Barometric Pressure Forecast for Yakima, Washington
Barometric pressure forecast for Yakima, Washington — in the Yakima Valley basin, deep in the Cascade rain shadow. Check current barometric pressure and what it means for weather-sensitive people.
Download Pressure Pal to track barometric pressure and get migraine alerts for Yakima and your area.
Pressure and weather in Yakima
Yakima sits in a broad basin ringed by ridges in the driest part of central Washington, receiving under 200 millimetres of rain a year because the Cascades strip the moisture from every Pacific system before it arrives. The basin shape is what defines the weather year. From November through February cold dense air settles into the valley floor and is capped by warmer air above, creating one of the most persistent inversions in the western United States. During those spells fog or low stratus can hold for a week or more, the air quality declines steadily, and the barometer sits almost motionless. Breaking the inversion takes a system strong enough to mix the valley out, which usually means a vigorous trough crossing the Cascades, and that is when the real pressure changes arrive. Spring and autumn are the most transitional periods, with systems crossing more freely. Summer brings intense dry heat and, increasingly often, wildfire smoke from fires across the interior Northwest, which the same basin geometry traps in exactly the way it traps winter fog.
What this means for you
Yakima's winters are unusually flat on the barometer, but the trapped air under a long inversion affects many weather-sensitive people regardless. Watching the barometric pressure forecast for the system that finally mixes the valley out is often the more useful signal.