Incoming arctic chill to the U.S. for the middle third of January while the deep freeze is already across Europe likely enhanced by expanding snow cover the next 2 weeks. A wetter pattern change for Brazil in early January reverses drier (again) in the medium-range.

January 2024 looks like a snowy and cold month across the U.S. However, December 2023 produced the second lowest North America snow cover in the 1966-2023 climatology. The least snowy December was in 1980 which was a brutally cold month across Canada and the Northeast U.S. but moisture starved limiting snowfall.

The extreme cold of the “Uri” arctic outbreak centered on Feb. 12-18, 2021, yielded 272 U.S. gas population weight HDD which was about 80 HDD colder than the 30-year normal and 84 HDD colder than the 10-year normal. The preliminary estimate of U.S. gas population weight HDD is in the 234-244 range for the Jan. 11-17, 2024, cold outbreak.

The 12Z GFS piles snow via 4 storms (three are pictured) across the Northeast, Midwest, and South-central U.S. The snow in the East should encourage colder weather. Consequently, the warmer East U.S. midday 12Z GFS may be too warm.