Barometric Pressure Forecast for Shoreline, Washington
Barometric pressure forecast for Shoreline, Washington — between Puget Sound and Lake Washington in north King County. See current barometric pressure and what it means for weather-sensitive people.
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Pressure and weather in Shoreline
Shoreline sits on the upland between Puget Sound and the north end of Lake Washington, immediately north of Seattle, and it happens to lie in one of the most distinctive small-scale weather zones in North America. When the flow off the Pacific is from the west or northwest, the Olympic Mountains split the air stream in two. One branch runs down the Strait of Juan de Fuca, the other around the southern end of the range, and the two rejoin over the Sound at roughly this latitude. The resulting Puget Sound convergence zone is a narrow band, often only fifteen kilometres wide, of heavy rain, hail or snow that can sit over Shoreline and Edmonds while Seattle a few miles south stays dry. It forms behind a departing front under rising pressure, which again breaks the usual link between falling pressure and heavy weather. The broader barometric year is dominated by autumn and winter Pacific storms, with atmospheric rivers producing falls of twenty to thirty hPa and sustained rain, and the occasional deep low bringing damaging wind. Summer is the dry season, stable and pleasantly flat under the Pacific High.
What this means for you
The convergence zone sets up under rising pressure, so a recovering barometer here does not mean clearing skies. A barometric pressure forecast tells you about the system; the local geography decides who gets the band.