By Kate Bilo

PHILADELPHIA (CBS) — You know how the weather in Seattle, and really all of the Pacific Northwest, is famously grey and dreary? Well, it’s all due to the prevailing wind in our latitude. Winds normally blow from west to east, meaning that the Pacific Coast has a persistent flow coming right off the chilly Pacific Ocean. That marine flow leads to lots of clouds and lots of showers.

Here in the Philadelphia area, that prevailing west wind generally keeps the marine issues at bay. But every once in a while, we get into a spell of persistent winds off the Atlantic Ocean and our weather ends up looking like that of a city like Seattle, London or San Francisco in June — dreary, raw and chilly.

With a coastal low lurking offshore the next few days, we’ll be hit with that persistent east wind. In the city, Wednesday is the worst of it — rain bands will rotate through, meaning we’ll be dealing with periods of rain all day long — and the clouds and chilly marine breeze will keep temperatures in the 50s for highs, marking the coldest day since mid-May.

(Credit: CBS3)

We will still feel impacts of this coastal system Thursday and Friday, though not quite as pronounced. It’ll be cool, and mostly cloudy, but doesn’t look as damp as Wednesday.

Down the shore, the issues will persist all week long. That relentless onshore flow will cause the risk for minor tidal flooding and beach erosion, as well as winds gusting as high as 40 mph.

The coastal low finally loosens its grip and moves away by the weekend, leading to progressively improving conditions.