Update: Significant Storm Impacting the Pacific Northwest

No FastCast tonight...storm update below!

A plethora of weather impacts are expected and ongoing across the Northwest tonight. 

Let's start with wind. Winds are increasing across the region as of 8 PM Monday. Let's take a look at the NAM high-resolution forecast for winds Monday night.

According to the NAM, expect gusts of 35-45 mph for the lowlands. Eastern Washington will gust 45-55 mph, except 55-65 mph south of I-90 and on the immediate East Slopes and foothills. A strong westerly wind surge is expected down the Strait of Juan de Fuca, with peak gusts of 50-65 mph along the Strait, Whidbey Island, and the Admiralty Inlet area.

Next, let's look at the HRRR forecast for wind gusts late Monday night.

The HRRR forecast shows peak gusts of 35-45 mph around the lowlands and 45-55 mph across Eastern Washington. The HRRR shows strong westerly winds down the Strait gusting 45-55 mph, including near Everett and Mukiltieo. The HRRR shows gusts up to 55-60 mph on Whidbey and Camano Islands.

Expect potential tree damage and isolated power outages across the lowlands. Wind impacts are most likely near the westerly wind surge along the Strait, Whidbey and Camano Islands, and the Admiralty Inlet area.

Now to the snow...Heavy mountain snow is expected through late Tuesday, with impacts expected on the passes. Below is the NAM high-resolution forecast for snow through Wednesday night.

The NAM shows 12-18 inches at Snoqualmie Pass and 18-30 inches at Stevens Pass. It also shows light snow in the lowlands (trace to 1") from Seattle north to Skagit County, 1-2" from Chehalis south into Oregon, and a trace to 6+" in Eastern Washington.

Next, the HRRR forecast, also showing snow through 

The HRRR shows 12-18" at Snoqualmie and 18-24" at Stevens. The HRRR is more aggressive with lowland snow, showing a trace to 3" for most lowland areas from BC to the Willamette Valley (this is an outlier).

Finally, the UW WRF high-resolution forecast through Wednesday night.

The UW forecast shows 12-18" at Snoqualmie and 18-24" at Stevens, with 0.5-3" in the lowlands from Skagit County southward. This lowland snow solution is also an outlier. 

Expect impacts over the mountain passes through early Wednesday, with heavy snow at times and possible blowing snow. Lowland snow is possible in residual showers from Tuesday evening through late Wednesday. Stay tuned for more information in coming blogs.

Finally, a quick update on the incoming cold weather. From Tuesday evening through Wednesday morning, winds will shift from southerly to northerly, bringing in arctic air and frigid wind chills across the state. Then, winds will likely turn easterly, accelerating gap winds across the foothills and Central Sound by Thursday morning.

Below is the European model forecast for wind chills at 7 AM Thursday.

This is a good representation of the upcoming morning wind chills. Expect wind chills to drop into the low to mid teens for the entirety of Western Washington, with isolated readings in the single digits, most likely near the foothills and Whatcom County. 

Finally, a brief look at expected low temperatures on Thursday morning, from the European model.

Expect lows in Western Washington to be in the low to mid 20s, with outlying areas reaching the upper teens. Eastern Washington will be frigid, with lows in the low single digits to mid teens, with mountainous areas and NE WA dropping below zero.

Stay tuned for updates as this active weather continues!