PORTLAND, Ore. (KOIN) — Most of the day Tuesday is dry in Portland except in the early morning and evening. It’s a mostly rainy, gusty week with temperatures ranging from the mid 40s to the mid 50s.

Meanwhile, the Columbia River Gorge may encounter a freezing rain and snow combo Tuesday morning. A winter weather advisory is in effect until 6 a.m. Tuesday for the west end of the Gorge.

An easterly wind stays with us for the first part of the week. Wind becomes much stronger by Wednesday. Coastal areas will encounter the strongest winds Wednesday to Thursday with big waves upwards of 20 feet.

Looking ahead:

Tuesday night to Wednesday: Rapid cyclogenesis aka a bomb cyclone is forecast to give birth between Tuesday and Wednesday out in the Pacific. This rapidly deepening area of low pressure will be responsible for hammering on the west coast with damaging winds and big waves by Wednesday.

The central pressure goes from a 995mb low to a 952mb low in a matter of 24 hours. This development occurs more than a thousand miles offshore from Oregon, northeast of the Hawaiian Islands. It will lose some strength as it arrives closer to the Oregon coast.

The center of the low will be approaching the southern Oregon coast but, as of the 00Z model run, it is projected to remain offshore. The overall path of the deep low slides north parallel to our coast Wednesday. Remember we’re dealing with model data so stay with koin.com and check on changes.

Wednesday night to Thursday: East wind increases with gusts to 45-50 mph for PDX and east metro. The west side of the Gorge gusts to 60+ mph. Snow will impact portions of the Gorge. 

Wednesday to Thursday at the coast: Monster waves are generated this week with a building west swell combined with wind waves. Hundreds of miles away, sea heights are modeled to reach 40-50 ft.

Closer to our coast, about 50-100 miles offshore seas up to 30 ft. or higher are possible. We’ll see evidence of this along the central to southern Oregon coast late Wednesday. At the same time we’ll have easterly winds reaching the coast which could give these waves some nice shape. To reiterate, we are not expecting breakers of 30 ft. to hit the shore — maybe 20 ft. near shore. A lot of the energy dissipates by the time it reaches our coast, but waves will be noticeably big.

The last notable bomb cyclone to impact Oregon was November 25-27, 2019.