What are atmospheric rivers hitting the Pacific Northwest?

Atmospheric rivers are long, narrow regions in the atmosphere that carry large amounts of water vapor, leading to heavy rain and snow.

What are the main concerns for Washington and Oregon from the storms?

The main concerns for Washington and Oregon include significant river flooding and potential landslides due to heavy rainfall.

When will the second storm impact the Pacific Northwest?

The second, more significant storm system is expected to impact the Pacific Northwest on Monday and Tuesday.

Home / Weather / Flooding, Landslides Loom as Storms Hit PNW

Flooding, Landslides Loom as Storms Hit PNW

5 Dec, 2025

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Summary

Atmospheric rivers will bring heavy rain and snow to the Pacific Northwest.
Significant river flooding and landslide risks are expected by meteorologists.
The second storm system on Monday and Tuesday poses the greatest threat.

Flooding, Landslides Loom as Storms Hit PNW

A "series of atmospheric rivers" is set to drench the Pacific Northwest starting Friday, according to the National Weather Service. These phenomena, described as "rivers in the sky," transport significant water vapor and are known for causing heavy snow, rain, and strong winds. Meteorologists are particularly concerned about substantial rainfall, which could lead to considerable flooding of rivers and trigger landslides across Washington and Oregon.

The initial storm will begin saturating the region on Friday, with snow expected in higher elevations. However, the second storm system, predicted to arrive Monday and Tuesday, is anticipated to be the most significant, bringing the most substantial impacts. The National Weather Service issued a hydrologic outlook warning of rising rivers, potential urban flooding, and landslides due to saturated soil conditions.