Issued: 2:32 PM PDT Saturday, March 27, 2021
by Dennis D'Amico

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

Weather Synopsis

A Pacific frontal system bearing down on the region in NW flow will spread increasing clouds over the region tonight with precipitation beginning over the Olympics and north Cascades over midnight. The front will slip south during the day, with precipitation at first holding of for the south and central Cascades during the morning hours. The upper level trough digging behind the frontal system will help it pack a punch - wide spread W-SW extreme winds are expected in the afternoon from north to south across the region.  Snow levels will start in the 3000-4000' range but quickly plummet with the onset of precipitation. Snowfall rates over an inch an hour are possible from the Canadian border to the Mt Loop Hwy in the early afternoon and the central Cascades and Mt Rainier area mid-afternoon.  The front should pass through the Cascades around 3 pm.  A Puget Sound Convergence will likely form in the early evening and target the Hwy 2 corridor.  Mt Hood will see their heaviest precipitation slightly later as the front slides south into the evening.  

Snow levels will drop rapidly with the frontal passage in the afternoon - expect snow levels to fall below 2500' over the west slopes of the Cascades by 5 pm tomorrow. 

Showers will continue Sunday night, easing into Monday morning. We'll be on the backside of the upper trough on Monday, expect cool, cloudy and showery conditions.

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
Saturday Night Cloudy with light rain and snow developing late. Increasing ridgeline winds.
Sunday Moderate rain and snow becoming light to moderate showers late. Strong winds.
Saturday Night Cloudy with light rain and snow developing late after midnight. Increasing ridgeline winds.
Sunday Light to moderate rain and snow becoming moderate to occasionally heavy rain and snow by late morning. Strong winds becoming strong to extreme mid-day.
Saturday Night Cloudy with light rain and snow developing late. Increasing ridgeline winds.
Sunday Light to moderate rain and snow developing in the morning and becoming moderate to occasionally heavy rain and snow around mid-day. Strong winds becoming strong to extreme by the afternoon.
Saturday Night Partly cloudy in the evening becoming cloudy after midnight. Increasing ridgeline winds.
Sunday Light to moderate rain and snow developing late morning and becoming moderate to occasionally heavy rain and snow in the afternoon. Strong winds becoming strong to extreme by the afternoon.
Saturday Night Mostly cloudy in the evening becoming cloudy after midnight. Increasing ridgeline and Pass level west winds.
Sunday Light to moderate rain and snow developing in the morning and becoming moderate to occasionally heavy rain and snow around mid-day. Strong winds at Pass and ridgeline level becoming strong to extreme by the afternoon.
Saturday Night Mostly cloudy in the evening becoming cloudy after midnight. Increasing ridgeline and Pass level west winds.
Sunday Light to moderate rain and snow developing in the morning and becoming moderate to occasionally heavy rain and snow around mid-day. Strong winds at Pass and ridgeline level becoming strong to extreme by the afternoon.
Saturday Night Mostly cloudy in the evening becoming cloudy after midnight. Increasing ridgeline winds.
Sunday Light to moderate rain and snow increasing and becoming moderate in the afternoon. Heaviest precipitation near the Cascade crest. Strong winds becoming strong to extreme by the afternoon.
Saturday Night Partly cloudy in the evening becoming cloudy after midnight. Increasing ridgeline winds.
Sunday Light rain and snow developing in the morning and becoming moderate in the afternoon. Heaviest precipitation near the Cascade crest. Strong winds becoming strong to extreme by the afternoon.
Saturday Night Partly cloudy in the evening becoming cloudy after midnight. Increasing ridgeline winds.
Sunday Light rain and snow developing in the morning and becoming light to moderate in the afternoon. Heaviest precipitation near the Cascade crest. Strong winds becoming strong to extreme by the afternoon.
Saturday Night Partly cloudy in the evening becoming cloudy late. Increasing ridgeline winds.
Sunday Cloudy with light rain and snow developing mid-day, becoming moderate late in the afternoon. Winds increasing and becoming extreme in the afternoon.

Issued: 2:32 PM PDT Saturday, March 27, 2021

Precipitation (in)

Saturday Night Sunday Sunday Night Monday
5 pm - 5 am 5 am - 5 pm 5 pm - 5 am 5 am - 5 pm
Hurricane Ridge LT 0.10 0.50 LT 0.25 0
Mt Baker Ski Area 0.25 1.00 - 1.50 0.25 0
Mt. Loop - Barlow Pass LT 0.10 1.00 0.50 0
Stevens Pass 0 0.50 - 0.75 0.50 LT 0.10
Snoqualmie Pass 0 0.50 - 0.75 0.50 LT 0.10
Crystal Mt 0 0.25 0.25 - 0.50 LT 0.10
Paradise 0 0.50 - 0.75 0.50 LT 0.10
White Pass 0 0.25 - 0.50 0.25 - 0.50 LT 0.10
Washington Pass LT 0.10 0.50 - 0.75 LT 0.25 0
Mission Ridge 0 LT 0.25 LT 0.25 0
Salmon la Sac - Gallagher Head 0 0.25 0.25 - 0.50 LT 0.10
Tieton River - Darland Mt. 0 LT 0.25 0.25 LT 0.10
Mt Hood Meadows 0 LT 0.25 0.75 0.25
Timberline 0 0.25 1.00 0.25 - 0.50
Hurricane Ridge Precipitation (in)
Saturday Night LT 0.10
Sunday 0.50
Sunday Night LT 0.25
Monday 0
Mt Baker Ski Area Precipitation (in)
Saturday Night 0.25
Sunday 1.00 - 1.50
Sunday Night 0.25
Monday 0
Mt. Loop - Barlow Pass Precipitation (in)
Saturday Night LT 0.10
Sunday 1.00
Sunday Night 0.50
Monday 0
Stevens Pass Precipitation (in)
Saturday Night 0
Sunday 0.50 - 0.75
Sunday Night 0.50
Monday LT 0.10
Snoqualmie Pass Precipitation (in)
Saturday Night 0
Sunday 0.50 - 0.75
Sunday Night 0.50
Monday LT 0.10
Crystal Mt Precipitation (in)
Saturday Night 0
Sunday 0.25
Sunday Night 0.25 - 0.50
Monday LT 0.10
Paradise Precipitation (in)
Saturday Night 0
Sunday 0.50 - 0.75
Sunday Night 0.50
Monday LT 0.10
White Pass Precipitation (in)
Saturday Night 0
Sunday 0.25 - 0.50
Sunday Night 0.25 - 0.50
Monday LT 0.10
Washington Pass Precipitation (in)
Saturday Night LT 0.10
Sunday 0.50 - 0.75
Sunday Night LT 0.25
Monday 0
Mission Ridge Precipitation (in)
Saturday Night 0
Sunday LT 0.25
Sunday Night LT 0.25
Monday 0
Salmon la Sac - Gallagher Head Precipitation (in)
Saturday Night 0
Sunday 0.25
Sunday Night 0.25 - 0.50
Monday LT 0.10
Tieton River - Darland Mt. Precipitation (in)
Saturday Night 0
Sunday LT 0.25
Sunday Night 0.25
Monday LT 0.10
Mt Hood Meadows Precipitation (in)
Saturday Night 0
Sunday LT 0.25
Sunday Night 0.75
Monday 0.25
Timberline Precipitation (in)
Saturday Night 0
Sunday 0.25
Sunday Night 1.00
Monday 0.25 - 0.50

Issued: 2:32 PM PDT Saturday, March 27, 2021

Snow Level (ft)

Saturday Evening Saturday Night Sunday Morning Sunday Afternoon Sunday Evening Sunday Night Monday Morning Monday Afternoon
Olympics 6500' 4500' 3500' 2500' 1000' 500' 1500' 3000'
West North 4500' 4000' 3500' 3000' 1000' 500' 1500' 2500'
West Central 4500' 4500' 4000' 3500' 1500' 500' 1500' 3000'
West South 6000' 5000' 5000' 4000' 1500' 500' 1500' 3000'
Stevens Pass 4500' 4500' 4000' 3500' 1500' 500' 1500' 3000'
Snoqualmie Pass 5000' 4500' 4500' 4000' 1500' 500' 1500' 3000'
East North 5000' 4000' 4500' 4000' 1500' 500' 1500' 3500'
East Central 6000' 5000' 5500' 4500' 1500' 500' 1500' 3500'
East South 7000' 6000' 5500' 5000' 1500' 500' 1500' 3500'
Mt. Hood 9000' 8000' 6500' 5500' 1500' 500' 1500' 4000'
Olympics Elevation
Saturday Evening 6500'
Saturday Night 4500'
Sunday Morning 3500'
Sunday Afternoon 2500'
Sunday Evening 1000'
Sunday Night 500'
Monday Morning 1500'
Monday Afternoon 3000'
West North Elevation
Saturday Evening 4500'
Saturday Night 4000'
Sunday Morning 3500'
Sunday Afternoon 3000'
Sunday Evening 1000'
Sunday Night 500'
Monday Morning 1500'
Monday Afternoon 2500'
West Central Elevation
Saturday Evening 4500'
Saturday Night 4500'
Sunday Morning 4000'
Sunday Afternoon 3500'
Sunday Evening 1500'
Sunday Night 500'
Monday Morning 1500'
Monday Afternoon 3000'
West South Elevation
Saturday Evening 6000'
Saturday Night 5000'
Sunday Morning 5000'
Sunday Afternoon 4000'
Sunday Evening 1500'
Sunday Night 500'
Monday Morning 1500'
Monday Afternoon 3000'
Stevens Pass Elevation
Saturday Evening 4500'
Saturday Night 4500'
Sunday Morning 4000'
Sunday Afternoon 3500'
Sunday Evening 1500'
Sunday Night 500'
Monday Morning 1500'
Monday Afternoon 3000'
Snoqualmie Pass Elevation
Saturday Evening 5000'
Saturday Night 4500'
Sunday Morning 4500'
Sunday Afternoon 4000'
Sunday Evening 1500'
Sunday Night 500'
Monday Morning 1500'
Monday Afternoon 3000'
East North Elevation
Saturday Evening 5000'
Saturday Night 4000'
Sunday Morning 4500'
Sunday Afternoon 4000'
Sunday Evening 1500'
Sunday Night 500'
Monday Morning 1500'
Monday Afternoon 3500'
East Central Elevation
Saturday Evening 6000'
Saturday Night 5000'
Sunday Morning 5500'
Sunday Afternoon 4500'
Sunday Evening 1500'
Sunday Night 500'
Monday Morning 1500'
Monday Afternoon 3500'
East South Elevation
Saturday Evening 7000'
Saturday Night 6000'
Sunday Morning 5500'
Sunday Afternoon 5000'
Sunday Evening 1500'
Sunday Night 500'
Monday Morning 1500'
Monday Afternoon 3500'
Mt. Hood Elevation
Saturday Evening 9000'
Saturday Night 8000'
Sunday Morning 6500'
Sunday Afternoon 5500'
Sunday Evening 1500'
Sunday Night 500'
Monday Morning 1500'
Monday Afternoon 4000'

Issued: 2:32 PM PDT Saturday, March 27, 2021

5000' Temperatures (°F)

Saturday Night Sunday
Max / Min Max / Min
Olympics 35 / 30 30 / 20
West North 32 / 30 29 / 21
West Central 34 / 30 30 / 22
West South 37 / 32 34 / 23
Stevens Pass 36 / 30 33 / 24
Snoqualmie Pass 35 / 30 34 / 23
East North 37 / 31 32 / 23
East Central 38 / 31 33 / 23
East South 42 / 31 35 / 27
Mt. Hood 44 / 35 40 / 30
Olympics 5000' Temperature Forecast
(Max / Min)
Saturday Night 35 / 30
Sunday 30 / 20
West North 5000' Temperature Forecast
(Max / Min)
Saturday Night 32 / 30
Sunday 29 / 21
West Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 34 / 30
Sunday 30 / 22
West South 5000' Temperature Forecast
(Max / Min)
Saturday Night 37 / 32
Sunday 34 / 23
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 36 / 30
Sunday 33 / 24
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 35 / 30
Sunday 34 / 23
East North 5000' Temperature Forecast
(Max / Min)
Saturday Night 37 / 31
Sunday 32 / 23
East Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 38 / 31
Sunday 33 / 23
East South 5000' Temperature Forecast
(Max / Min)
Saturday Night 42 / 31
Sunday 35 / 27
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Saturday Night 44 / 35
Sunday 40 / 30

Issued: 2:32 PM PDT Saturday, March 27, 2021

Ridgeline Winds (mph)

Saturday Evening Saturday Night Sunday Morning Sunday Afternoon
Olympics WSW 10-20 SW 15-25 SW 20-30 WSW 30-40
West North WSW 10-20 SSW 20-30 SSW 25-35 SSW 35-50
West Central WSW 10-20 SW 15-25 SSW 30-40 SW 40-55
West South W 15-25 WSW 20-30 SSW 30-40 SW 40-55
Stevens Pass W 10-20 W 15-25 WSW 20-30 WSW 35-50
Snoqualmie Pass W 15-25 W 20-30 WSW 25-35 WSW 40-55
East North W 20-30 W 25-35 SW 30-40 WSW 35-50
East Central W 15-25 W 25-35 WSW 30-40 WSW 40-55
East South W 10-20 W 20-30 WSW 25-35 WSW 40-55
Mt. Hood W 10-20 W 25-35 WSW 30-40 WSW 45-65
Olympics Ridgeline Winds (mph)
Saturday Evening WSW 10-20
Saturday Night SW 15-25
Sunday Morning SW 20-30
Sunday Afternoon WSW 30-40
West North Ridgeline Winds (mph)
Saturday Evening WSW 10-20
Saturday Night SSW 20-30
Sunday Morning SSW 25-35
Sunday Afternoon SSW 35-50
West Central Ridgeline Winds (mph)
Saturday Evening WSW 10-20
Saturday Night SW 15-25
Sunday Morning SSW 30-40
Sunday Afternoon SW 40-55
West South Ridgeline Winds (mph)
Saturday Evening W 15-25
Saturday Night WSW 20-30
Sunday Morning SSW 30-40
Sunday Afternoon SW 40-55
Stevens Pass Ridgeline Winds (mph)
Saturday Evening W 10-20
Saturday Night W 15-25
Sunday Morning WSW 20-30
Sunday Afternoon WSW 35-50
Snoqualmie Pass Ridgeline Winds (mph)
Saturday Evening W 15-25
Saturday Night W 20-30
Sunday Morning WSW 25-35
Sunday Afternoon WSW 40-55
East North Ridgeline Winds (mph)
Saturday Evening W 20-30
Saturday Night W 25-35
Sunday Morning SW 30-40
Sunday Afternoon WSW 35-50
East Central Ridgeline Winds (mph)
Saturday Evening W 15-25
Saturday Night W 25-35
Sunday Morning WSW 30-40
Sunday Afternoon WSW 40-55
East South Ridgeline Winds (mph)
Saturday Evening W 10-20
Saturday Night W 20-30
Sunday Morning WSW 25-35
Sunday Afternoon WSW 40-55
Mt. Hood Ridgeline Winds (mph)
Saturday Evening W 10-20
Saturday Night W 25-35
Sunday Morning WSW 30-40
Sunday Afternoon WSW 45-65

Issued: 2:32 PM PDT Saturday, March 27, 2021

Extended Weather Synopsis

An upper ridge will build offshore on Tuesday as drier and warmer conditions take hold. Dry and increasingly warm weather should continue into Wednesday as the ridge axis shifts closer to the PNW.  Freezing levels may reach 10,000 down at Mt Hood by Wednesday. 

Extended Snow Level (ft)

Monday Night Tuesday Tuesday Night Wednesday
West North 1500' 3500' 4000' 7000'
Snoqualmie Pass 1500' 3500' 4500' 8500'
Mt. Hood 1500' 4500' 6500' 10000'
West North Elevation
Monday Night 1500'
Tuesday 3500'
Tuesday Night 4000'
Wednesday 7000'
Snoqualmie Pass Elevation
Monday Night 1500'
Tuesday 3500'
Tuesday Night 4500'
Wednesday 8500'
Mt. Hood Elevation
Monday Night 1500'
Tuesday 4500'
Tuesday Night 6500'
Wednesday 10000'

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

Previous forecast from Mar 27, 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’.