A big rainstorm will move into Western Washington on Tuesday and will stick around through Wednesday.

Essentially the next two days will bring a conveyor belt of rain, what's called an 'atmospheric river' to the Northwest, said KING 5 Meteorologist Jeff Renner.

Our Futurecast weather prediction model points to 48-hour rainfall amounts reaching 2-4 in the Puget Sound basin, and up to 6 in the mountains, said Renner.

King County has issued a Stage 2 Flood Alert for the Snoqualmie River.

And the National Weather Service has posted flood watches for Mason, Skagit and Whatcom counties in Western Washington. Those will become effective Tuesday afternoon.

Flood watches are also posted east of the Cascades for Chelan, Okanogan and Douglas counties.

It will likely be wet for Halloween trick or treating in the evening.

By Thursday the front moves east for decreasing showers and maybe a few sunbreaks.

Friday should become partly sunny, but the rain moves back in again this weekend. Highs will be in the mid to upper 50s through the week.

Check the latest traffic conditions anytime with the Seattle Traffic App and weather with the Seattle Weather App.

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