Cool, Dry, and Mostly Sunny Week Ahead

FastCast—Tuesday, Nov. 14 to Saturday, Nov. 18:

A cool, dry, and mostly sunny week is ahead for the Northwest! With the exception of a weak system on Wednesday, it will be mostly sunny and dry every day through Friday. The next system will arrive late Saturday, likely bringing a round of rain and breezy conditions. Until then, expect mostly sunny skies (except mostly cloudy on Wednesday), with highs only reaching the upper 40s to low 50s. Morning lows will be noticeably colder than previous nights, dropping to the low to mid 30s each morning this week. The main impact will be morning fog, locally dense, and the potential for black ice. Remember to be aware when driving in foggy conditions and always be ready for black ice. The system on Wednesday will bring clouds, but little chance of rain. Light rain (if any) is possible in the lowlands, with a dusting of snow possible in the mountains above 2,000 feet.

(Peak wind gusts from weekend storm at bottom of blog)

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Continue reading the full blog below!

A significant change in the weather…to a chilly and sunny pattern…is ahead. With the exception of mostly cloudy skies with scattered drizzle on Wednesday, mostly sunny conditions are likely through Friday. 

The biggest weather impact to watch for will be morning fog. Some areas of dense fog are possible, especially in the South Sound. Fog is most likely on Thursday and Friday, but is possible any day this week.

Low temperatures will be significantly colder than recent days, so let’s take a look at the forecast, starting with lows on Tuesday morning from the European model.

On Tuesday morning, expect lowland lows in the low to mid 30s, coldest east of I-5 and from Everett northward. The Willamette Valley will drop to the mid to upper 30s, while Eastern WA will cool to the upper 20s to low 30s, except the mid 30s for the southern tier. Mountain towns will drop to the 20s.

Wednesday morning’s lows will be warmer due to the influx of clouds from the weak system.

Notice that Wednesday morning’s lows rise to the mid 30s to low 40s for the lowlands and Eastern Washington, with some isolated spots dropping to around freezing. The Willamette Valley will remain in the low 40s.

However, morning lows plunge by Thursday morning, seen below.

Thursday morning will be significantly colder, with lowland lows in the upper 20s to low 30s, Eastern Washington lows in the mid 20s to low 30s, and Willamette Valley lows in the low to mid 30s. Mountain towns will drop to the low 20s.

Finally, a look at Friday morning’s lows, seen below on the European model.

On Friday morning, lows will again be in the upper 20s to low 30s for most of the lowlands, with all of Eastern Washington in the mid 20s to low 30s. The Willamette Valley will drop to the low to mid 30s again.

One notable difference with this week versus the rest of the month so far is the absence of rain. Below is the European model forecast for rain through Friday night.

Notice that almost all of Western Washington is dry, with only the northern and southern portions of Western WA getting up to 0.1” of rain. Eastern Washington, including the Tri Cities, Spokane, Pullman, and Walla Walla, will get 0.1-0.3” on Wednesday. The Willamette Valley will get 0.1-0.2” as well.

Enjoy the dry week and the mostly sunny conditions!

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Peak Wind Gusts: November 10-11, 2023:

Whidbey Island Naval Air Station: 64 mph

Bellingham Int’l Airport: 64 mph

Camano Island: 58 mph

Hoquiam Airport: 55 mph

Cape Disappointment: 53 mph

Tacoma Narrows Airport: 52 mph

Everett Paine Field: 51 mph

Olympia Airport: 51 mph

Sea-Tac Airport: 41 mph

Shelton Airport: 40 mph

Western Washington Windstorm Update

No FastCast tonight...continue reading the full blog below for a windstorm update (and an updated look at rain and mountain snow forecasts). Heavy rain and strong winds are likely with frontal passage early Saturday morning. There is also a chance of thunderstorms in post-frontal showers on Saturday.

Across Western Washington, expect winds to peak from late Friday night to early Saturday morning.

Let's start with the high-resolution HRRR forecast, showing peak winds during this storm.

This forecast has consistently shown stronger winds than other forecasts, but has been accurate as of 10 PM. This forecast shows 50-60 mph gusts from Everett northward, including gusts near or just over 60 mph near Bellingham. Areas from Everett southward will gust 40-50 mph in this forecast. The coast will gust up to 45-55 mph in this scenario as well. If this forecast verifies as shown above, power outages and tree damage is likely.

Let's compare this to the NAM high-resolution forecast, seen below at 1 AM Saturday.

At 1 AM, the NAM forecast shows gusts of 45-55 mph from Seattle northward. From Seattle south, the NAM shows gusts reaching 40-45 mph around 1 AM, with gusts up to 50 mph on the coast.

Fast forward to 5 AM Saturday, seen below on the NAM forecast.

Around 5 AM, expect gusts in the lowlands to reach 45-50 mph, as frontal passage nears. As with the previous forecast, tree damage and power outages are possible with this storm. Localized gusts over 50 mph are possible in the lowlands.

Finally, let's take a look at the European model forecast for peak wind gusts, showing the entire state.

This forecast is in knots, so actual miles per hour speeds will be stronger. This forecast shows gusts in the lowlands reaching 40-45 mph, with 45-55 mph gusts from Everett northward, but mainly on the water and in western Whatcom County. Eastern Washington will gust 40-50 mph, strongest east of the Tri Cities and around the Spokane area. 

Let's take a look at the rain forecast from the European model, seen below. I've zoomed in these graphics to Western Washington, since Eastern WA won't have much rain (if any).

This forecast, through early Sunday morning, shows 0.7-1" of rain for most of the Puget Sound region, with a rain shadow from Seattle to Everett. The foothills could get 1-1.5" of rain, and parts of the coast will get up to 2", along with the mountains, where up to 3" is possible.

The GFS (American) forecast below shows agreement with the European model.

The GFS shows 0.7-1" for most of the region, with a rain shadow from Whidbey Island to Seattle. The coast and mountains will get 1-3" with this forecast.

Finally, the snow forecast for the mountains, seen below on the European model.

This forecast shows significant snow for higher elevations of the North Cascades, with up to 12-18" for the North Cascades Highway and Mount Baker, along with 6-12" at Paradise. The higher passes (Stevens & White) will get up to 6" of snow, while Snoqualmie Pass will get up to 2". Winter weather impacts will be relegated to areas over 4,000-4,500 feet.

Remember to be prepared for power outages and tree damage with the winds. Charge your devices and be careful out there! 

Next Storm to Bring Strong Winds, Rain, and Mountain Snow

FastCast—Friday, Nov. 10 to Monday, Nov. 13:

After a relatively calm few days and a weakening storm that moved through on Thursday, a stronger storm will impact the Northwest from Friday afternoon through Saturday. The main impact will be strong winds, with a decent round of rain and mountain snow for the higher passes. Winds will likely gust 40-45 mph for most of the lowlands, 45-50 mph on the coast, and 50-55 mph from Everett northward, especially for Island, Whatcom, and San Juan Counties. Isolated gusts of 55-60 mph are possible for those areas. Region-wide, winds will peak from late Friday night through midmorning Saturday. Most of the lowlands will also receive 0.75-1.3” of rain through Sunday morning, most falling from Friday afternoon through Saturday morning. Higher elevations in the mountains, such as Paradise, Chinook Pass, and the North Cascades Highway will receive 6-12” of snow, with isolated higher amounts. Stevens and White Passes could see 0.5-2” of snow, as snow levels will hover around 4,000-4,500 feet. The next system will bring another round of rain and higher mountain snow from Sunday night to Monday. Through Monday, expect lowland highs in the low 50s, with lows in the mid 40s.

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Continue reading the full blog below!

An active couple days is ahead for Western Washington, as a storm approaches the region, with impacts being felt across the region. Let’s take a look at the forecast!

First, the wind forecast. We’ll start with the European model forecast for peak gusts through Saturday night.

This forecast (which is in knots) shows peak gusts from Everett southward reaching 40-45 mph, strongest early Saturday morning. For areas north of Everett, especially Island, San Juan, and western Whatcom Counties, peak gusts will likely reach 45-55 mph. Isolated gusts of 55-60 mph are possible. The coast will gust 45-50 mph. Both the coast and North Sound will have peak winds from late Friday night to early Saturday morning. Additionally, parts of Eastern Washington, mainly from Moses Lake to Spokane, will gust 40-50 mph on Saturday.

Let’s compare this to the NAM high-resolution wind forecast, first showing gusts at 1 AM Saturday.

The NAM shows strong gusts of 40-45 mph for most of the region very early Saturday morning. Whidbey Island, San Juan & Whatcom Counties, and the immediate coastline will gust up to 55 mph. 

Next is the NAM forecast for 6 AM Saturday.

The NAM forecast shows peak winds for the metro area being around sunrise on Saturday, with gusts of 40-45 mph (isolated gusts closer to 50 mph). 

Remember, it is still early in the season, and this weekend’s forecasted winds will likely cause tree damage and some power outages across the region. Trees still have lots of leaves, which will make them more susceptible to damage. Be prepared for winds and monitor the forecast accordingly!

Next, we will take a look at the rain forecast. First, the European model, showing total rain through Sunday morning (most will fall from Friday afternoon through Saturday morning, with some showers through Saturday).

This forecast shows 0.75-1.2” of rain for the lowlands, with a rain shadow over the San Juans. The coast will pick up 1-2.5” (most from Ocean Shores northward), and the mountains will get 1-3” (most in the Olympics & North Cascades). Eastern Washington will stay relatively dry with this system.

Below is the GFS (American) forecast, showing a similar scenario to the European.

The GFS forecast also shows 0.7-1.2” of rain for the lowlands, with 1-2.7” on the coast (most on the North Coast), and 1-4” in the mountains, most in the Olympics and North Cascades. The GFS and European strongly agree that Eastern Washington will remain almost completely dry with this storm.

Finally, we’ll end tonight’s blog with a look at the snow forecast through Sunday morning from the European model.

This forecast shows significant snow for higher elevations in the North Cascades and the higher peaks, with the North Cascades Highway, Mount Baker, and Paradise likely to get 6-12”. The passes will get much less due to snow levels staying around 4,000-4,500 feet during the storm. Expect 0.5-2” at most at the passes.

Stay tuned for a wind update on Friday night!