Rainy & Breezy, Heavy Mountain Snow, and High Avalanche Danger

Saturday was breezy with scattered showers and some elusive sunbreaks early on. 

Starting on Sunday, it will get breezy across Western Washington, as seen in the forecast below for Puyallup.

Expect winds gusting 25-40 mph from Sunday morning to Monday night, peaking Sunday night and Monday morning.

Sunday night and Monday morning will also be the time when the heaviest rain moves through Western Washington. The map below shows total rain through 4 AM Tuesday.

Notice the rain shadow (area of less rain accumulation) over North Seattle. This is because of westerly flow. As you can see, there is much more rain on the west slopes of the Olympics, but far less immediately east. That is due to the Olympics blocking the incoming rain and soaking it up on the west slopes. A similar phenomenon is seen in the Cascade foothills.

Expect 0.4-1.2 inches of rain for the Tacoma/Puyallup areas, where the rain shadow effect will not be as prominent.

This system will also bring a lot of mountain snow. Below is accumulated snowfall through 4 AM Tuesday.

Expect some big totals. The UW model above forecasts 1-2 feet at Snoqualmie Pass and a whopping 2-4 feet at Stevens Pass. This heavy snow will create winter driving conditions on the passes. Take caution if you are traveling in the mountains (and skiers...enjoy that snow!!). Avalanche danger is also high. The Northwest Avalanche Center has issued an Avalanche Warning for Sunday (below).

Here is a day-by-day precipitation forecast for Puyallup from Weather Underground. This helps to know exactly when the most rain is expected.

Expect the most rain on Sunday (mainly later in the day) and on Monday.

Return to Rainy Pattern, More Mountain Snow

After cold temperatures and heavy snow, we have warmed up and are returning to a rainy pattern.

Below, in the forecast for Puyallup from Weather Underground, you can see that rain is likely throughout the next week.

Temperatures will be in the upper 30s-low 40s at night, and in the mid 40s-low 50s during the day. 10-day rain accumulation adds up to approximately 2.8 inches.

The UW model below shows expected rain through 4 AM Saturday. 

Expect 0.3-0.65 inches across the lowlands. The heaviest rain is currently expected on Sunday, along with winds possibly gusting 25-40 mph.

Mountain snow is also expected. Below is a map from NWS Seattle showing mountain snow from Thursday morning to Friday afternoon.

The mountain passes have been hit hard with snow recently, resulting in 12-36 hour closures on Snoqualmie and Stevens Passes in the past week. Stay safe if you are traveling over the mountains, with another 8-18 inches of snow likely. 

(Snow can cause lots of travel headaches...Earlier this week, Snoqualmie Pass received 36 inches of snow in 48 hours...resulting in a 24-hour closure.)

Stay tuned! Some active weather is possible on Sunday!

Update: What to Expect in Changeover

Sunday will be an interesting weather day across Puget Sound. 

Let's start with snow. A Winter Weather Advisory is in effect from 12 PM-10 PM, for up to 2 inches of new snow. This is for the Seattle and Tacoma metro areas. View the alert below.

Below is the Winter Weather Advisory for the Cascade foothills, which is in effect until 10 AM Monday. This alert is different because of the potential for colder air and freezing rain in the foothills.

Up to 0.1-0.2 inches of ice is possible from North Bend to Enumclaw.

Let's time the changeover: (most likely)

Sunday morning-afternoon: Snow, accumulating 1-3 inches

Sunday evening-Monday morning: changeover, snow to rain, chance of freezing rain

Monday afternoon: Rain likely

That's the most likely scenario. It is possible that snow will linger into Sunday night, or end a bit earlier.

Rain on Monday combined with 6-12 inches of melting snow will prompt the possibility of urban flooding on Monday and Tuesday.

Stay tuned to the Twitter accounts below for updates!

NWS Seattle Twitter

South Central Sound Weather Twitter

Bonney Lake Weather Twitter

Scott Sistek (KOMO) Twitter

Shannon O'Donnell (KOMO) Twitter

Morgan Palmer (KIRO) Twitter

Craig Herrera (KING) Twitter

Road conditions will be quite messy through the next couple days. Expect increasing amounts of slush and ice, especially on side streets. Thankfully, a refreeze isn't likely across the region.