Issued: 4:45 PM PST Monday, January 2, 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

A frontal system is weakening and splitting as it runs into a strong ridge of high pressure anchored over the inland NW this afternoon. Precipitation remains offshore while high clouds stream from south to north over the area. While precipitation has remained at bay, low clouds covering the east slopes of the Cascades continue to be pulled through the major Cascade Passes and create locally breezy E-SE winds. Offshore flow and winds will weaken tonight as the front pushes into the coast.  A trailing upper level feature will swing through tomorrow morning, bringing light and scattered showers to the region. Areas that saw ridgelines winds out of the E-SE, will see the direction flop around to W.  We'll also see a slight warming trend tomorrow on both sides of the Cascades in the afternoon as the lower atmosphere becomes better mixed. 

A similar weak frontal system will arrive Tuesday night and may bring another round of light showers.  A very deep low pressure system well offshore will meander closer to our area on Wednesday.  Warm frontal moisture may reach the Mt Hood region by the afternoon along with light upslope snow on the east side of the Cascades south of L. Chelan. Offshore pressure graidents and E-SE winds will begin to increase Wednesday afternoon as well, a trend that will increase Wednesday night. 

445 PM Update: Slightly increased West North/Mt Baker area precipitation forecast for Tuesday and wind speeds for West North/Olympics late tonight and Tuesday morning. 

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 Cloudy with periods of moderate ridgeline winds. Chace of showers overnight.
Tuesday Cloudy with scattered light rain and snow showers.
Monday Night Cloudy with periods of moderate ridgeline winds.
Tuesday Cloudy with scattered light rain and snow showers. Periods of moderate wind.
Monday Night Cloudy with periods of moderate ridgeline winds.
Tuesday Cloudy with scattered light rain and snow showers. Periods of moderate ridgeline winds.
Monday Night Cloudy with periods of moderate winds.
Tuesday Cloudy with scattered light rain and snow showers.
Monday Night Cloudy. Moderate E-SE Pass level and ridgeline winds easing overnight.
Tuesday Cloudy with scattered light rain and snow showers. Light east winds at Pass level.
Monday Night Cloudy. Moderate E-SE Pass level and ridgeline winds easing overnight.
Tuesday Cloudy with scattered light rain and snow showers. Light east winds at Pass level.
Monday Night Mostly cloudy.
Tuesday Cloudy with scattered light rain and snow showers.
Monday Night Mostly with periods of moderate winds.
Tuesday Cloudy with scattered light rain and snow showers. Periods of moderate ridgeline winds.
Monday Night Mostly with periods of moderate ridgeline winds.
Tuesday Cloudy with scattered light rain and snow showers. Periods of moderate ridgeline winds.
Monday Night Cloudy with scattered light rain and snow showers.
Tuesday Cloudy with scattered light rain and snow showers. Periods of moderate ridgeline winds.

Issued: 4:45 PM PST Monday, January 2, 2023

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

Issued: 4:45 PM PST Monday, January 2, 2023

Snow Level (ft)

Monday Evening* Monday Night* Tuesday Morning* Tuesday Afternoon* Tuesday Evening* Tuesday Night* Wednesday Morning* Wednesday Afternoon*
Olympics 4500' 3500' 3500' 3500' 4500' 3000' 3000' 4500'
West North 2500' 2000' 2000' 2500' 2500' 1500' 2500' 4000'
West Central 1500' 1500' 2000' 2500' 2000' 1500' 1500' 2500'
West South 1000' 1500' 2000' 3000' 2000' 1500' 1500' 2500'
Stevens Pass 500' 500' 1500' 2500' 1000' 0 0 1000'
Snoqualmie Pass 1000' 1000' 1500' 2500' 1500' 1000' 1000' 1500'
East North 0 0 1000' 2500' 1000' 0 0 1000'
East Central 500' 0 1000' 2500' 1000' 0 0 1000'
East South 500' 500' 1000' 2500' 1500' 500' 500' 1000'
Mt. Hood 1000' 2000' 2500' 3500' 3000' 2500' 2000' 1500'
Olympics Elevation
Monday Evening* 4500'
Monday Night* 3500'
Tuesday Morning* 3500'
Tuesday Afternoon* 3500'
Tuesday Evening* 4500'
Tuesday Night* 3000'
Wednesday Morning* 3000'
Wednesday Afternoon* 4500'
West North Elevation
Monday Evening* 2500'
Monday Night* 2000'
Tuesday Morning* 2000'
Tuesday Afternoon* 2500'
Tuesday Evening* 2500'
Tuesday Night* 1500'
Wednesday Morning* 2500'
Wednesday Afternoon* 4000'
West Central Elevation
Monday Evening* 1500'
Monday Night* 1500'
Tuesday Morning* 2000'
Tuesday Afternoon* 2500'
Tuesday Evening* 2000'
Tuesday Night* 1500'
Wednesday Morning* 1500'
Wednesday Afternoon* 2500'
West South Elevation
Monday Evening* 1000'
Monday Night* 1500'
Tuesday Morning* 2000'
Tuesday Afternoon* 3000'
Tuesday Evening* 2000'
Tuesday Night* 1500'
Wednesday Morning* 1500'
Wednesday Afternoon* 2500'
Stevens Pass Elevation
Monday Evening* 500'
Monday Night* 500'
Tuesday Morning* 1500'
Tuesday Afternoon* 2500'
Tuesday Evening* 1000'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 1000'
Snoqualmie Pass Elevation
Monday Evening* 1000'
Monday Night* 1000'
Tuesday Morning* 1500'
Tuesday Afternoon* 2500'
Tuesday Evening* 1500'
Tuesday Night* 1000'
Wednesday Morning* 1000'
Wednesday Afternoon* 1500'
East North Elevation
Monday Evening* 0'
Monday Night* 0'
Tuesday Morning* 1000'
Tuesday Afternoon* 2500'
Tuesday Evening* 1000'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 1000'
East Central Elevation
Monday Evening* 500'
Monday Night* 0'
Tuesday Morning* 1000'
Tuesday Afternoon* 2500'
Tuesday Evening* 1000'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 1000'
East South Elevation
Monday Evening* 500'
Monday Night* 500'
Tuesday Morning* 1000'
Tuesday Afternoon* 2500'
Tuesday Evening* 1500'
Tuesday Night* 500'
Wednesday Morning* 500'
Wednesday Afternoon* 1000'
Mt. Hood Elevation
Monday Evening* 1000'
Monday Night* 2000'
Tuesday Morning* 2500'
Tuesday Afternoon* 3500'
Tuesday Evening* 3000'
Tuesday Night* 2500'
Wednesday Morning* 2000'
Wednesday Afternoon* 1500'

Issued: 4:45 PM PST Monday, January 2, 2023

5000' Temperatures (°F)

Monday Night Tuesday
Max / Min Max / Min
Olympics 28 / 25 27 / 23
West North 27 / 24 28 / 24
West Central 26 / 23 27 / 23
West South 25 / 22 27 / 23
Stevens Pass 24 / 19 26 / 20
Snoqualmie Pass 24 / 21 26 / 21
East North 19 / 14 23 / 17
East Central 21 / 15 25 / 20
East South 22 / 16 28 / 20
Mt. Hood 25 / 20 30 / 24
Olympics 5000' Temperature Forecast
(Max / Min)
Monday Night 28 / 25
Tuesday 27 / 23
West North 5000' Temperature Forecast
(Max / Min)
Monday Night 27 / 24
Tuesday 28 / 24
West Central 5000' Temperature Forecast
(Max / Min)
Monday Night 26 / 23
Tuesday 27 / 23
West South 5000' Temperature Forecast
(Max / Min)
Monday Night 25 / 22
Tuesday 27 / 23
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 24 / 19
Tuesday 26 / 20
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 24 / 21
Tuesday 26 / 21
East North 5000' Temperature Forecast
(Max / Min)
Monday Night 19 / 14
Tuesday 23 / 17
East Central 5000' Temperature Forecast
(Max / Min)
Monday Night 21 / 15
Tuesday 25 / 20
East South 5000' Temperature Forecast
(Max / Min)
Monday Night 22 / 16
Tuesday 28 / 20
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday Night 25 / 20
Tuesday 30 / 24

Issued: 4:45 PM PST Monday, January 2, 2023

Ridgeline Winds (mph)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon
Olympics S 15-25 SSW 20-30 S 15-25 S 5-15
West North S 10-20 S 20-30 S 15-25 S 10-20
West Central SW 5-15 SW 10-20 SW 10-20 SW 10-20
West South S 5-15 SW 10-20 SW 5-15 SW 5-15
Stevens Pass SSE 5-15 WSW 5-15 W 5-15 W 5-15
Snoqualmie Pass SE 10-20 WSW 10-20 W 10-20 W 5-15
East North S 5-15 SW 5-15 WSW 5-15 W 5-15
East Central S 10-20 W 10-20 WSW 10-20 W 5-15
East South SSW 5-15 WSW 10-20 WSW 5-15 W 5-15
Mt. Hood SW 5-15 WSW 10-20 WSW 10-20 WSW 5-15
Olympics Ridgeline Winds (mph)
Monday Evening S 15-25
Monday Night SSW 20-30
Tuesday Morning S 15-25
Tuesday Afternoon S 5-15
West North Ridgeline Winds (mph)
Monday Evening S 10-20
Monday Night S 20-30
Tuesday Morning S 15-25
Tuesday Afternoon S 10-20
West Central Ridgeline Winds (mph)
Monday Evening SW 5-15
Monday Night SW 10-20
Tuesday Morning SW 10-20
Tuesday Afternoon SW 10-20
West South Ridgeline Winds (mph)
Monday Evening S 5-15
Monday Night SW 10-20
Tuesday Morning SW 5-15
Tuesday Afternoon SW 5-15
Stevens Pass Ridgeline Winds (mph)
Monday Evening SSE 5-15
Monday Night WSW 5-15
Tuesday Morning W 5-15
Tuesday Afternoon W 5-15
Snoqualmie Pass Ridgeline Winds (mph)
Monday Evening SE 10-20
Monday Night WSW 10-20
Tuesday Morning W 10-20
Tuesday Afternoon W 5-15
East North Ridgeline Winds (mph)
Monday Evening S 5-15
Monday Night SW 5-15
Tuesday Morning WSW 5-15
Tuesday Afternoon W 5-15
East Central Ridgeline Winds (mph)
Monday Evening S 10-20
Monday Night W 10-20
Tuesday Morning WSW 10-20
Tuesday Afternoon W 5-15
East South Ridgeline Winds (mph)
Monday Evening SSW 5-15
Monday Night WSW 10-20
Tuesday Morning WSW 5-15
Tuesday Afternoon W 5-15
Mt. Hood Ridgeline Winds (mph)
Monday Evening SW 5-15
Monday Night WSW 10-20
Tuesday Morning WSW 10-20
Tuesday Afternoon WSW 5-15

Issued: 4:45 PM PST Monday, January 2, 2023

Extended Weather Synopsis

As the deep low pressure system nears the coast, we'll see light snow and E-SE winds become strong and felt over a wide area. Strong S through E winds will last through Thursday. The east slopes of the Cascades south of I-90 and the Mt Hood area may see the most snow out of this system.  A trailing occluded front will weaken into showers as it pushs through on Thursday.  From there, we'll see a series of impulses in SW flow bring light to occasionally moderate showers to our mountains. Temperatures/snow levels look like they gradually warm through the end of the week. 

Extended Snow Level (ft)

Wednesday Night* Thursday * Thursday Night* Friday *
West North 2500' 4500' 4000' 4000'
Snoqualmie Pass 1500' 2500' 3500' 5000'
Mt. Hood 1500' 3000' 4500' 5500'
West North Elevation
Wednesday Night* 2500'
Thursday * 4500'
Thursday Night* 4000'
Friday * 4000'
Snoqualmie Pass Elevation
Wednesday Night* 1500'
Thursday * 2500'
Thursday Night* 3500'
Friday * 5000'
Mt. Hood Elevation
Wednesday Night* 1500'
Thursday * 3000'
Thursday Night* 4500'
Friday * 5500'

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

Previous forecast from Jan 2, 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’.