January 8–10, 2024 North American storm complex

A large and robust storm system, unofficially named Winter Storm Finn by The Weather Channel, brought widespread impacts to much of the contiguous United States early in January 2024. In the northern United States, heavy snow, hail, and gusty winds affected areas from the Great Plains to New England. In the southern United States, a widespread tornado outbreak along the Gulf Coast caused two fatalities and numerous injuries.

Meteorological synopsis
On January 2, 2024, meteorologists from the Storm Prediction Center began tracking a large upper-level trough forecast to move across the United States, with multiple embedded shortwave perturbations. By January 4, evidence of strong surface cyclogenesis pointed towards an intensifying and negatively tilted trough in the south, with a strong surface-low response to the north. These elements were conducive to strong thunderstorms across the country, with intensifying winter storm potential across the north and discrete supercell formation in the southeast. By January 5 as forecast, a powerful winter storm formed in the Gulf of Alaska from the trough, which dove southwards through British Columbia and the Western United States. The now mid-latitude cyclone then moved eastwards, bringing blizzard conditions to the Rocky Mountains and Great Plains on January 7. Six states recorded whiteout conditions during this time. The storm continued to intensify and further severe weather in the east was forecast—more specifically, strong shortwaves from the initial trough were predicted to become robust and affect the south-southeast portions of the United States, as well as create wind-threats for the east coast.

During the early morning hours of January 8, a powerful mid-level shortwave trough was observed moving east across the Sangre de Cristo Mountains. This feature initiated blizzard conditions and heavy snow across Southeast Colorado, the Raton Mesa of northeast New Mexico and far western Kansas. As the storm moved east on January 8 and 9th, the cyclone remained negatively tilted, and formed a tornado outbreak in the Deep South, whilst portions of Indiana recorded record low pressure. Strong mid-level to low-level flow contributed to extreme weather, allowing storms to mature at the mesoscale, with strong moisture return near the coast, and CAPE values in excess of 500-1000 j/kg. The strongest tornado from the outbreak formed near the coast of Panama City, FL, moving on shore and producing EF3 damage.

As the storm moved into the Northeastern United States on January 9, heavy rain and flooding occurred, with snow falling in Northern New England. Freezing conditions were reported, as well as extreme wind and snow. The system moved northward into Canada on January 10.

Impact
Across the United States, over 600,000 customers lost power and 7,000 flights were cancelled.

Western United States
Due to the winter storm in the Sierra Nevada, chains were required for driving on I-80 and US 50. I-80 was also briefly closed. In Reno, Nevada, around 27,000 customers briefly lost power. Heavy snow also fell in Coconino County, Arizona, with Forest Lakes receiving 14 in of snow. Portions of I-40 and SR 89A shut down due to the snow.

On January 7, in Colorado, I-70 was closed from Watkins, Colorado to the Kansas state line due to the storm. High winds were also reported in the region, with winds in Colorado gusted up to 80 mph, while winds in the state of New Mexico reached 76 mph. Snowfall totals in the state of Colorado reached up to 21 in in Wolf Creek Pass.

Midwest
As the storm continued on January 8, many highways were closed in Kansas, including significant portions of I-70, K-4, K-149, K-15 and US 56. Visibility in Kansas due to the blizzard dropped as low as 15 ft. Portions of I-80 in Nebraska also closed due to the snowfall. Blizzard conditions also occurred in the Texas Panhandle, where 4 in of snow fell in Dalhart and winds gusted up to 70 mph. Further south, the storm resulted in a leak at NRG Stadium before the 2024 College Football Playoff National Championship.

Record snowfall fell in Des Moines on January 9, with 8.3 in of snow, with the event total being 11.2 in. Portions of Iowa recorded 15 in of snow. Snow was lighter in the Chicago metropolitan area, with a peak of around 3.5 in. Slushy roads led to two fatalities in the Midwest – one in Wisconsin and one in Michigan.

Northeast
The storm resulted in flooding across the Northeastern US. The Delaware River in Philadelphia exceeded its all time crest record. The severe storms also produced over 4 in of rain in spots. The storm resulted in 110,000 customers losing power in New York, 70,000 customers losing power in Pennsylvania, 56,000 customers losing power in New Jersey, and 28,000 customers losing power in Maine. Dozens of Amtrak trains were cancelled due to the storm. An evacuation order was briefly issued along the Yantic River in Norwich, Connecticut due to a partial dam failure from the heavy rain. The National Park Service shut down parts of Fire Island National Seashore due to flooding. Flooding also resulted in Lodi Public Schools canceling school on January 10. High winds also affected the Northeast, with a peak gust of 95 mph at Isle au Haut, Maine. Parts of Acadia National Park closed due to the storm, and the park suffered heavy damage. Reid State Park in Maine was also shut down due to the storm. Western New York was hit hard by high winds, with winds gusting to 74 mph in Dunkirk and 78 mph in Watertown; the National Weather Service's Buffalo office warned in an Area Forecast Discussion that gusts from the southeast descending from Tug Hill could reach "potentially generational" levels.

Tornado outbreak
Severe weather tore through the southeastern United States on January 8 into January 9th, resulting in 4 fatalities, with 2 of them being tornadic: one each in Alabama and North Carolina. Additional non-tornadic fatalities occurred in the states of Alabama and Georgia. The first January EF3 or stronger tornado in Florida history occurred. The tornado outbreak led to a ground stops at Orlando International Airport.

Graceville, Florida/Cottonwood–Gordon, Alabama
This large, long-tracked tornado developed over remote swampland north of Chipley, Florida in Jackson County and moved north-northeastward along Hickshill Road at EF1 intensity, snapping or uprooting trees and damaging an outbuilding. The tornado then turned northeastward, continuing to damage trees along with the roof of a double-wide mobile home along Piano Road. Continuing northeastward, the tornado continued to snap and uprooted trees and damaged another outbuilding. South of Graceville along SR 77, the tornado damaged homes, blew out the windows of a mobile home, heavily damaged or destroyed outbuildings, and snapped or uprooted countless trees. It also destroyed a pair of 90 ft concrete silos along Cliff Road. Southeast of town, more trees were snapped or uprooted and a home along CR 169 suffered considerable roof damage in this area. Another home along Shiloh Church Loop also suffered significant roof damage to the east of Graceville. The tornado then crossed SR 2, snapping or uprooting more trees and causing minor roof damage to another home before moving over open terrain, where little is any damage occurred. Right before crossing the Florida–Alabama state line, the tornado inflicted minor roof damage to a small business along with minor damage to an outbuilding as it crossed US 231.

Continuing northeastward, the tornado then crossed the state line into Houston County, Alabama while still at EF1 intensity. South of Madrid, the tornado struck a large McLane Company warehouse, which had multiple exterior walls blown out. Many trees were snapped or uprooted, and a power pole was damaged. Beyond this point, several houses, mobile homes, and outbuildings had roofing material torn off, a few power poles were snapped, and countless trees were snapped or uprooted along this segment of the path as well. The tornado briefly reached EF2 intensity as it approached Cottonwood, completely destroying a well-anchored mobile home. The tornado then moved directly through Cottonwood, where several homes and businesses had major roof damage, and one business in the downtown area sustained a total collapse of its front masonry wall. A couple of churches also had roof and window damage and a metal building was left with a large dent in it and had wall panels removed. Much of the peak damage in Cottonwood was rated EF1, but a small area of EF2 damage occurred along SR 53, where a two-story house had its roof torn off. Another area of EF2 damage occurred as the tornado left the town when it leveled a cinderblock Moose Lodge building and a third area of EF2 damage occurred from large trees being snapped. The tornado continued northeastward, continuing to snap trees with a mobile home suffering minor damage. The tornado then briefly reached its peak intensity of high-end EF2 along September Road where a double-wide mobile home was leveled, resulting in a fatality. After moving over another area of open terrain, the tornado caused EF1 tree damage along Creek Church Road. A small outbuilding was also knocked over and at least one power pole was snapped. After crossing US 84 at EF0 strength, the tornado caused some additional tree damage. One final area of EF1 damage occurred along Ed Tolar Road, where a home suffered minor roof damage before the tornado dissipated as it reached CR 95 northwest of Gordon.

The tornado traveled 34.76 mi and reached a width of 1000 yd. One person was killed, and five others were injured.