Issued: 6:51 AM PST Monday, December 13, 2021
by Dallas Glass

Jump to: Weather Forecast I Precipitation I Snow Level I 5000' Temps I Ridgeline Winds I

Weather Synopsis

Snow showers continue across the region this morning as a weak front lifts northward. Easterly winds and plenty of moisture in the atmosphere should allow the heaviest showers to pile up along the eastern slopes of the Cascades in locations like Salmon la Sac, Mission Ridge, Washington Pass, and Mt Hood. With temperatures across the region in the low 20s, these modest water amounts could turn into several inches of snow. Moderate to locally strong east winds will continue to affect areas along the spine of the Cascades. By mid-afternoon, showers and winds speeds should decrease slightly allowing for most mountain locations to get a break from the action. 

The low pressure responsible for our recent snow will slowly meander its way inland starting Monday night into Tuesday. As it does so, it will reinvigorate snow showers particularly for Hurricane Ridge, Mt Baker, and Paradise. Look for winds to shift to the SW and increase Tuesday as the Low passes over western Washington. A weak Puget Sound Convergence Zone could focus shower activity at areas near the Mountain Loop Highway and Stevens Pass Tuesday afternoon and evening. While this isn't a particularly impressive storm, cold temperatures and near-constant showers should keep our trailheads coated in fresh snow. 

Weather Forecast

Olympics
West North
West Central
West South
Stevens Pass
Snoqualmie Pass
East North
East Central
East South
Mt. Hood
Use dropdown to select your zone
Monday Snow showers in the early morning should decrease by mid-day. Strong S winds decrease and turn E in the afternoon.
Monday Night Snow showers, occasionally moderate. Light winds.
Monday Snow showers. Winds becoming light and E.
Monday Night Snow showers, occasionally moderate. Winds becoming moderate to strong SSW.
Monday Snow showers. E winds strongest along the Cascade Crest.
Monday Night Light snow showers, moderate at times. Winds becoming moderate SSW.
Monday Light to occasionally moderate snow showers. Moderate SE winds. Stronger E winds in locations on the crest such as Crystal Mt.
Monday Night Snow showers, heaviest near Mt Rainier. Winds becoming SW moderate to strong.
Monday Snow showers, heaviest east of the Pass. Light SE winds.
Monday Night Snow showers. Winds becoming moderate WSW.
Monday Snow showers, heaviest east of the Pass. Light to moderate SE winds.
Monday Night Snow showers. Winds becoming moderate WSW.
Monday Snow showers, moderate at times. Light to moderate SE winds.
Monday Night Light snow showers. Moderate SE winds decreasing slightly overnight and turning WSW.
Monday Snow showers, heaviest near Mission Ridge and Salmon la Sac. Moderate SSE winds increasing slightly in the afternoon.
Monday Night Snow showers mainly near the Cascade Crest. Moderate to strong SW winds.
Monday Snow showers, heaviest near highway 410. Mostly light S winds.
Monday Night Isolated snow showers, mainly near the Cascade Crest. Moderate to strong winds, SSW becoming W.
Monday Light to moderate snow. Moderate SW winds increasing slightly in the afternoon.
Monday Night Snow showers. Moderate to strong W winds increasing overnight.

Precipitation (in)

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

Snow Level (ft)

Monday Morning* Monday Afternoon* Monday Evening* Monday Night Tuesday Morning Tuesday Afternoon
Olympics 1500' 2000' 2000' 1000' 1000' 1000'
West North 1500' 2000' 2000' 1000' 500' 1000'
West Central 1500' 2500' 2000' 1000' 500' 1000'
West South 2000' 2500' 2000' 1000' 500' 1000'
Stevens Pass 1500' 2500' 2000' 1000' 500' 1000'
Snoqualmie Pass 1500' 2500' 2000' 1000' 500' 1000'
East North 1000' 2000' 1500' 1000' 500' 500'
East Central 1500' 2500' 2000' 1000' 500' 1000'
East South 2000' 2500' 2000' 1000' 500' 1000'
Mt. Hood 2500' 2500' 2000' 1000' 500' 1000'
Olympics Elevation
Monday Morning* 1500'
Monday Afternoon* 2000'
Monday Evening* 2000'
Monday Night 1000'
Tuesday Morning 1000'
Tuesday Afternoon 1000'
West North Elevation
Monday Morning* 1500'
Monday Afternoon* 2000'
Monday Evening* 2000'
Monday Night 1000'
Tuesday Morning 500'
Tuesday Afternoon 1000'
West Central Elevation
Monday Morning* 1500'
Monday Afternoon* 2500'
Monday Evening* 2000'
Monday Night 1000'
Tuesday Morning 500'
Tuesday Afternoon 1000'
West South Elevation
Monday Morning* 2000'
Monday Afternoon* 2500'
Monday Evening* 2000'
Monday Night 1000'
Tuesday Morning 500'
Tuesday Afternoon 1000'
Stevens Pass Elevation
Monday Morning* 1500'
Monday Afternoon* 2500'
Monday Evening* 2000'
Monday Night 1000'
Tuesday Morning 500'
Tuesday Afternoon 1000'
Snoqualmie Pass Elevation
Monday Morning* 1500'
Monday Afternoon* 2500'
Monday Evening* 2000'
Monday Night 1000'
Tuesday Morning 500'
Tuesday Afternoon 1000'
East North Elevation
Monday Morning* 1000'
Monday Afternoon* 2000'
Monday Evening* 1500'
Monday Night 1000'
Tuesday Morning 500'
Tuesday Afternoon 500'
East Central Elevation
Monday Morning* 1500'
Monday Afternoon* 2500'
Monday Evening* 2000'
Monday Night 1000'
Tuesday Morning 500'
Tuesday Afternoon 1000'
East South Elevation
Monday Morning* 2000'
Monday Afternoon* 2500'
Monday Evening* 2000'
Monday Night 1000'
Tuesday Morning 500'
Tuesday Afternoon 1000'
Mt. Hood Elevation
Monday Morning* 2500'
Monday Afternoon* 2500'
Monday Evening* 2000'
Monday Night 1000'
Tuesday Morning 500'
Tuesday Afternoon 1000'

5000' Temperatures (°F)

Monday Monday Night
Max / Min Max / Min
Olympics 23 / 19 20 / 13
West North 26 / 21 24 / 18
West Central 26 / 20 24 / 16
West South 27 / 21 25 / 15
Stevens Pass 25 / 21 25 / 12
Snoqualmie Pass 25 / 21 25 / 15
East North 23 / 18 25 / 16
East Central 25 / 21 25 / 11
East South 25 / 21 25 / 14
Mt. Hood 28 / 22 24 / 12
Olympics 5000' Temperature Forecast
(Max / Min)
Monday 23 / 19
Monday Night 20 / 13
West North 5000' Temperature Forecast
(Max / Min)
Monday 26 / 21
Monday Night 24 / 18
West Central 5000' Temperature Forecast
(Max / Min)
Monday 26 / 20
Monday Night 24 / 16
West South 5000' Temperature Forecast
(Max / Min)
Monday 27 / 21
Monday Night 25 / 15
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday 25 / 21
Monday Night 25 / 12
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday 25 / 21
Monday Night 25 / 15
East North 5000' Temperature Forecast
(Max / Min)
Monday 23 / 18
Monday Night 25 / 16
East Central 5000' Temperature Forecast
(Max / Min)
Monday 25 / 21
Monday Night 25 / 11
East South 5000' Temperature Forecast
(Max / Min)
Monday 25 / 21
Monday Night 25 / 14
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday 28 / 22
Monday Night 24 / 12

Ridgeline Winds (mph)

Monday Morning Monday Afternoon Monday Evening Monday Night
Olympics S 15-25 E 0-10 VAR 0-10 SW 10-20
West North SE 10-20 E 5-15 SE 10-20 SSW 20-30
West Central SE 10-20 E 10-20 SE 10-20 SSW 15-25
West South SE 10-20 ESE 5-15 SSW 15-25 SW 20-30
Stevens Pass SSE 5-15 ESE 5-15 SSE 10-20 WSW 10-20
Snoqualmie Pass SSE 10-20 ESE 10-20 SSE 10-20 WSW 15-25
East North SE 10-20 ESE 5-15 SE 15-25 WSW 10-20
East Central SSE 10-20 SSE 15-25 SSW 20-30 WSW 20-30
East South S 5-15 SSE 5-15 SSW 20-30 W 20-30
Mt. Hood SSW 10-20 SW 15-25 WSW 20-30 W 25-35
Olympics Ridgeline Winds (mph)
Monday Morning S 15-25
Monday Afternoon E 0-10
Monday Evening VAR 0-10
Monday Night SW 10-20
West North Ridgeline Winds (mph)
Monday Morning SE 10-20
Monday Afternoon E 5-15
Monday Evening SE 10-20
Monday Night SSW 20-30
West Central Ridgeline Winds (mph)
Monday Morning SE 10-20
Monday Afternoon E 10-20
Monday Evening SE 10-20
Monday Night SSW 15-25
West South Ridgeline Winds (mph)
Monday Morning SE 10-20
Monday Afternoon ESE 5-15
Monday Evening SSW 15-25
Monday Night SW 20-30
Stevens Pass Ridgeline Winds (mph)
Monday Morning SSE 5-15
Monday Afternoon ESE 5-15
Monday Evening SSE 10-20
Monday Night WSW 10-20
Snoqualmie Pass Ridgeline Winds (mph)
Monday Morning SSE 10-20
Monday Afternoon ESE 10-20
Monday Evening SSE 10-20
Monday Night WSW 15-25
East North Ridgeline Winds (mph)
Monday Morning SE 10-20
Monday Afternoon ESE 5-15
Monday Evening SE 15-25
Monday Night WSW 10-20
East Central Ridgeline Winds (mph)
Monday Morning SSE 10-20
Monday Afternoon SSE 15-25
Monday Evening SSW 20-30
Monday Night WSW 20-30
East South Ridgeline Winds (mph)
Monday Morning S 5-15
Monday Afternoon SSE 5-15
Monday Evening SSW 20-30
Monday Night W 20-30
Mt. Hood Ridgeline Winds (mph)
Monday Morning SSW 10-20
Monday Afternoon SW 15-25
Monday Evening WSW 20-30
Monday Night W 25-35

Jump to: Weather Forecast I Precipitation I Snow Level I 5000' Temps I Ridgeline Winds I

Previous forecast from Dec 12, 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’.