Ahead of a strong cold front, a squall line featuring possible severe thunderstorms, a rarity for December, moves from the Northern Mid-Atlantic States early this afternoon across southern New England this evening. Locally heavy rain causing flooding high wind, and severe thunderstorms are possible.

Since late October, reasonable skill scores for week-4 forecasts by ECM have decelerated to near zero while choppy CFS V2 skill scores from late warm season have collapsed to below zero. Recent skill scores collapsed due to the un-forecast cold wave to start December in the East.

Early December 2024 was remarkably cold in the East U.S. The unexpected chill is due to an unusual weather pattern featuring highly amplified trough and ridge features from Northeast Asia to the East Coast of North America while most of Eurasia has a somewhat benign pattern. The leading climate diagnostic supporting the East U.S. chill is a streak of mid-latitude stratospheric warming.

November 2024 soil moisture analysis reveals limited drought areas mostly attached to the south and southeast coast. Wet soils dominate the western half of Australia adding parts of the North Coast and either side of the coastal Queensland/New South Wales border.