH OF AN INCH...MAINLY ON ELEVATED SURFACES. TEMPERATURES ARE THEN EXPECTED TO PLUMMET SUNDAY NIGHT...WITH WIND CHILL VALUES FALLING INTO THE TEENS TO PERHAPS SINGLE DIGITS BY MONDAY MORNING. .SPOTTER CALL TO ACTION STATEMENT... ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT PERSONNEL IS POSSIBLE LATE TONIGHT.
The Columbus AFB radar (KGWX), 112 km away, was scanning. The volume nearest the first event began at 17:40 UTC.
10 thunderstorm wind, 2 tornado. Local standard time, as filed.
Multiple trees and power lines were knocked down in the Riverton area. Time estimated by radar.
A survey team from the National Weather Service and Colbert County Emergency Management investigated significant tree damage in the Riverton area. The damage was associated with a weak tornado embedded in a line of thunderstorms along a cold front. Numerous softwood trees were either uprooted or snapped just east of Bear Creek along Riverton Rose Trail. Damage was conducive to an EF-0 tornado with maximum winds speeds of 85 MPH.
Trees were knocked down on power lines. Time estimated by radar.
Trees were knocked down on power lines. Time estimated by radar.
Power poles were snapped for about 1/2 mile along County Road 189 north of County Road 14. Time estimated by radar.
Trees were knocked down along County Road 15. Time estimated by radar.
A power pole was knocked down on County Road 6.
Trees were knocked down near the intersection of County Road 189 and County Road 6.
Trees were knocked down along County Road 15.
A survey team from the National Weather Service and Franklin County Emergency Management conducted a ground survey of damage in Vina. An initially very weak and narrow tornado touched down in the Vina community along Highway 19 just west of Maple Street. Here some limbs were snapped off of a stand of trees on the south side of the road. Additional very minor tree damage was noted south of Highway 19. A tree was uprooted near a home along Cedar street south of Highway 19. Damage was once again noted on the south and west side of the Vina High School. On the south side, a large tree was snapped and a home sustained roof damage. The athletic fields sustained damage to the fences and a baseball dugout was destroyed. Several large unanchored objects here were thrown large distances. The school sustained roof damage in several locations including uplift of the roof on the main building. Windows were also blown out here by the wind with other damage due to the flying debris. Awnings were also destroyed connecting different portions of the school. The tornado was rated EF-0 here with maximum winds of 80 mph due to the damage to the roof in several different locations. The tornado lifted up and blew away shingles on another building here before lifting in the wooded area east-northeast of the school.
Trees were knocked down on power lines in the Colbert Heights area. Time estimated by radar.
Three large trees and one smaller tree were uprooted. Time estimated by radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alabama in 2016Every state in 2016This day in weather historyThe tornado archive for Alabama, 2016Warnings in Alabama, December 2016
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: 670758, 666048, 670759, 670760, 670761, 670762, 670763, 670764, 670765, 666049, 670766, 670757.