Issued: 1:58 PM PST Sunday, January 10, 2021
by Dallas Glass

Jump to: Weather Forecast I Snow Level I Precipitation I Ridgeline Winds I Extended Weather

Weather Synopsis

Most places will experience the proverbial "calm before the storm" Sunday evening. A few isolated showers could continue to bounce around the region overnight, primarily in the Olympics and locations close to the Canadian border. Everywhere else should see dry weather with increasing clouds and strengthening winds as our next weather system bears down on the Pacific Northwest. 

The first in a series of very wet storms should arrive in the region right around sunrise spreading precipitation from NW to SE. This fast-moving front appears to bring moderate precipitation and strong ridgetop winds across the mountains with modest and short-lived spill over to trailheads further east. Snow levels stay relatively low (2500-3500') through this initial event. 

Just as the first system exits the region Monday afternoon, the jet stream takes aim at Washington and Oregon. Several waves of precipitation fed by a sub-tropical moisture tap line up to impact the mountains. Warmer air, ushered in by the atmospheric river, should send snow levels on a steady climb upward. The question remains, how high will they go? Plenty of uncertainty lingers about the snowline during these storms. Cold air east of the crest eventually scours out causing all locations to experience mild conditions. Heavy precipitation spreads over the mountains Monday night into Tuesday with all areas receiving significant amounts of water. Rain and snow begin to lessen by Tuesday afternoon, but the active weather isn't over as we head into the extended forecast period. 

 

Weather Forecast

Use dropdown to select your zone
Sunday Night Cloudy with isolated showers. Strong SW winds increasing overnight.
Monday Cloudy with rain and snow. Strong SW winds in the morning.

Precipitation (in)

Sunday Night Monday Monday Night Tuesday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge LT 0.25 0.25 - 0.50 1.00 0.50
Mt Baker Ski Area 0.25 - 0.50 0.75 1.00 1.00 - 1.50
Mt. Loop - Barlow Pass LT 0.10 0.50 - 0.75 1.00 1.00
Stevens Pass 0 0.25 - 0.50 0.75 1.00
Snoqualmie Pass 0 0.50 1.00 1.00 - 1.50
Crystal Mt 0 0.25 - 0.50 0.75 -1.00 0.75 -1.00
Paradise 0 0.75 -1.00 1.50 1.50
White Pass 0 0.25 - 0.50 0.75 1.00
Washington Pass LT 0.10 0.25 0.50 0.75 -1.00
Mission Ridge 0 LT 0.10 0.50 0.50
Salmon la Sac - Gallagher Head 0 0.25 - 0.50 0.75 -1.00 1.00
Tieton River - Darland Mt. 0 0.25 0.50 - 0.75 0.75
Mt Hood Meadows 0 0.25 - 0.50 1.00 1.00 - 1.50
Timberline 0 0.25 - 0.50 1.00 1.00 - 1.50
Hurricane Ridge Precipitation (in)
Sunday Night LT 0.25
Monday 0.25 - 0.50
Monday Night 1.00
Tuesday 0.50
Mt Baker Ski Area Precipitation (in)
Sunday Night 0.25 - 0.50
Monday 0.75
Monday Night 1.00
Tuesday 1.00 - 1.50
Mt. Loop - Barlow Pass Precipitation (in)
Sunday Night LT 0.10
Monday 0.50 - 0.75
Monday Night 1.00
Tuesday 1.00
Stevens Pass Precipitation (in)
Sunday Night 0
Monday 0.25 - 0.50
Monday Night 0.75
Tuesday 1.00
Snoqualmie Pass Precipitation (in)
Sunday Night 0
Monday 0.50
Monday Night 1.00
Tuesday 1.00 - 1.50
Crystal Mt Precipitation (in)
Sunday Night 0
Monday 0.25 - 0.50
Monday Night 0.75 -1.00
Tuesday 0.75 -1.00
Paradise Precipitation (in)
Sunday Night 0
Monday 0.75 -1.00
Monday Night 1.50
Tuesday 1.50
White Pass Precipitation (in)
Sunday Night 0
Monday 0.25 - 0.50
Monday Night 0.75
Tuesday 1.00
Washington Pass Precipitation (in)
Sunday Night LT 0.10
Monday 0.25
Monday Night 0.50
Tuesday 0.75 -1.00
Mission Ridge Precipitation (in)
Sunday Night 0
Monday LT 0.10
Monday Night 0.50
Tuesday 0.50
Salmon la Sac - Gallagher Head Precipitation (in)
Sunday Night 0
Monday 0.25 - 0.50
Monday Night 0.75 -1.00
Tuesday 1.00
Tieton River - Darland Mt. Precipitation (in)
Sunday Night 0
Monday 0.25
Monday Night 0.50 - 0.75
Tuesday 0.75
Mt Hood Meadows Precipitation (in)
Sunday Night 0
Monday 0.25 - 0.50
Monday Night 1.00
Tuesday 1.00 - 1.50
Timberline Precipitation (in)
Sunday Night 0
Monday 0.25 - 0.50
Monday Night 1.00
Tuesday 1.00 - 1.50

Snow Level (ft)

Sunday Evening * Sunday Night * Monday Morning * Monday Afternoon * Monday Evening * Monday Night * Tuesday Morning Tuesday Afternoon
Olympics 4000' 4500' 4000' 3500' 4000' 5000' 6000' 4500'
West North 4000' 3500' 3500' 4000' 3000' 3000' 4000' 4500'
West Central 4000' 3500' 3000' 4000' 3500' 3000' 5000' 5500'
West South 4000' 4000' 4000' 4500' 4000' 4500' 6500' 6000'
Stevens Pass 3500' 3000' 2500' 4000' 3500' 3000' 5500' 5500'
Snoqualmie Pass 4000' 3000' 2500' 4000' 3500' 3500' 6000' 6000'
East North 2500' 2000' 2000' 3000' 3000' 2500' 2500' 3500'
East Central 3000' 2500' 2500' 3500' 3000' 3000' 3500' 6000'
East South 4000' 3500' 3500' 4500' 4000' 4000' 6000' 6000'
Mt. Hood 5500' 5500' 4500' 6000' 6000' 7000' 7500' 7500'
Olympics Elevation
Sunday Evening * 4000'
Sunday Night * 4500'
Monday Morning * 4000'
Monday Afternoon * 3500'
Monday Evening * 4000'
Monday Night * 5000'
Tuesday Morning 6000'
Tuesday Afternoon 4500'
West North Elevation
Sunday Evening * 4000'
Sunday Night * 3500'
Monday Morning * 3500'
Monday Afternoon * 4000'
Monday Evening * 3000'
Monday Night * 3000'
Tuesday Morning 4000'
Tuesday Afternoon 4500'
West Central Elevation
Sunday Evening * 4000'
Sunday Night * 3500'
Monday Morning * 3000'
Monday Afternoon * 4000'
Monday Evening * 3500'
Monday Night * 3000'
Tuesday Morning 5000'
Tuesday Afternoon 5500'
West South Elevation
Sunday Evening * 4000'
Sunday Night * 4000'
Monday Morning * 4000'
Monday Afternoon * 4500'
Monday Evening * 4000'
Monday Night * 4500'
Tuesday Morning 6500'
Tuesday Afternoon 6000'
Stevens Pass Elevation
Sunday Evening * 3500'
Sunday Night * 3000'
Monday Morning * 2500'
Monday Afternoon * 4000'
Monday Evening * 3500'
Monday Night * 3000'
Tuesday Morning 5500'
Tuesday Afternoon 5500'
Snoqualmie Pass Elevation
Sunday Evening * 4000'
Sunday Night * 3000'
Monday Morning * 2500'
Monday Afternoon * 4000'
Monday Evening * 3500'
Monday Night * 3500'
Tuesday Morning 6000'
Tuesday Afternoon 6000'
East North Elevation
Sunday Evening * 2500'
Sunday Night * 2000'
Monday Morning * 2000'
Monday Afternoon * 3000'
Monday Evening * 3000'
Monday Night * 2500'
Tuesday Morning 2500'
Tuesday Afternoon 3500'
East Central Elevation
Sunday Evening * 3000'
Sunday Night * 2500'
Monday Morning * 2500'
Monday Afternoon * 3500'
Monday Evening * 3000'
Monday Night * 3000'
Tuesday Morning 3500'
Tuesday Afternoon 6000'
East South Elevation
Sunday Evening * 4000'
Sunday Night * 3500'
Monday Morning * 3500'
Monday Afternoon * 4500'
Monday Evening * 4000'
Monday Night * 4000'
Tuesday Morning 6000'
Tuesday Afternoon 6000'
Mt. Hood Elevation
Sunday Evening * 5500'
Sunday Night * 5500'
Monday Morning * 4500'
Monday Afternoon * 6000'
Monday Evening * 6000'
Monday Night * 7000'
Tuesday Morning 7500'
Tuesday Afternoon 7500'

5000' Temperatures (°F)

Sunday Night Monday
Max / Min Max / Min
Olympics 32 / 29 31 / 30
West North 30 / 30 31 / 29
West Central 30 / 29 32 / 28
West South 34 / 31 33 / 32
Stevens Pass 29 / 25 32 / 25
Snoqualmie Pass 30 / 26 32 / 27
East North 26 / 24 32 / 24
East Central 29 / 26 32 / 27
East South 31 / 27 34 / 28
Mt. Hood 34 / 31 35 / 32
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday 4pm - 4am 32 / 29
Monday 4am - 4pm 31 / 30
West North 5000' Temperature Forecast
(Max / Min)
Sunday 4pm - 4am 30 / 30
Monday 4am - 4pm 31 / 29
West Central 5000' Temperature Forecast
(Max / Min)
Sunday 4pm - 4am 30 / 29
Monday 4am - 4pm 32 / 28
West South 5000' Temperature Forecast
(Max / Min)
Sunday 4pm - 4am 34 / 31
Monday 4am - 4pm 33 / 32
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday 4pm - 4am 29 / 25
Monday 4am - 4pm 32 / 25
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday 4pm - 4am 30 / 26
Monday 4am - 4pm 32 / 27
East North 5000' Temperature Forecast
(Max / Min)
Sunday 4pm - 4am 26 / 24
Monday 4am - 4pm 32 / 24
East Central 5000' Temperature Forecast
(Max / Min)
Sunday 4pm - 4am 29 / 26
Monday 4am - 4pm 32 / 27
East South 5000' Temperature Forecast
(Max / Min)
Sunday 4pm - 4am 31 / 27
Monday 4am - 4pm 34 / 28
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday 4pm - 4am 34 / 31
Monday 4am - 4pm 35 / 32

Ridgeline Winds (mph)

Sunday Evening Sunday Night Monday Morning Monday Afternoon
Olympics SSW 30-40 SW 40-55 SW 40-55 W 20-30
West North S 30-40 S 35-50 S 40-55 W 20-30
West Central SSW 20-30 SSW 25-35 WSW 35-50 W 15-25
West South SW 15-25 SW 20-30 SW 35-50 W 25-35
Stevens Pass S 10-20 SSW 10-20 SW 25-35 W 20-30
Snoqualmie Pass SSW 20-30 SSW 15-25 SW 30-40 W 20-30
East North SW 15-25 SW 15-25 SW 25-35 W 20-30
East Central SW 15-25 SW 25-35 SW 30-40 W 30-40
East South SW 20-30 SW 25-35 WSW 30-40 W 40-55
Mt. Hood SW 15-25 SW 30-40 WSW 35-50 W 40-55
Olympics Ridgeline Winds (mph)
Sunday Evening SSW 30-40
Sunday Night SW 40-55
Monday Morning SW 40-55
Monday Afternoon W 20-30
West North Ridgeline Winds (mph)
Sunday Evening S 30-40
Sunday Night S 35-50
Monday Morning S 40-55
Monday Afternoon W 20-30
West Central Ridgeline Winds (mph)
Sunday Evening SSW 20-30
Sunday Night SSW 25-35
Monday Morning WSW 35-50
Monday Afternoon W 15-25
West South Ridgeline Winds (mph)
Sunday Evening SW 15-25
Sunday Night SW 20-30
Monday Morning SW 35-50
Monday Afternoon W 25-35
Stevens Pass Ridgeline Winds (mph)
Sunday Evening S 10-20
Sunday Night SSW 10-20
Monday Morning SW 25-35
Monday Afternoon W 20-30
Snoqualmie Pass Ridgeline Winds (mph)
Sunday Evening SSW 20-30
Sunday Night SSW 15-25
Monday Morning SW 30-40
Monday Afternoon W 20-30
East North Ridgeline Winds (mph)
Sunday Evening SW 15-25
Sunday Night SW 15-25
Monday Morning SW 25-35
Monday Afternoon W 20-30
East Central Ridgeline Winds (mph)
Sunday Evening SW 15-25
Sunday Night SW 25-35
Monday Morning SW 30-40
Monday Afternoon W 30-40
East South Ridgeline Winds (mph)
Sunday Evening SW 20-30
Sunday Night SW 25-35
Monday Morning WSW 30-40
Monday Afternoon W 40-55
Mt. Hood Ridgeline Winds (mph)
Sunday Evening SW 15-25
Sunday Night SW 30-40
Monday Morning WSW 35-50
Monday Afternoon W 40-55

Extended Weather Synopsis

With an atmospheric river pointed at the Washington/Oregon border, expect relatively warm and wet weather. A developing low pressure rides the jet stream and brings another round of moderate to heavy rain and snow to the mountains Tuesday night into Wednesday. At the moment, this event appears the wettest of all three waves of precipitation. After several days of active weather and a thorough soaking, a high-pressure ridge begins to build over the Pacific Northwest. This ridge should give us a chance to dry out and see a return to sunshine. 

Extended Snow Level (ft)

Tuesday Night * Wednesday Wednesday Night Thursday *
West North 4000' 2500' 1000' 1500'
Snoqualmie Pass 6500' 4000' 2000' 2500'
Mt. Hood 8000' 6000' 3000' 4000'
West North Elevation
Tuesday Night * 4000'
Wednesday 2500'
Wednesday Night 1000'
Thursday * 1500'
Snoqualmie Pass Elevation
Tuesday Night * 6500'
Wednesday 4000'
Wednesday Night 2000'
Thursday * 2500'
Mt. Hood Elevation
Tuesday Night * 8000'
Wednesday 6000'
Wednesday Night 3000'
Thursday * 4000'

Jump to: Weather Forecast I Snow Level I Precipitation I Ridgeline Winds I Extended Weather

Previous forecast from Jan 10, 2021

The NWAC program is administered by the USDA-Forest Service and operates from the National Weather Service Forecast Office in Seattle. NWAC services are made possible by important collaboration and support from a wide variety of federal, state and private cooperators.

The 5000’ temperature forecast does not imply a trend over the 12 hr period and only represents the max and min temperatures within a 12 hr period in the zone. The 6-hr snow level forecast, the forecast discussion, and weather forecast sections may add detail regarding temperature trends.

The snow level forecast represents the general snow level over a 6 hr time period. Freezing levels are forecast when precipitation is not expected.

*Easterly or offshore flow is highlighted with an asterisk when we expect relatively cool east winds in the major Cascade Passes. Easterly flow will often lead to temperature inversions and is a key variable for forecasting precipitation type in the Cascade Passes. Strong easterly flow events can affect terrain on a more regional scale.

Ridgeline winds are the average wind speed and direction over a 6 hr time period.

The wind forecast represents an elevation range instead of a single elevation slice. The elevation range overlaps with the near and above treeline elevation bands in the avalanche forecast and differs per zone.

Wind direction indicates the direction the wind originates or comes from on the 16-point compass rose.

Water Equivalent (WE) is the liquid water equivalent of all precipitation types; rain, snow, ice pellets, etc., forecast to the hundredth of an inch at specific locations. To use WE as a proxy for snowfall amounts, start with a snow to water ratio of 10:1 (10 inches of snow = 1 inch WE). Temperatures at or near freezing will generally have a lower ratio (heavy wet snow) and very cold temperatures can have a much higher ratio (dry fluffy snow).

The label LT, is shorthand for ‘less than’.