Extreme winter weather is once again testing the resilience of communities, infrastructure and emergency services across the western and northern United States.
In this post, we unpack the science behind the powerful storms, explain what is driving the damaging winds and blizzard conditions, and explore how this unfolding event is affecting travel, power systems and public safety across several states.
What Is Driving the Extreme Weather Across the West and Northern Plains?
The current disruption stems from a combination of large-scale atmospheric features, including a deep low-pressure system and a sequence of atmospheric rivers impacting the Pacific Northwest and interior West.
These systems are working together to generate high-impact weather over a very large area.
Atmospheric Rivers Targeting Oregon, California and Washington
Atmospheric rivers are long, narrow bands of concentrated moisture in the atmosphere, often described as “rivers in the sky.”
When these moisture plumes are steered into the West Coast, they can produce intense rainfall and heavy mountain snow.
In this event, atmospheric rivers are forecast to strike:
Washington, already recovering from record flooding, now faces additional heavy rain and mountain snow.
This raises the risk of renewed flooding, landslides, and dangerous travel conditions over high passes.
A Deep Cyclone Driving Hurricane-Force Winds
A powerful storm system with a central pressure of 982 millibars developed over the northern Plains—comparable in intensity to a strong North Atlantic winter storm.
Such low pressure creates steep pressure gradients, which in turn drive very high wind speeds.
Wind gusts near 100 mph were reported across western South Dakota, and similar conditions extended into Minnesota and the broader northern Plains.
According to The Weather Channel, more than 160 reports of wind damage have been logged, with some sites in the West recording gusts up to 144 mph.
These winds are strong enough to topple trees, damage structures, overturn high-profile vehicles and significantly disrupt travel.
State-by-State Impacts: Roads, Power and Emergency Measures
The severity and breadth of the storm system have prompted emergency declarations, highway closures, and targeted support for affected residents.
The impacts vary by region but share a common thread: unsafe travel conditions and strained infrastructure.
Washington and Oregon: Emergency Declarations and Travel Disruptions
Washington state remains under an emergency through December 22.
This declaration expands the tools available to state officials, including:
In neighboring Oregon, transportation officials have urged residents to avoid non-essential travel.
With strong winds and heavy precipitation, power outages have compromised traffic signals and camera systems, reducing visibility and situational awareness for drivers.
Multiple state highways have been reported closed due to hazardous conditions, debris and poor visibility.
Northern Rockies and High Plains: Blizzards and Extreme Winds
The same storm system has produced blizzard conditions and severe wind impacts across several interior states.
In Montana, wind gusts up to 100 mph have combined with falling and blowing snow, forcing road closures in exposed areas and mountain passes.
Blizzard conditions significantly reduce visibility, making travel extremely dangerous even for experienced drivers.
Idaho has reported downed trees, damaged power lines and overturned trucks, highlighting the risk to freight transportation and rural communities.
These impacts are consistent with high wind events in complex terrain, where funneling through valleys and over ridges can locally amplify wind speeds.
Colorado, anticipating similar hazards, enacted precautionary road closures as winds climbed above 100 mph in some locations.
These proactive measures aim to reduce the risk of accidents and stranded motorists during peak storm intensity.
Power Outages and Community Response
Extreme winds and heavy precipitation inevitably stress electrical infrastructure.
Falling trees, broken branches and blown debris can easily bring down distribution lines and damage substations, especially when soils are saturated or snow-loaded branches are already under strain.
Widespread Outages and Emergency Support
As of December 18, more than 100,000 customers were without electricity across the affected region.
Extended outages in winter present multiple hazards: loss of heating, limited access to communication networks, and disruptions to traffic and public transit.
To support affected residents, the American Red Cross of Colorado opened charging centers in Lakewood and Evergreen.
These facilities provide a critical lifeline by enabling people to recharge phones, access information, and stay connected with family and emergency services during prolonged power shutoffs.
What This Event Tells Us About Winter Hazards
This multi-state winter weather event underscores how interconnected atmospheric systems can create compound hazards—high winds, blizzard conditions, flooding and power outages—over a vast region.
For scientists and emergency planners, it reinforces the importance of:
Here is the source article for this story: Extreme weather snarls travel in several states