Potential Regenerating Cold in the Northeast U.S. Early January

Chart of the day: Extended range upper air forecasts return Northeast U.S. cold.

Discussion: Both GFS and ECM regenerate a cold upper trough in the Northeast U.S. to Quebec sector as the middle third of January approaches. The forecast explains why a surge in U.S. heating demand is projected by CFS V2 and ECM for the week of Jan. 3-9.

Medium-range 6-10 Day Forecast Valid December 7-11, 2024 (24-hour change)

Discussion: Western warmth shifts eastward while moderating. The eastern chill abates where 24-hour changes are warmest. Snowfall causes the Western Canada warmth to ease late period.

Medium-range 11-15 Day Forecast Valid December 12-16, 2024 (24-hour change)

Discussion: Marginally warm U.S. pattern although the East is adjusted warmer since yesterday. New cold in Western Canada.

U.S. Medium-range Precipitation Forecast

Discussion: The Canadian prairies turn snowy during the medium range. In the U.S. the west/north Gulf Coast is rainy. Snowfall broadens across the Great Lakes region in the 11-15-day period.

Days 16-20 Extended range Temperature Forecast valid December 17-21, 2024

Discussion: The West Canadian chill during mid-month moderates flowing southward into the Great Plains in the extended range. In the East, a rain to snow storm track as marginally mild temperatures are present near the coast.