Issued: 2:58 PM PDT Sunday, March 26, 2023
by Dennis D'Amico

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

Weather Synopsis

Snow showers are starting to pop up over the mountains this afternoon, driven by daytime heating and a cool unstable air mass overhead. While most showers will be light, we may see locally more moderate showers near the southern volcanoes like Mt Rainier and Mt St Helens. Showers will dissipate overnight and skies will begin to clear in the evening. An upper low dropping south along our coastline will spread some mid and high-level clouds over the Olympics, south Washington Cascades and Mt Hood area later tonight. Clearer conditions will prevail further north.

On Monday, that low pressure system now off the northern Californian coast will deepen and spread increasing high clouds further north. We should see a high overcast in the Mt Hood area, and filtered sunshine for the south Washington Cascades transitioning to mostly sunny skies for the central and especially northern Cascades. There's just enough instability in the north Cascades that we may see an isolated afternoon shower, otherwise we can expect a dry day. The other main story will be increasing E-SE winds over the region. The strongest winds will develop over the Mt Hood area and north to Snoqualmie Pass in the afternoon hours. Afternoon highs will be several degrees warmer on Monday than Sunday.   

On Monday night and Tuesday, light to moderate precipitation from the same system will spread into Mt Hood first on Monday night, and eventually light precipitation in the south Washington Cascades during the day Tuesday. E-SE ridgeline winds will affect all areas during this period and may become extreme for areas like Mt. Hood, Crystal Mt, White Pass and Snoqualmie Pass. On Tuesday, while even the north Cascades should be breezy, they should see more sunshine and warmer temperatures than areas closer to the low and further south. 

258 pm update: fixed typo in the synopsis 

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 Night Mostly cloudy with scattered light snow showers in the early evening, then partly to mostly cloudy overnight.
Monday Partly to mostly sunny with periods of high clouds.
Sunday Night Mostly cloudy with scattered light snow showers in the early evening, then mostly clear.
Monday Mostly sunny with a few high clouds late in the day.
Sunday Night Mostly cloudy with scattered light snow showers in the early evening, then mostly clear.
Monday Mostly sunny. Passing high clouds in the afternoon. Moderate ridgeline winds developing in the afternoon.
Sunday Night Mostly cloudy with scattered light to occasionally moderate snow showers in the early evening, especially Mt Rainier and Mt St Helens. Becoming partly cloudy after midnight.
Monday Mostly sunny in the morning with a few high clouds, becoming partly to mostly cloudy with high clouds and filtered sunshine in the afternoon. Strong ridgeline winds developing in the afternoon.
Sunday Night Mostly cloudy with scattered light snow showers in the early evening, then mostly clear. Light W winds at Pass level and ridgeline becoming light E after midnight.
Monday Mostly sunny. Passing high clouds in the afternoon. Moderate E-SE Pass level and ridgeline winds developing in the afternoon.
Sunday Night Mostly cloudy with scattered light snow showers in the early evening, then partly cloudy. Light W winds at Pass level and ridgeline becoming light E after midnight.
Monday Mostly sunny. Passing high clouds in the afternoon. Moderate to strong E-SE Pass level and ridgeline winds developing in the afternoon.
Sunday Night Partly cloudy with a few isolated snow showers, then mostly clear.
Monday Mostly sunny with a few high clouds late in the day.
Sunday Night Partly cloudy with a few isolated snow showers, then mostly clear.
Monday Mostly sunny. Passing high clouds in the afternoon. Moderate to strong ridgeline winds developing in the afternoon.
Sunday Night Partly cloudy with a few isolated snow showers, then mostly clear.
Monday Mostly sunny in the morning with a few high clouds, becoming partly to mostly cloudy with high clouds and filtered sunshine in the afternoon. Moderate ridgeline winds developing in the afternoon.
Sunday Night Mostly cloudy with scattered light snow showers in the early evening, then partly cloudy. High clouds increasing late.
Monday Mostly cloudy in the morning with filtered sunshine, becoming overcast in the afternoon. Strong ridgeline winds developing in the afternoon.

Issued: 2:58 PM PDT Sunday, March 26, 2023

Precipitation (in)

Sunday Night Monday Monday Night Tuesday
5 pm - 5 am 5 am - 5 pm 5 pm - 5 am 5 am - 5 pm
Hurricane Ridge LT 0.10 0 0 0
Mt Baker Ski Area LT 0.10 0 0 0
Mt. Loop - Barlow Pass LT 0.10 0 0 0
Stevens Pass LT 0.10 0 0 0
Snoqualmie Pass LT 0.10 0 0 0
Crystal Mt LT 0.10 0 0 LT 0.10
Paradise LT 0.25 0 0 0
White Pass LT 0.10 0 LT 0.10 LT 0.25
Washington Pass LT 0.10 0 0 0
Mission Ridge LT 0.10 0 0 LT 0.10
Salmon la Sac - Gallagher Head LT 0.10 0 0 LT 0.10
Tieton River - Darland Mt. LT 0.10 0 LT 0.10 0.25
Mt Hood Meadows LT 0.10 0 0.25 0.25 - 0.50
Timberline LT 0.10 0 0.25 0.25 - 0.50
Hurricane Ridge Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday 0
Mt Baker Ski Area Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday 0
Mt. Loop - Barlow Pass Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday 0
Stevens Pass Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday 0
Snoqualmie Pass Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday 0
Crystal Mt Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday LT 0.10
Paradise Precipitation (in)
Sunday Night LT 0.25
Monday 0
Monday Night 0
Tuesday 0
White Pass Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night LT 0.10
Tuesday LT 0.25
Washington Pass Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday 0
Mission Ridge Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday LT 0.10
Salmon la Sac - Gallagher Head Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday LT 0.10
Tieton River - Darland Mt. Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night LT 0.10
Tuesday 0.25
Mt Hood Meadows Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0.25
Tuesday 0.25 - 0.50
Timberline Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0.25
Tuesday 0.25 - 0.50

Issued: 2:58 PM PDT Sunday, March 26, 2023

Snow Level (ft)

Sunday Evening Sunday Night Monday Morning* Monday Afternoon* Monday Evening* Monday Night* Tuesday Morning* Tuesday Afternoon*
Olympics 2000' 1500' 2500' 4000' 3500' 3500' 3500' 4500'
West North 2000' 1500' 2500' 5000' 3500' 2500' 4000' 5500'
West Central 2000' 1500' 2500' 4500' 3500' 3000' 4000' 5000'
West South 2000' 1500' 2500' 4500' 3500' 3000' 3500' 4000'
Stevens Pass 2000' 1500' 2500' 4500' 3500' 3000' 4000' 5000'
Snoqualmie Pass 2000' 1500' 2500' 4500' 3500' 3000' 4000' 5000'
East North 2000' 1500' 2500' 5000' 3000' 2000' 4000' 5500'
East Central 2000' 1500' 2500' 4500' 3500' 3000' 4000' 5000'
East South 2000' 1500' 2500' 4500' 3500' 3500' 3500' 4000'
Mt. Hood 2000' 1500' 2500' 5000' 4000' 3000' 3000' 3500'
Olympics Elevation
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning* 2500'
Monday Afternoon* 4000'
Monday Evening* 3500'
Monday Night* 3500'
Tuesday Morning* 3500'
Tuesday Afternoon* 4500'
West North Elevation
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning* 2500'
Monday Afternoon* 5000'
Monday Evening* 3500'
Monday Night* 2500'
Tuesday Morning* 4000'
Tuesday Afternoon* 5500'
West Central Elevation
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning* 2500'
Monday Afternoon* 4500'
Monday Evening* 3500'
Monday Night* 3000'
Tuesday Morning* 4000'
Tuesday Afternoon* 5000'
West South Elevation
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning* 2500'
Monday Afternoon* 4500'
Monday Evening* 3500'
Monday Night* 3000'
Tuesday Morning* 3500'
Tuesday Afternoon* 4000'
Stevens Pass Elevation
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning* 2500'
Monday Afternoon* 4500'
Monday Evening* 3500'
Monday Night* 3000'
Tuesday Morning* 4000'
Tuesday Afternoon* 5000'
Snoqualmie Pass Elevation
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning* 2500'
Monday Afternoon* 4500'
Monday Evening* 3500'
Monday Night* 3000'
Tuesday Morning* 4000'
Tuesday Afternoon* 5000'
East North Elevation
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning* 2500'
Monday Afternoon* 5000'
Monday Evening* 3000'
Monday Night* 2000'
Tuesday Morning* 4000'
Tuesday Afternoon* 5500'
East Central Elevation
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning* 2500'
Monday Afternoon* 4500'
Monday Evening* 3500'
Monday Night* 3000'
Tuesday Morning* 4000'
Tuesday Afternoon* 5000'
East South Elevation
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning* 2500'
Monday Afternoon* 4500'
Monday Evening* 3500'
Monday Night* 3500'
Tuesday Morning* 3500'
Tuesday Afternoon* 4000'
Mt. Hood Elevation
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning* 2500'
Monday Afternoon* 5000'
Monday Evening* 4000'
Monday Night* 3000'
Tuesday Morning* 3000'
Tuesday Afternoon* 3500'

Issued: 2:58 PM PDT Sunday, March 26, 2023

5000' Temperatures (°F)

Sunday Night Monday
Max / Min Max / Min
Olympics 24 / 19 29 / 20
West North 26 / 20 33 / 20
West Central 26 / 21 32 / 21
West South 25 / 19 31 / 20
Stevens Pass 26 / 20 31 / 20
Snoqualmie Pass 25 / 20 30 / 20
East North 27 / 17 32 / 18
East Central 27 / 19 31 / 19
East South 27 / 19 30 / 19
Mt. Hood 25 / 21 32 / 21
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday Night 24 / 19
Monday 29 / 20
West North 5000' Temperature Forecast
(Max / Min)
Sunday Night 26 / 20
Monday 33 / 20
West Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 26 / 21
Monday 32 / 21
West South 5000' Temperature Forecast
(Max / Min)
Sunday Night 25 / 19
Monday 31 / 20
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 26 / 20
Monday 31 / 20
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 25 / 20
Monday 30 / 20
East North 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 17
Monday 32 / 18
East Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 19
Monday 31 / 19
East South 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 19
Monday 30 / 19
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday Night 25 / 21
Monday 32 / 21

Issued: 2:58 PM PDT Sunday, March 26, 2023

Ridgeline Winds (mph)

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

Issued: 2:58 PM PDT Sunday, March 26, 2023

Extended Weather Synopsis

The same low pressure complex should start to pull further south on Wednesday, taking the clouds and showers with it. We should see mostly sunny skies in much of the area, with a slower clearing trend for Mt Hood and the far south Washington Cascades. Temperatures will warm several more degrees on Wednesday. On Thursday, we begin to see a pattern change with onshore flow developing and low-level marine clouds/moisture beginning to work it's way along the west slopes of the Cascades. It should be a benign weather day with slightly cooler conditions on the west-side than east slopes of the Cascades. 

Extended Snow Level (ft)

Tuesday Night Wednesday Wednesday Night Thursday
West North 4500' 6000' 4500' 4000'
Snoqualmie Pass 4000' 5500' 4500' 4000'
Mt. Hood 3500' 4500' 4000' 4000'
West North Elevation
Tuesday Night 4500'
Wednesday 6000'
Wednesday Night 4500'
Thursday 4000'
Snoqualmie Pass Elevation
Tuesday Night 4000'
Wednesday 5500'
Wednesday Night 4500'
Thursday 4000'
Mt. Hood Elevation
Tuesday Night 3500'
Wednesday 4500'
Wednesday Night 4000'
Thursday 4000'

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

Previous forecast from Mar 26, 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’.