Lake Effect Storm E Summary 29 December 2025 - 3 January 2026 Maximum Snowfall: Lake Erie: 51.5" (Colden 2.4 ENE) Lake Ontario: 59.0" (Lacona 3.6 SSE) Duration: ~120 Hours Flake Scale: 4 Flakes Overview: The cold and active lake effect snow pattern in mid-December eased for much of the remainder of the month, with a 10 day stretch of mild temperatures and minimal snowfall leading up to and through the Christmas holiday. The pattern quickly amplified across North America on 29 December, with a ridge building into the west and forcing a deep downstream longwave trough over the Great Lakes and New England. A strong mid-level closed low developed over Quebec by 30 December, with this low meandering between Hudson Bay and Quebec through the first several days of the new year. The persistent, deep low situated north of the Great Lakes is a classic synoptic scale pattern for prolific and long-lasting lake effect snow to the lee of the eastern Great Lakes, and that proved to unfold in this event. This lake effect storm lasted a full 5 days, with bands meandering north and south numerous times with changes in boundary layer wind direction. This event produced very heavy snowfall rates of 3 to 5 inches per hour at times during peak band intensity off both Lake Erie and Lake Ontario. The combination of high snowfall rates and 4+ feet of total accumulation resulted in significant impacts to travel in the hardest hit areas. Upstream connections and the very favorable setup overall allowed for deep inland penetration of heavy snow at times, with accumulating snow off Lake Erie extending all the way into Rochester and the Finger Lakes at times. Off Lake Erie: Colder air poured back into the eastern Great Lakes on 29 December. A broad area of light to moderate lake enhanced snow developed across much of Western NY through the morning hours. A more narrow and concentrated band of moderate to heavy lake effect snow developed during the mid afternoon across the heart of the Buffalo Metro area and extending east into Genesee County. A secondary cold front then moved through the eastern Great Lakes during the late afternoon, capturing the band of heavy snow and pushing it rapidly south across the western Southern Tier. Northwest flow became established by early evening on 29 December, with a spray of multiple bands across all of Western NY from Lake Erie and Lake Huron. The west-northwest flow and meandering multiple bands continued through the night of 30 December with accumulations spotty and relatively minor. A mid-level trough and developing surface low crossed the eastern Great Lakes on 31 December, bringing with it deeper moisture and increasing synoptic scale ascent. Boundary layer flow become westerly during the morning, allowing for weak multiple bands to evolve into a single band of heavier snow over northern Chautauqua County and the Boston Hills. This band of snow drifted north to the Buffalo Southtowns by early afternoon, and also began to extend far inland with the increased moisture and support from the clipper system. The single band of lake effect snow broadened out into a wide area of moderate lake enhanced snow through the afternoon and evening across much of Western NY, with an embedded band of heavy snow extending from the Buffalo Southtowns into Genesee County and the west side of Rochester. Snowfall rates become quite intense during this timeframe, with 3 to 5 inch per hour rates in the heaviest portion of the band. The arctic cold front associated with the passing clipper moved across Western NY during the evening of 31 December, forcing the band of heavy snow south into the western Southern Tier where it quickly weakened as boundary layer flow became northwest. Weak multiple bands continued across the Boston Hills and western Southern Tier through New Years Day. Another shortwave moved across the eastern Great Lakes on the night of 1 January, with added moisture and synoptic scale ascent supporting a more organized single band of heavy snow from near Dunkirk into the Boston Hills. This band of heavy snow persisted into the early morning hours of 2 January before boundary layer flow became WNW. Weak multiple bands then persisted through the end of the event across the Boston Hills and western Southern Tier. After all was said and done, this event produced a wide area of 1 to 2 feet of accumulation over the 5 day period from the Buffalo Southtowns and Genesee County southward into the western Southern Tier. 2 to 4 foot totals were common from the Boston Hills to western Wyoming County and the Chautauqua Ridge, with the greatest totals across the Boston Hills where heavy snow persisted the longest. The high snowfall rates and deep snow accumulation resulted in significant impacts to travel, including the New York State Thruway from the Buffalo Southtowns to the Pennsylvania State line, and routes heading south from the Buffalo Metro area into the Boston Hills and Southern Tier. Off Lake Ontario: Colder air arrived east of Lake Ontario during the afternoon of 29 December, with a broad area of light lake enhanced snow developing. A more narrow and focused band of heavy lake effect snow developed by early evening from near Watertown to Fort Drum. This band swept quickly south across the Tug Hill region during the evening with the passage of a secondary cold front, dropping a quick burst of heavy snow along the way. Boundary layer flow become west northwest by late evening, with a band of moderate snow focusing from Wayne County to near Syracuse. Multiple bands of light to moderate snow continued through 30 December on west northwest flow from Wayne County east to Oswego County. Moisture improved and upstream connections developed during the night of 30 December, allowing a single band of heavier lake effect snow to focus on Oswego County. This band become strong by the early morning hours of 31 December, with 3 to 5 inch snowfall rates across central Oswego County. A clipper low and shortwave crossed the eastern Great Lakes on 31 December, bringing increased moisture and synoptic scale ascent to support ongoing heavy lake effect snow. Boundary layer flow backed to the west southwest ahead of the low, carrying a band of heavy lake effect snow north across the Tug Hill Plateau to Watertown and Fort Drum by mid-afternoon, then all the way north to the Thousand Islands region by early evening. The arctic cold front associated with the clipper captured the band of heavy lake effect snow during the late evening of 31 December, with a burst of heavy snow spreading south and east across the entire eastern Lake Ontario region as the clocks rang in the new year. Northwest flow produced a spray of weak multiple bands of snow showers southeast of Lake Ontario from Rochester into the Finger Lakes through much of New Years Day. A slight backing of boundary layer flow to the west then allowed for another single band of heavy snow to develop by late afternoon on 1 January near Oswego, with this band then reaching northern Oswego County by mid evening. Intense lake effect snow pounded northern Oswego County through the overnight hours, with 3 to 5 inch per hour snowfall rates and several feet of accumulation just in this one, 12-hour period. The band of heavy snow moved southwest across Oswego County during the early morning hours of 2 January, producing another round of heavy snow across Oswego and Fulton, as well as adjacent areas of far northern Cayuga County. The band remained in this area through much of the night on 2 January, then drifted back to northern Oswego County and the southern Tug Hill region by the morning of 3 January. Another period of intense 3 to 5 inch per hour snowfall rates pounded the region through much of the day before increasing shear forced the band to move quickly south across Oswego County and weaken during the early evening. This long-lasting event produced a large area of 2 to 3 feet of accumulation across all of Oswego County, northern Cayuga County, and the Tug Hill Plateau. The greatest accumulations of well over 4 feet were focused across northern Oswego and southwest Lewis counties. The high snowfall rates and deep snow accumulation resulted in significant impacts to travel, including the Interstate 81 corridor in northern Oswego County.