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.Winter Storm Finn Spread Snow, Strong Winds Through The Plains, Midwest (RECAP), Weather Underground, January 10, 2024

Impact Across the United States, over 600,000 customers lost power and 7,000 flights were cancelled.Winter’s Fury: Bomb Cyclones Finn and Gerri Impact Millions Nationwide Devastation and Resilience, Tidal Basin Group, January 10, 2024

Western United States Due to the winter storm in the Sierra Nevada, chains were required for driving on I-80 and US 50.Powerful winter storm brought heavy snow to the Sierra, rain in the valley, CBS News, January 6, 2023 I-80 was also briefly closed. In Reno, Nevada, around 27,000 customers briefly lost power.Winter weather batters both US coasts; Sierra snow shuts down I-80; East Coast storm into Monday, AP News, January 6, 2024 Heavy snow also fell in Coconino County, Arizona, with Forest Lakes receiving of snow. Portions of I-40 and SR 89A shut down due to the snow.Sunday storm brings nearly 11 inches of snow to Flagstaff airport, Arizona Daily Sun

On January 7, in Colorado, I-70 was closed from Watkins, Colorado to the Kansas state line due to the storm.I-70 east of Denver closed, Colorado State Patrol: "SE Colorado is closed" as winter storm stifles travel, CBS Colorado, January 8, 2024 High winds were also reported in the region, with winds in Colorado gusted up to , while winds in the state of New Mexico reached . Snowfall totals in the state of Colorado reached up to 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.Kansans warned against travel as snow continues closures of state roadways, WIBW, January 9, 2024 Visibility in Kansas due to the blizzard dropped as low as . Portions of I-80 in Nebraska also closed due to the snowfall.Interstate 80 in central Nebraska shut down due to whiteout conditions, KLKNTV, January 8, 2024 Blizzard conditions also occurred in the Texas Panhandle, where of snow fell in Dalhart and winds gusted up to .Blizzard pummels Texas Panhandle, snarling traffic with inches of snow, Chron, January 9, 2024 Further south, the storm resulted in a leak at NRG Stadium before the 2024 College Football Playoff National Championship.Heavy rains cause a leak in Houston's NRG Stadium roof before CFP national championship game, Houston Chronicle, January 8, 2024

Record snowfall fell in Des Moines on January 9, with of snow, with the event total being . Portions of Iowa recorded of snow.Did Tuesday's snowfall in central Iowa set a record? And how cold will it get this weekend?, Des Moines Register, January 10, 2024 Snow was lighter in the Chicago metropolitan area, with a peak of around ;How much snow did Chicago get? Snow totals so far today from winter storm, CBS Chicago, January 9, 2024 the snowfall resulted in a ground stop at Chicago O'Hare International Airport.More Than 1,000 Flights Are Canceled as Extreme Weather Batters the U.S., New York Times, January 9, 2024 Slushy roads led to two fatalities in the Midwest – one in Wisconsin and one in Michigan.East Coast residents struggle with flooding, power outages after storms ripped across U.S., NY1, January 10, 2024

Northeast

The storm resulted in flooding across the Northeastern US. The Delaware River in Philadelphia exceeded its all time crest record.https://www.foxweather.com/weather-news/power-outages-east-coast-river-flooding-high-wind The severe storms also produced over 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.Parts of the Northeast and South are recovering after a huge, deadly winter storm, NPR, January 10, 2024 Dozens of Amtrak trains were cancelled due to the storm.Amtrak cancellations continue after powerful storm hits the region, NBC Philadelphia, January 9, 2024 An evacuation order was briefly issued along the Yantic River in Norwich, Connecticut due to a partial dam failure from the heavy rain.Evacuation order lifted along Yantic River in Norwich, Bozrah after inspection of leaking dam, Storm Team 4 NY, January 10, 2024 The National Park Service shut down parts of Fire Island National Seashore due to flooding.Storm Damage Closes Three Boardwalks At National Park On Fire Island, Patch, January 11, 2024 Flooding also resulted in Lodi Public Schools canceling school on January 10.Winter Storm Updates: Tri-State copes with damage, severe flooding in parts, ABC7NY, January 10, 2024 At the Blue Hill Observatory, of rain fell, of which occurred in a single hour. High winds also affected the Northeast, with a peak gust of at Isle au Haut, Maine. Parts of Acadia National Park closed due to the storm, and the park suffered heavy damage.Acadia National Park suffers significant damage from storm, Fox23Maine, January 11, 2024 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 in Dunkirk and 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 9, 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.Deadly storms sweep across South with extensive tornado damage, Fox Weather, January 9, 2024 The tornado outbreak led to a ground stops at Orlando International Airport.

Confirmed tornadoes

January 8 event + List of confirmed tornadoes – Monday, January 8, 2024EF#LocationCounty / ParishStateStart Coord.Time (UTC)Path lengthMax width EF0SupremeAssumptionLA21:42–21:43A brief high-end EF0 tornado caused damage in Supreme. A poorly-anchored and frail mobile home was tossed into a fire station building and a few other mobile homes had their roofs damaged. Tree and power pole damage also occurred. EF0NW of AgricolaGeorgeMS01:25–01:27 A weak tornado moved across open fields, uprooting some small softwood trees. EF0SW of LucedaleGeorgeMS01:31–01:32 A frame home and mobile home sustained minor damage from a brief tornado.

January 9 event