Overview
- The National Weather Service has warnings and advisories across New York City, Long Island, Westchester, adjacent New Jersey and Connecticut, and parts of Illinois and Indiana as Arctic air sweeps south.
- New York City shifted from near 50°F in the morning to winterlike conditions by afternoon with northwest wind gusts around 30–40 mph and wind chills near 20°F.
- Over the Great Lakes, very cold air over warmer waters is generating intense lake‑effect snow bands, with the heaviest snowfall southeast of Lakes Erie and Ontario.
- A localized, unusually intense lake‑effect storm hit northern Illinois and the Chicago area early Monday, with some spots topping 11–12 inches and reports of snowfall rates up to 3 inches per hour.
- Chicago saw significant disruption with hundreds of flight cancellations and school closures, while forecasters say the worst of the cold and snow is focused Monday–Tuesday before a gradual moderation midweek.