Issued: 2:11 PM PST Monday, March 8, 2021
by Robert Hahn

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

Weather Synopsis

A vertically stacked low continues to drift slowly southward well off the Washington coastline. Multiple disturbances will eject northward into our region during the early part of the week.

The first disturbance lifts northward along the Oregon coastline on Monday afternoon, spreading increasing light snow showers into Mt. Hood and southern Washington Cascades. Precipitation should increase and extend northward into the Olympics and Mt. Rainier areas during the evening hours before largely fizzling out overnight. Monday night should be cool, but not as cold as Sunday night with clouds limiting radiational cooling.

Another weak shortwave will move northward across the region during the day Tuesday with snow levels around 3000 ft. This feature should distribute light snow showers more evenly across the Casades with a dusting to 2" expected throughout the region.

Tuesday night the next wave shouldn't make it as far north, so expect a chance of snow showers for Mt. Hood and the southern Washington Cascades. As the upper low exits and the atmosphere remains weakly unstable, a shortwave moving into our region from British Colombia may touch off light snow showers Wednesday afternoon.

Light E winds through the mountain gaps will continue through Tuesday night and then switch westerly as the offshore low moves sufficiently far to our south.

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
Monday Night Very light snow showers in the northern Olympics with slightly more substantial snow showers in the southern and eastern Olympics.
Tuesday Mostly cloudy with light snow showers increasing in the afternoon.
Monday Night Mostly cloudy with a very slight chance of light snow showers by morning.
Tuesday Mostly cloudy with a chance of light snow showers.
Monday Night Mostly cloudy.
Tuesday Mostly cloudy with chances of light snow showers increasing in the afternoon.
Monday Night Mostly cloudy with a chance of light snow showers.
Tuesday Light snow showers.
Monday Night Mostly cloudy. Light E winds at the Pass.
Tuesday Mostly cloudy in the morning with light snow showers in the afternoon. Light E winds at the Pass.
Monday Night Mostly with a slight chance of light snow showers in the early morning hours. Light E winds at the Pass.
Tuesday Mostly cloudy in the morning with light snow showers in the afternoon. Light E winds at the Pass.
Monday Night Mostly cloudy.
Tuesday Mostly cloudy in the morning with light snow showers in the afternoon.
Monday Night Mostly with a slight chance of light snow showers in the early morning hours.
Tuesday Mostly cloudy in the morning with light snow showers in the afternoon.
Monday Night Mostly cloudy with light snow showers.
Tuesday Light snow showers at times.
Monday Night Light to moderate snow showers.
Tuesday Light snow showers.

Precipitation (in)

Monday Night Tuesday Tuesday Night Wednesday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge LT 0.10 LT 0.25 0 LT 0.10
Mt Baker Ski Area 0 LT 0.10 0 LT 0.10
Mt. Loop - Barlow Pass 0 LT 0.10 0 LT 0.10
Stevens Pass 0 LT 0.10 0 LT 0.10
Snoqualmie Pass 0 LT 0.10 0 LT 0.10
Crystal Mt LT 0.10 LT 0.10 LT 0.10 LT 0.10
Paradise LT 0.10 LT 0.10 LT 0.10 LT 0.10
White Pass LT 0.10 0 LT 0.10 LT 0.10
Washington Pass 0 LT 0.10 LT 0.10 LT 0.10
Mission Ridge 0 LT 0.10 LT 0.10 LT 0.10
Salmon la Sac - Gallagher Head 0 LT 0.10 LT 0.10 LT 0.10
Tieton River - Darland Mt. LT 0.10 LT 0.10 LT 0.10 LT 0.10
Mt Hood Meadows 0.25 LT 0.25 LT 0.25 LT 0.10
Timberline 0.25 LT 0.25 LT 0.25 LT 0.10
Hurricane Ridge Precipitation (in)
Monday Night LT 0.10
Tuesday LT 0.25
Tuesday Night 0
Wednesday LT 0.10
Mt Baker Ski Area Precipitation (in)
Monday Night 0
Tuesday LT 0.10
Tuesday Night 0
Wednesday LT 0.10
Mt. Loop - Barlow Pass Precipitation (in)
Monday Night 0
Tuesday LT 0.10
Tuesday Night 0
Wednesday LT 0.10
Stevens Pass Precipitation (in)
Monday Night 0
Tuesday LT 0.10
Tuesday Night 0
Wednesday LT 0.10
Snoqualmie Pass Precipitation (in)
Monday Night 0
Tuesday LT 0.10
Tuesday Night 0
Wednesday LT 0.10
Crystal Mt Precipitation (in)
Monday Night LT 0.10
Tuesday LT 0.10
Tuesday Night LT 0.10
Wednesday LT 0.10
Paradise Precipitation (in)
Monday Night LT 0.10
Tuesday LT 0.10
Tuesday Night LT 0.10
Wednesday LT 0.10
White Pass Precipitation (in)
Monday Night LT 0.10
Tuesday 0
Tuesday Night LT 0.10
Wednesday LT 0.10
Washington Pass Precipitation (in)
Monday Night 0
Tuesday LT 0.10
Tuesday Night LT 0.10
Wednesday LT 0.10
Mission Ridge Precipitation (in)
Monday Night 0
Tuesday LT 0.10
Tuesday Night LT 0.10
Wednesday LT 0.10
Salmon la Sac - Gallagher Head Precipitation (in)
Monday Night 0
Tuesday LT 0.10
Tuesday Night LT 0.10
Wednesday LT 0.10
Tieton River - Darland Mt. Precipitation (in)
Monday Night LT 0.10
Tuesday LT 0.10
Tuesday Night LT 0.10
Wednesday LT 0.10
Mt Hood Meadows Precipitation (in)
Monday Night 0.25
Tuesday LT 0.25
Tuesday Night LT 0.25
Wednesday LT 0.10
Timberline Precipitation (in)
Monday Night 0.25
Tuesday LT 0.25
Tuesday Night LT 0.25
Wednesday LT 0.10

Snow Level (ft)

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

5000' Temperatures (°F)

Monday Night Tuesday
Max / Min Max / Min
Olympics 28 / 20 26 / 19
West North 30 / 19 27 / 18
West Central 27 / 18 28 / 17
West South 28 / 19 29 / 19
Stevens Pass 27 / 18 30 / 17
Snoqualmie Pass 26 / 17 28 / 15
East North 26 / 18 29 / 17
East Central 26 / 18 29 / 17
East South 26 / 17 30 / 16
Mt. Hood 25 / 20 31 / 22
Olympics 5000' Temperature Forecast
(Max / Min)
Monday Night 28 / 20
Tuesday 26 / 19
West North 5000' Temperature Forecast
(Max / Min)
Monday Night 30 / 19
Tuesday 27 / 18
West Central 5000' Temperature Forecast
(Max / Min)
Monday Night 27 / 18
Tuesday 28 / 17
West South 5000' Temperature Forecast
(Max / Min)
Monday Night 28 / 19
Tuesday 29 / 19
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 27 / 18
Tuesday 30 / 17
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 26 / 17
Tuesday 28 / 15
East North 5000' Temperature Forecast
(Max / Min)
Monday Night 26 / 18
Tuesday 29 / 17
East Central 5000' Temperature Forecast
(Max / Min)
Monday Night 26 / 18
Tuesday 29 / 17
East South 5000' Temperature Forecast
(Max / Min)
Monday Night 26 / 17
Tuesday 30 / 16
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday Night 25 / 20
Tuesday 31 / 22

Ridgeline Winds (mph)

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

Extended Weather Synopsis

A shortwave trough extending SW from British Columbia should keep very light snow shower activity alive Wednesday evening. Showers should end and skies clear overnight as flow turns northerly and a ridge of high pressure moves into the region through Friday. Plan for mild afternoons and cool mornings with shallow inversions. Winds will be very light throughout the time period.

Extended Snow Level (ft)

Wednesday Night Thursday Thursday Night Friday
West North 2000' 3000' 2500' 3500'
Snoqualmie Pass 2000' 3500' 3000' 4000'
Mt. Hood 3000' 3500' 3000' 4500'
West North Elevation
Wednesday Night 2000'
Thursday 3000'
Thursday Night 2500'
Friday 3500'
Snoqualmie Pass Elevation
Wednesday Night 2000'
Thursday 3500'
Thursday Night 3000'
Friday 4000'
Mt. Hood Elevation
Wednesday Night 3000'
Thursday 3500'
Thursday Night 3000'
Friday 4500'

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

Previous forecast from Mar 8, 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’.