Friday Evening Storm Update

Update 9:10 PM: The cold front remains mostly offshore. It is more likely that the front will move through the metro area after 10 PM.

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It has already rained across most of Western Washington today, with the most rain on the coast and north of Everett (0.3-1.2”). The Puget Sound area received 0.01-0.2”, most from Seattle southward.

This morning’s rain has moved into the Cascades, a heavier round of rain is moving in from the coast. Between approximately 9 and 10 PM, an strong cold front will move through Western Washington, followed by more rain. 

At 9 PM, the heavy rain band is heading into the Seattle area, as seen in the UW forecast below.

By 10 PM the cold front will have moved through the eastern parts of the metro area.

This will be an heavy band of rain, also called a NCFR (narrow cold frontal rainband), with 0.25-0.5 inches of rain falling within ~3 hours. Winds will gust 30-40 mph, higher near Puget Sound.

Keep in mind that the threat for tree damage and power outages will be highest during and in the few hours after the frontal passage.

Additionally, there is a potential for urban flooding during frontal passage and through the weekend, especially near clogged storm drains.

There is also a slight chance of thunderstorms as the front moves through. Be prepared for lightning & thunder!

What about rain totals? Below is the UW high-resolution forecast for rain totals through Sunday morning.

It is likely that most of the Puget Sound area to receive 1-2 inches of rain, with amounts varying locally. Much higher amounts are likely in the mountains.

Thunderstorms are still possible as rain becomes more showery on the weekend. Any showers this weekend have a potential to produce thunder, lightning, and potential hail, all the usual threats with post-frontal showers.

In short…an active weekend is in store, starting tonight! Stay updated by clicking the Twitter icon on the right side of the blog. This takes you to my Twitter page.

You can access the latest weather information from the UW forecast models by clicking here and on the right side of the blog.