Marine Clouds Blanket Pacific Northwest
• A picturesque layer of morning clouds, driven by cool marine air from the Pacific Ocean, covered western Washington and Oregon on September 19,
• According to NASA's Earth Observatory, low-lying stratus clouds and fog extended inland to the Cascade foothills, while taller mountain ranges like the Olympic Mountains and Oregon Coast Range appeared as islands above the cloud layer. The MODIS instrument on NASA’s Terra satellite captured the extent of this cloudy phenomenon at 10:45 a.m. Pacific Time (17:45 UTC). Offshore, abundant clouds were visible over the Pacific, while smoke from wildfires filled valleys in the North Cascades. The cloudy conditions were caused by a temperature inversion, where moist air near the surface cooled enough to condense into clouds.
Impact & Risks
The marine stratus clouds brought cooler temperatures to coastal areas compared to inland regions. Foggy conditions were reported in some areas where clouds extended to the ground, potentially impacting visibility for drivers and outdoor activities. Smoke from wildfires in the North Cascades added to the atmospheric complexity, posing air quality concerns for nearby communities. However, the clouds also provided relief from heat in coastal regions, creating a stark contrast to warmer inland temperatures.
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