Issued: 2:40 PM PDT Thursday, March 21, 2024
by Robert Hahn

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

Weather Synopsis

A weak ridge of high pressure strengthens through Friday morning. A deeper low spinning off the Oregon coast ejects weak disturbances northward into the region as the low center drifts northeastward. The interplay between these two weather features brings a mix of sun, clouds, and light bands of showery precipitation. The timing of these bands and the associated cloud cover will be difficult to predict precisely. At this time, it appears that the first band moves north from a weak circulation center just off the Washington Coast on Thursday afternoon. This feature spreads up to 0.1" of water equivalent into the Washington Cascades Thursday night, with higher amounts possible for the southern Olympics. Snow levels fluctuate around 5000 ft. The weak precipitation band likely dissipates near the Canadian border Friday morning, giving areas further south some fair weather with filtered sunshine, high cloud cover and freezing levels peaking around 6500-7500 ft.

The more substantial frontal rain band pushes the region from south to N as the broad closed low approaches Friday afternoon. Rain and higher elevation snow levels start around 5500-6000 ft, but drop to around 4000 ft where they remain fairly steady on Saturday. Light to moderate rain and snow focus peak in the southern Cascades Friday evening, the central Cascades overnight, and the northern Cascades throughout the day on Saturday. Easterly low-level flow and SSE upper-level winds will favor the E slopes of the Cascades, so expect fairly comparable precipitation amounts on both sides of the Cascades. Most areas can expect 0.5-1.5" of snow water equivalent by the end of the day Saturday, translating to 6-18" of snow above the shifting rain-snow line.

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
Thursday Night Cloudy with increasing chances of light rain or snow showers.
Friday Mostly cloudy in the morning with a chance of rain or snow showers; becoming cloudy with light rain and snow showers increasing.
Thursday Night Partly cloudy in the evening, then cloudy with a chance of light rain and snow showers after midnight.
Friday Cloudy with a few light rain and snow.
Thursday Night Mostly cloudy with light rain and snow showers at times.
Friday Cloudy with a few light rain and snow showers at times.
Thursday Night Mostly cloudy with light rain and snow showers at times.
Friday Partly cloudy in the morning, then cloudy with increasing light rain and snow.
Thursday Night Mostly cloudy with light rain and snow showers at times. Light ridgeline and light W wind at the Pass shifts E in the early morning hours.
Friday Mostly cloudy with increasing chances of light rain and snow showers. Increasing light ridgeline and light E wind at the Pass.
Thursday Night Mostly cloudy with light rain and snow showers at times. Light ridgeline and light W wind at the Pass shifts E in the early morning hours.
Friday Mostly cloudy with increasing chances of light rain and snow showers. Increasing light to moderate ridgeline and light to occasionally moderate E wind at the Pass.
Thursday Night Partly cloudy with clouds increasing in the early morning hours.
Friday Mostly cloudy with a slight chance of light rain or snow showers in the afternoon.
Thursday Night Partly cloudy, with clouds increasing in the early morning hours.
Friday Mostly cloudy with increasing clouds and light rain or snow showers developing in the afternoon.
Thursday Night Partly cloudy with a chance of sprinkles or flurries near the Cascade Crest.
Friday Mostly cloudy with increasing clouds and light rain or snow showers developing in the afternoon.
Thursday Night High overcast. Mild.
Friday A high overcast to start the day, then light rain and snow showers develop around the mid-day hours. Moderate ridgeline winds.

Issued: 2:40 PM PDT Thursday, March 21, 2024

Precipitation (in)

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

Issued: 2:40 PM PDT Thursday, March 21, 2024

Snow Level (ft)

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

Issued: 2:40 PM PDT Thursday, March 21, 2024

5000' Temperatures (°F)

Thursday Night Friday
Max / Min Max / Min
Olympics 35 / 32 40 / 33
West North 33 / 31 42 / 31
West Central 34 / 31 40 / 33
West South 35 / 34 39 / 32
Stevens Pass 35 / 32 39 / 33
Snoqualmie Pass 34 / 33 38 / 33
East North 35 / 29 38 / 29
East Central 35 / 33 38 / 33
East South 35 / 33 38 / 31
Mt. Hood 38 / 34 41 / 37
Olympics 5000' Temperature Forecast
(Max / Min)
Thursday Night 35 / 32
Friday 40 / 33
West North 5000' Temperature Forecast
(Max / Min)
Thursday Night 33 / 31
Friday 42 / 31
West Central 5000' Temperature Forecast
(Max / Min)
Thursday Night 34 / 31
Friday 40 / 33
West South 5000' Temperature Forecast
(Max / Min)
Thursday Night 35 / 34
Friday 39 / 32
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Thursday Night 35 / 32
Friday 39 / 33
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Thursday Night 34 / 33
Friday 38 / 33
East North 5000' Temperature Forecast
(Max / Min)
Thursday Night 35 / 29
Friday 38 / 29
East Central 5000' Temperature Forecast
(Max / Min)
Thursday Night 35 / 33
Friday 38 / 33
East South 5000' Temperature Forecast
(Max / Min)
Thursday Night 35 / 33
Friday 38 / 31
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Thursday Night 38 / 34
Friday 41 / 37

Issued: 2:40 PM PDT Thursday, March 21, 2024

Ridgeline Winds (mph)

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

Issued: 2:40 PM PDT Thursday, March 21, 2024

Extended Weather Synopsis

The upper low morphs into a broad trough Saturday night as the surface feature shifts across the Cascades. Flow shifts NNWerly through Sunday with light rain and snow showers continuing for the central Washington Cascades south to Mt Hood. Snow levels drop to around 3000 ft by Sunday. Temperatures remain cool Sunday night with clearing skies as a subtle shortwave ridge moves over the region. A shortwave trough arrives with scattered showers and 3000-3500 ft snow levels on Monday.

Extended Snow Level (ft)

Saturday Night Sunday Sunday Night Monday
West North 3500' 4000' 4000' 3000'
Snoqualmie Pass 3500' 3000' 3000' 3000'
Mt. Hood 4000' 3500' 3500' 3500'
West North Elevation
Saturday Night 3500'
Sunday 4000'
Sunday Night 4000'
Monday 3000'
Snoqualmie Pass Elevation
Saturday Night 3500'
Sunday 3000'
Sunday Night 3000'
Monday 3000'
Mt. Hood Elevation
Saturday Night 4000'
Sunday 3500'
Sunday Night 3500'
Monday 3500'

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

Previous forecast from Mar 21, 2024

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’.