Significant Rain Ahead as Active Weather Pattern Begins

 FastCast—Wednesday, Oct. 20 to Friday, Oct. 22:

We are entering quite a rainy stretch in Western Washington. A front moving through on Wednesday will bring 0.1-0.3” of rain and winds gusting up to 35 mph. Thursday will be an interesting day as temperatures rise into the mid-upper 60s before rain (heavy at times) moves in by late evening, totaling 0.5-1 inch by Friday morning. Also on Thursday, expect easterly gap winds up to 25 mph in the lowlands and up to 40 mph in the favored foothill locations (North Bend & Enumclaw areas) due to a massive storm offshore drawing winds out of the gaps. On Friday, expect post-frontal showers totaling up to 0.3”. Stay tuned as more Pacific storm systems come rolling in through the weekend and next week. Details are evolving and uncertainty is still high.

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Continue reading the full blog below!

Active weather is ahead for the Pacific Northwest! Due to a strong & persistent trough offshore, multiple Pacific storm systems will impact Western Washington through at least the next week.

The first frontal system will reach the area by Wednesday morning. Below is the UW forecast for rain through 5 PM Wednesday.

Expect 0.1-0.3 inches of rain in most locations, and up to 0.5” in isolated locations by Wednesday evening. More rain is possible (1-2”) on the coast and in the mountains.

We will also have some breezy conditions on Wednesday, with gusts up to 35 mph possible. Below are 5 forecasts from the Windy app for Federal Way.

Expect winds gusting 20-35 mph starting midmorning Wednesday. Winds will diminish and slowly turn easterly by Wednesday evening.

The next system begins to impact the area by Thursday. This will be a trailing front from a massive low pressure system offshore. Read this recent post from Cliff Mass to learn more about this extraordinary storm offshore.

This storm, although hundreds of miles offshore, will draw easterly winds out of the Cascade foothill gaps, bringing 30-40 mph gusts to favored foothill locations (Enumclaw & North Bend areas) on Thursday. Other areas will see easterly gusts up to 30 mph.

Ahead of Thursday’s front, temperatures will rise to the mid-upper 60s across the area. Then, by Thursday evening, the next round of rain moves in. Below is the UW forecast from 5 PM Thursday to 5 PM Friday.

Expect heavy rain at times Thursday evening into early Friday morning, totaling 0.5-0.75” around the metro area, and up to 0.75-1” between Federal Way and Lynnwood.

Below is the 5-day forecast for Federal Way from Weather Underground.

Conclusion: it’ll be rainy. Expect rain or showers each day for the rest of the week. Highs will be in the upper 50s each day except Wednesday and Thursday (60s), with lows in the upper 40s to low 50s.

Stay tuned because the active weather doesn’t stop on Friday. Rain continues through next week, with around 3.6” of rain possible by next Thursday.