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.

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.^[2] 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 effect 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.^[3] 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.^[4]

Across the United States, over 600,000 customers lost power and 7,000 flights were cancelled.^[5]

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.^[27]

• List of North American tornadoes and tornado outbreaks
• Weather of 2024
• List of United States tornadoes from January to March 2024