Issued: 6:59 AM PDT Sunday, March 12, 2023
by Dallas Glass

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

Weather Synopsis

While it's generally dry and clear across the mountains this morning, that will change. A warm front will lift north from Oregon spreading clouds and eventually precipitation across the region. Rain and snow should arrive at Mt Hood, Mt St Helens, and Mt Adams first thing. It will slowly work its way northward eventually reaching areas near and north of I90 in the afternoon. Low level E-SE winds should help turn this moisture into more significant snow showers for areas east of the Cascade crest. 

The bulk of the moisture and warmer temperatures arrive this evening. Snow levels will creep up the hillsides. Even though this isn't a particularly warm storm, these are the highest snow levels we've seen in quite some time. Things get even trickier in the Passes. Easterly flow should help moderate some of the incoming warm air, but unfortunately, the cold air pool east of the Cascades doesn't look very deep. As a result, you should see rain at Snoqualmie Pass and mixed precipitation at Stevens and White Passes. 

Winds and precipitation ramp up in the wee hours of Monday morning as the trailing cold front meanders toward the mountains. As it does so, snow levels quickly fall back below Pass and most trailhead locations. An interesting feature Monday could be a Puget Sound Convergence Zone focussed towards this Mt Baker area. This may bring a band of locally heavy snowfall in that region. 

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
Sunday Increasing clouds with light precipitation developing. Light to moderate S winds.
Sunday Night Rain and snow. Moderate to strong SW winds.
Sunday Increasing clouds with precipitation developing later in the day. SSE winds becoming light to moderate.
Sunday Night Rain and snow could be heavy at times. Moderate to strong and gusty S winds.
Sunday Increasing clouds with precipitation developing in the afternoon. Winds becoming S moderate.
Sunday Night Rain and snow, could be heavy at times. Moderate S winds becoming SW.
Sunday Increasing clouds with rain and snow developing late morning. Heaviest near the southern volcanoes. Light to moderate SE winds.
Sunday Night Rain and snow could be heavy at times, especially near the volcanoes. Moderate SW winds.
Sunday Increasing clouds with precipitation developing late in the day. Light E flow at pass level. SE ridgline winds becoming light to moderate/
Sunday Night Rain and snow. Light to moderate E flow at pass level. Light to moderate S winds becoming SW.
Sunday Increasing clouds with precipitation developing in the afternoon. Light to moderate E flow at pass level. SE rideline winds becoming moderate.
Sunday Night Rain and snow could be occasionally heavy at times. Light E flow at pass level. Moderate SE winds becoming SW.
Sunday Increasing clouds with precipitation developing in the afternoon. Light to moderate SSE winds.
Sunday Night Rain and snow with warming temperatures. Moderate S winds decreasing slightly.
Sunday Increasing clouds with precipitation developing in the afternoon. Light to moderate S winds increasing.
Sunday Night Rain and snow showers. Moderate to strong and gusty SW winds decreasing slightly.
Sunday Increasing clouds with precipitation developing mid morning. S winds becoming moderate.
Sunday Night Rain and snow showers. Moderate to strong and gusty SW winds decreasing slightly.
Sunday Increasing clouds with precipitation developing in the morning. SW winds increasing throughout the day and becoming moderate to strong.
Sunday Night Rain and snow, could be heavy at times. Strong and gusty SW winds increasing overnight.

Precipitation (in)

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

Snow Level (ft)

Sunday Morning* Sunday Afternoon* Sunday Evening* Sunday Night* Monday Morning Monday Afternoon
Olympics 1500' 3500' 4000' 3500' 2000' 1500'
West North 1000' 3000' 3500' 3500' 2500' 2000'
West Central 1000' 3000' 3500' 3500' 3000' 2500'
West South 1500' 4000' 4500' 4500' 3500' 3000'
Stevens Pass 1000' 3000' 3500' 3500' 3000' 2500'
Snoqualmie Pass 1500' 3000' 3500' 4000' 3000' 2500'
East North 500' 2500' 2500' 3000' 3000' 3000'
East Central 1500' 3000' 3000' 3500' 3000' 3000'
East South 2000' 3500' 4500' 4500' 4000' 3500'
Mt. Hood 3000' 4500' 5000' 5000' 4500' 3500'
Olympics Elevation
Sunday Morning* 1500'
Sunday Afternoon* 3500'
Sunday Evening* 4000'
Sunday Night* 3500'
Monday Morning 2000'
Monday Afternoon 1500'
West North Elevation
Sunday Morning* 1000'
Sunday Afternoon* 3000'
Sunday Evening* 3500'
Sunday Night* 3500'
Monday Morning 2500'
Monday Afternoon 2000'
West Central Elevation
Sunday Morning* 1000'
Sunday Afternoon* 3000'
Sunday Evening* 3500'
Sunday Night* 3500'
Monday Morning 3000'
Monday Afternoon 2500'
West South Elevation
Sunday Morning* 1500'
Sunday Afternoon* 4000'
Sunday Evening* 4500'
Sunday Night* 4500'
Monday Morning 3500'
Monday Afternoon 3000'
Stevens Pass Elevation
Sunday Morning* 1000'
Sunday Afternoon* 3000'
Sunday Evening* 3500'
Sunday Night* 3500'
Monday Morning 3000'
Monday Afternoon 2500'
Snoqualmie Pass Elevation
Sunday Morning* 1500'
Sunday Afternoon* 3000'
Sunday Evening* 3500'
Sunday Night* 4000'
Monday Morning 3000'
Monday Afternoon 2500'
East North Elevation
Sunday Morning* 500'
Sunday Afternoon* 2500'
Sunday Evening* 2500'
Sunday Night* 3000'
Monday Morning 3000'
Monday Afternoon 3000'
East Central Elevation
Sunday Morning* 1500'
Sunday Afternoon* 3000'
Sunday Evening* 3000'
Sunday Night* 3500'
Monday Morning 3000'
Monday Afternoon 3000'
East South Elevation
Sunday Morning* 2000'
Sunday Afternoon* 3500'
Sunday Evening* 4500'
Sunday Night* 4500'
Monday Morning 4000'
Monday Afternoon 3500'
Mt. Hood Elevation
Sunday Morning* 3000'
Sunday Afternoon* 4500'
Sunday Evening* 5000'
Sunday Night* 5000'
Monday Morning 4500'
Monday Afternoon 3500'

5000' Temperatures (°F)

Sunday Sunday Night
Max / Min Max / Min
Olympics 34 / 23 32 / 28
West North 35 / 24 34 / 28
West Central 34 / 24 33 / 28
West South 34 / 19 32 / 30
Stevens Pass 31 / 25 31 / 29
Snoqualmie Pass 30 / 24 31 / 27
East North 27 / 17 28 / 24
East Central 32 / 24 34 / 28
East South 30 / 21 34 / 28
Mt. Hood 33 / 23 35 / 31
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday 34 / 23
Sunday Night 32 / 28
West North 5000' Temperature Forecast
(Max / Min)
Sunday 35 / 24
Sunday Night 34 / 28
West Central 5000' Temperature Forecast
(Max / Min)
Sunday 34 / 24
Sunday Night 33 / 28
West South 5000' Temperature Forecast
(Max / Min)
Sunday 34 / 19
Sunday Night 32 / 30
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday 31 / 25
Sunday Night 31 / 29
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday 30 / 24
Sunday Night 31 / 27
East North 5000' Temperature Forecast
(Max / Min)
Sunday 27 / 17
Sunday Night 28 / 24
East Central 5000' Temperature Forecast
(Max / Min)
Sunday 32 / 24
Sunday Night 34 / 28
East South 5000' Temperature Forecast
(Max / Min)
Sunday 30 / 21
Sunday Night 34 / 28
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday 33 / 23
Sunday Night 35 / 31

Ridgeline Winds (mph)

Sunday Morning Sunday Afternoon Sunday Evening Sunday Night
Olympics S 10-20 S 10-20 SW 20-30 SW 20-30
West North SSE 5-15 SSE 10-20 S 20-30 S 20-30
West Central SSE 10-20 S 15-25 S 15-25 SW
West South SE 10-20 SSE 10-20 SW 15-25 SW 15-25
Stevens Pass SE 5-15 SE 10-20 S 10-20 SW 10-20
Snoqualmie Pass SE 10-20 SE 15-25 SE 15-25 SW 15-25
East North SSE 10-20 SSE 10-20 S 15-25 S 10-20
East Central S 10-20 S 15-25 SW 20-30 SW 15-25
East South S 10-20 S 15-25 SW 20-30 SW 15-25
Mt. Hood SW 10-20 SW 20-30 SW 25-35 SW 30-40
Olympics Ridgeline Winds (mph)
Sunday Morning S 10-20
Sunday Afternoon S 10-20
Sunday Evening SW 20-30
Sunday Night SW 20-30
West North Ridgeline Winds (mph)
Sunday Morning SSE 5-15
Sunday Afternoon SSE 10-20
Sunday Evening S 20-30
Sunday Night S 20-30
West Central Ridgeline Winds (mph)
Sunday Morning SSE 10-20
Sunday Afternoon S 15-25
Sunday Evening S 15-25
Sunday Night SW
West South Ridgeline Winds (mph)
Sunday Morning SE 10-20
Sunday Afternoon SSE 10-20
Sunday Evening SW 15-25
Sunday Night SW 15-25
Stevens Pass Ridgeline Winds (mph)
Sunday Morning SE 5-15
Sunday Afternoon SE 10-20
Sunday Evening S 10-20
Sunday Night SW 10-20
Snoqualmie Pass Ridgeline Winds (mph)
Sunday Morning SE 10-20
Sunday Afternoon SE 15-25
Sunday Evening SE 15-25
Sunday Night SW 15-25
East North Ridgeline Winds (mph)
Sunday Morning SSE 10-20
Sunday Afternoon SSE 10-20
Sunday Evening S 15-25
Sunday Night S 10-20
East Central Ridgeline Winds (mph)
Sunday Morning S 10-20
Sunday Afternoon S 15-25
Sunday Evening SW 20-30
Sunday Night SW 15-25
East South Ridgeline Winds (mph)
Sunday Morning S 10-20
Sunday Afternoon S 15-25
Sunday Evening SW 20-30
Sunday Night SW 15-25
Mt. Hood Ridgeline Winds (mph)
Sunday Morning SW 10-20
Sunday Afternoon SW 20-30
Sunday Evening SW 25-35
Sunday Night SW 30-40

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

Previous forecast from Mar 11, 2023

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’.