As August 2025 comes closer to an end, early signals for the upcoming winter are emerging. Insights from Weather With Travis highlight Pacific Ocean and Arctic dynamics that could drive a varied U.S. winter with stormy northern patterns and drier southern trends.
Pacific Ocean and ENSO Trends
The Pacific is in an ENSO-neutral phase, with slight cooling in the eastern regions from upwelling. NOAA data suggests a brief La Niña shift by October, fading back to neutral by mid-winter. This typically means warmer, drier conditions in the South and colder, stormier weather in the northern tier. A weaker La Niña may temper extreme warmth in the South, adding forecast uncertainty.
PDO’s Impact on Winter Weather
The Pacific Decadal Oscillation (PDO) hit near-record lows this summer, signaling cooler waters along North America’s west coast and warmer North Pacific areas. This negative PDO could enhance La Niña effects, potentially bringing stormier conditions to the northern Rockies while keeping southern states drier. This season’s neutral lean might disrupt the intense Pacific jets seen recently.
Arctic Sea Ice and Polar Vortex
Arctic sea ice is lower than last year, with notable coverage north of Siberia. Reduced ice could warm the Arctic, weakening the polar vortex and creating a wavier jet stream. This may trigger significant storms, pushing cold air into North America.
Siberian Snow and Cold Air Buildup
Models predict snow buildup across Siberia starting in September, boosting cold air formation via albedo effects. If the Arctic Ocean stays frozen longer, cold spills could intensify North American winters, especially with a disrupted polar vortex.
Weather With Travis’ Regional Winter Outlook
Weather With Travis suggests expecting more snowstorms along the East Coast, particularly in the Mid-Atlantic and Northeast. The South may see warmer conditions, while the Northern Plains and Upper Midwest could face cold snaps with less moisture. The Pacific Northwest looks active, but the Southwest may see a quieter season without strong moisture flows.
