Issued: 2:43 PM PDT Friday, April 23, 2021
by Robert Hahn

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

Weather Synopsis

A broad trough gradually approaches the PNW coastline Friday night through Saturday night, bringing a return to cooler, wetter, and more winter-like conditions across the region. A front appears just off the coast on the radar as of Friday afternoon. This band of light rain/snow should lift NE across the region, racing the Olympics and Cascades primarily after midnight Friday night with snow levels initially above 4500 ft. Additional bands of moisture should follow as temperatures cool during the early morning hours on Saturday with snow levels lowering to 3000-4500 ft by Saturday. Precipitation becomes somewhat more continuous but remains banded on Saturday and Saturday night. Warming afternoon temperatures will limit snow accumulations below around 4000 ft.

Colder air aloft moves in with the arrival of the broad upper trough on Sunday. Expect a mix of sun and more convective rain and snow showers. There's a slight chance of an isolated thunderstorm, primarily for the southern Washington Cascades and Mt. Hood areas. Temperatures remain cool, but the thermometer may spike during longer periods of sunshine.

SW winds peak late Saturday, before decreasing and shifting primarily westerly on Sunday.

Expect storm totals of 4-8” above the snow line for the Olympics and west Slopes of the Cascades with 1-3” further east.

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
Friday Night Cloudy with increasing chances of light rain or snow, mainly after midnight.
Saturday Light rain and snow.
Friday Night Cloudy with increasing chances of light rain or snow, mainly after midnight.
Saturday Light rain and snow.
Friday Night Cloudy with increasing chances of light rain or snow, mainly after midnight.
Saturday Light rain and snow.
Friday Night Cloudy with increasing chances of light rain or snow, mainly after midnight.
Saturday Light to occasionally moderate rain and snow.
Friday Night Cloudy with increasing chances of light rain or snow, mainly after midnight.
Saturday Light rain and snow.
Friday Night Cloudy with increasing chances of light rain or snow, mainly after midnight.
Saturday Light rain and snow.
Friday Night Mostly cloudy with increasing chances of light rain or snow, mainly after midnight.
Saturday Increasing periods of light rain and snow.
Friday Night Mostly cloudy with increasing chances of light rain or snow, mainly after midnight.
Saturday Periods of light rain and snow.
Friday Night Cloudy with a chance of light rain or snow.
Saturday Cloudy with light rain or snow at times.
Friday Night Cloudy with increasing chances of light rain or snow, mainly after midnight.
Saturday Light to occasionally moderate rain and snow.

Precipitation (in)

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

Snow Level (ft)

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

5000' Temperatures (°F)

Friday Night Saturday
Max / Min Max / Min
Olympics 35 / 29 34 / 29
West North 36 / 30 33 / 29
West Central 36 / 30 32 / 29
West South 38 / 31 35 / 30
Stevens Pass 38 / 31 35 / 31
Snoqualmie Pass 37 / 31 33 / 30
East North 39 / 31 36 / 30
East Central 39 / 31 36 / 30
East South 41 / 31 36 / 30
Mt. Hood 42 / 31 36 / 30
Olympics 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 35 / 29
Saturday 5am - 5pm 34 / 29
West North 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 36 / 30
Saturday 5am - 5pm 33 / 29
West Central 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 36 / 30
Saturday 5am - 5pm 32 / 29
West South 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 38 / 31
Saturday 5am - 5pm 35 / 30
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 38 / 31
Saturday 5am - 5pm 35 / 31
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 37 / 31
Saturday 5am - 5pm 33 / 30
East North 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 39 / 31
Saturday 5am - 5pm 36 / 30
East Central 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 39 / 31
Saturday 5am - 5pm 36 / 30
East South 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 41 / 31
Saturday 5am - 5pm 36 / 30
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Friday 5pm - 5am 42 / 31
Saturday 5am - 5pm 36 / 30

Ridgeline Winds (mph)

Friday Evening Friday Night Saturday Morning Saturday Afternoon
Olympics S 0-10 SW 5-15 SW 5-15 SW 0-10
West North SSW 5-15 S 5-15 S 0-10 SSW 5-15
West Central WSW 5-15 WSW 5-15 SW 5-15 WSW 10-20
West South WSW 5-15 WSW 5-15 SW 5-15 SW 5-15
Stevens Pass W 5-15 W 5-15 W 5-15 W 5-15
Snoqualmie Pass WNW 5-15 WNW 5-15 W 5-15 WNW 10-20
East North WSW 5-15 WSW 0-10 W 5-15 W 5-15
East Central WSW 5-15 W 10-20 W 10-20 W 10-20
East South W 5-15 W 10-20 W 5-15 WSW 10-20
Mt. Hood SW 15-25 WSW 15-25 SW 5-15 WSW 0-10
Olympics Ridgeline Winds (mph)
Friday Evening S 0-10
Friday Night SW 5-15
Saturday Morning SW 5-15
Saturday Afternoon SW 0-10
West North Ridgeline Winds (mph)
Friday Evening SSW 5-15
Friday Night S 5-15
Saturday Morning S 0-10
Saturday Afternoon SSW 5-15
West Central Ridgeline Winds (mph)
Friday Evening WSW 5-15
Friday Night WSW 5-15
Saturday Morning SW 5-15
Saturday Afternoon WSW 10-20
West South Ridgeline Winds (mph)
Friday Evening WSW 5-15
Friday Night WSW 5-15
Saturday Morning SW 5-15
Saturday Afternoon SW 5-15
Stevens Pass Ridgeline Winds (mph)
Friday Evening W 5-15
Friday Night W 5-15
Saturday Morning W 5-15
Saturday Afternoon W 5-15
Snoqualmie Pass Ridgeline Winds (mph)
Friday Evening WNW 5-15
Friday Night WNW 5-15
Saturday Morning W 5-15
Saturday Afternoon WNW 10-20
East North Ridgeline Winds (mph)
Friday Evening WSW 5-15
Friday Night WSW 0-10
Saturday Morning W 5-15
Saturday Afternoon W 5-15
East Central Ridgeline Winds (mph)
Friday Evening WSW 5-15
Friday Night W 10-20
Saturday Morning W 10-20
Saturday Afternoon W 10-20
East South Ridgeline Winds (mph)
Friday Evening W 5-15
Friday Night W 10-20
Saturday Morning W 5-15
Saturday Afternoon WSW 10-20
Mt. Hood Ridgeline Winds (mph)
Friday Evening SW 15-25
Friday Night WSW 15-25
Saturday Morning SW 5-15
Saturday Afternoon WSW 0-10

Extended Weather Synopsis

Rain and snow shower activity tapers Sunday night. A wave on the backside of the trough may increase westerly flow and bring slightly increasing rain and snow shower activity on Monday. Monday night appears mostly dry. Models diverge regarding the potential for more significant precipitation to arrive over a weak "dirty" ridge on Tuesday, but at this time it appears more likely that Tuesday will be mostly dry. Temperatures should remain near or slightly below seasonal norms.

Extended Snow Level (ft)

Sunday Night Monday Monday Night Tuesday
West North 3500' 3500' 4500' 4000'
Snoqualmie Pass 4000' 3500' 4500' 4000'
Mt. Hood 4500' 4000' 5000' 5500'
West North Elevation
Sunday Night 3500'
Monday 3500'
Monday Night 4500'
Tuesday 4000'
Snoqualmie Pass Elevation
Sunday Night 4000'
Monday 3500'
Monday Night 4500'
Tuesday 4000'
Mt. Hood Elevation
Sunday Night 4500'
Monday 4000'
Monday Night 5000'
Tuesday 5500'

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

Previous forecast from Apr 22, 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’.

Updated Mountain Weather Zone Name Changes – December 2020