Issued: 2:08 PM PST Sunday, January 15, 2023
by Robert Hahn

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

Weather Synopsis

A closed surface low moved onshore over western Washington Sunday afternoon with bands of precipitation and cooling temperatures aloft with an associated trough. Cooler air at upper levels has created instability because temperatures below 4000 ft have been slower to cool. The most intense rain and snow is in close proximity to and south of the low where a shift to SW flow is spreading moderate rain and snow into the southern Cascades.  This moderate precipitation shifts northward Sunday night as snow levels drop to just above 3000 ft. Steady precipitation quickly tapers to decreasing rain and snow showers focused near and west of the Cascade Crest on Monday with snow levels around 3000 ft for most areas. Mt. Baker, Paradise, and Mt. St Helens should pick up 8-12" of snow through Monday while most other areas can expect 1-4" accumulations above the rain-snow line. Very light W flow aloft translates to light ridgeline winds on Monday. Expect increasing sun breaks for the east slopes of the Cascades south of I-90 and Mt. Hood as the day progresses.

Moisture lingers with a continuing chance of light showers Monday night with weak W flow. A split jetstream keeps the more active weather south of us in California.

A "dirty ridge" on Wednesday will bring a chance of very light precipitation for the west slopes of the Cascades with a warm front moving into the nearshore waters.

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
Sunday Night Light rain and snow.
Monday Decreasing light rain and snow showers.
Sunday Night Increasing moderate to heavy rain and snow.
Monday Decreasing moderate rain and snow becoming light by the afternoon.
Sunday Night Increasing moderate rain and snow.
Monday Decreasing light rain and snow showers.
Sunday Night Decreasing light rain and snow (moderate to heavy at Paradise and Mt. St Helens).
Monday Decreasing light rain and snow showers.
Sunday Night Light rain and snow. Light ridgeline and E wind at the Pass.
Monday Light rain and snow showers. Light ridgeline and W wind at the Pass.
Sunday Night Light rain and snow. Light ridgeline and E becoming variable wind at the Pass.
Monday Light rain and snow showers. Light ridgeline and W wind at the Pass.
Sunday Night Light rain and snow.
Monday Decreasing light rain and snow showers.
Sunday Night Light rain and snow.
Monday Very light rain and snow showers.
Sunday Night Decreasing light rain and snow.
Monday Partly cloudy.
Sunday Night Decreasing light rain and snow.
Monday Very light rain and snow showers with increasing chances for sun breaks.

Issued: 2:08 PM PST Sunday, January 15, 2023

Precipitation (in)

Sunday Night Monday Monday Night Tuesday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge LT 0.25 LT 0.25 LT 0.10 0
Mt Baker Ski Area 1.00 0.50 LT 0.10 LT 0.10
Mt. Loop - Barlow Pass 0.50 LT 0.25 LT 0.10 LT 0.10
Stevens Pass LT 0.25 LT 0.10 LT 0.10 LT 0.10
Snoqualmie Pass 0.25 LT 0.10 LT 0.10 LT 0.10
Crystal Mt 0.25 - 0.50 LT 0.10 0 LT 0.10
Paradise 0.75 LT 0.25 LT 0.10 LT 0.25
White Pass 0.25 LT 0.10 0 LT 0.10
Washington Pass LT 0.25 LT 0.10 0 0
Mission Ridge LT 0.10 0 0 0
Salmon la Sac - Gallagher Head 0.25 LT 0.10 0 0
Tieton River - Darland Mt. LT 0.10 0 0 0
Mt Hood Meadows LT 0.25 LT 0.10 LT 0.10 LT 0.10
Timberline LT 0.25 LT 0.10 LT 0.10 LT 0.10
Hurricane Ridge Precipitation (in)
Sunday Night LT 0.25
Monday LT 0.25
Monday Night LT 0.10
Tuesday 0
Mt Baker Ski Area Precipitation (in)
Sunday Night 1.00
Monday 0.50
Monday Night LT 0.10
Tuesday LT 0.10
Mt. Loop - Barlow Pass Precipitation (in)
Sunday Night 0.50
Monday LT 0.25
Monday Night LT 0.10
Tuesday LT 0.10
Stevens Pass Precipitation (in)
Sunday Night LT 0.25
Monday LT 0.10
Monday Night LT 0.10
Tuesday LT 0.10
Snoqualmie Pass Precipitation (in)
Sunday Night 0.25
Monday LT 0.10
Monday Night LT 0.10
Tuesday LT 0.10
Crystal Mt Precipitation (in)
Sunday Night 0.25 - 0.50
Monday LT 0.10
Monday Night 0
Tuesday LT 0.10
Paradise Precipitation (in)
Sunday Night 0.75
Monday LT 0.25
Monday Night LT 0.10
Tuesday LT 0.25
White Pass Precipitation (in)
Sunday Night 0.25
Monday LT 0.10
Monday Night 0
Tuesday LT 0.10
Washington Pass Precipitation (in)
Sunday Night LT 0.25
Monday LT 0.10
Monday Night 0
Tuesday 0
Mission Ridge Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday 0
Salmon la Sac - Gallagher Head Precipitation (in)
Sunday Night 0.25
Monday LT 0.10
Monday Night 0
Tuesday 0
Tieton River - Darland Mt. Precipitation (in)
Sunday Night LT 0.10
Monday 0
Monday Night 0
Tuesday 0
Mt Hood Meadows Precipitation (in)
Sunday Night LT 0.25
Monday LT 0.10
Monday Night LT 0.10
Tuesday LT 0.10
Timberline Precipitation (in)
Sunday Night LT 0.25
Monday LT 0.10
Monday Night LT 0.10
Tuesday LT 0.10

Issued: 2:08 PM PST Sunday, January 15, 2023

Snow Level (ft)

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

Issued: 2:08 PM PST Sunday, January 15, 2023

5000' Temperatures (°F)

Sunday Night Monday
Max / Min Max / Min
Olympics 28 / 26 28 / 26
West North 28 / 27 27 / 25
West Central 27 / 26 26 / 25
West South 28 / 25 27 / 25
Stevens Pass 27 / 26 29 / 24
Snoqualmie Pass 27 / 26 27 / 24
East North 27 / 24 29 / 25
East Central 27 / 24 29 / 24
East South 28 / 24 28 / 23
Mt. Hood 27 / 24 28 / 23
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday Night 28 / 26
Monday 28 / 26
West North 5000' Temperature Forecast
(Max / Min)
Sunday Night 28 / 27
Monday 27 / 25
West Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 26
Monday 26 / 25
West South 5000' Temperature Forecast
(Max / Min)
Sunday Night 28 / 25
Monday 27 / 25
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 26
Monday 29 / 24
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 26
Monday 27 / 24
East North 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 24
Monday 29 / 25
East Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 24
Monday 29 / 24
East South 5000' Temperature Forecast
(Max / Min)
Sunday Night 28 / 24
Monday 28 / 23
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 24
Monday 28 / 23

Issued: 2:08 PM PST Sunday, January 15, 2023

Ridgeline Winds (mph)

Sunday Evening Sunday Night Monday Morning Monday Afternoon
Olympics SSW 5-15 SSW 15-25 SSW 10-20 SSW 5-15
West North SSE 10-20 S 15-25 S 15-25 S 10-20
West Central SSE 10-20 SSW 15-25 SSW 10-20 SW 5-15
West South SW 15-25 SW 5-15 SW 0-10 SW 0-10
Stevens Pass SSE 5-15 SW 5-15 SW 0-10 W 0-10
Snoqualmie Pass SE 5-15 SW 10-20 SW 0-10 W 0-10
East North SE 10-20 SSW 5-15 SW 5-15 WSW 5-15
East Central SSW 10-20 WSW 15-25 WSW 5-15 W 0-10
East South WSW 15-25 WSW 10-20 W 5-15 W 0-10
Mt. Hood WSW 20-30 WSW 15-25 WSW 5-15 WSW 0-10
Olympics Ridgeline Winds (mph)
Sunday Evening SSW 5-15
Sunday Night SSW 15-25
Monday Morning SSW 10-20
Monday Afternoon SSW 5-15
West North Ridgeline Winds (mph)
Sunday Evening SSE 10-20
Sunday Night S 15-25
Monday Morning S 15-25
Monday Afternoon S 10-20
West Central Ridgeline Winds (mph)
Sunday Evening SSE 10-20
Sunday Night SSW 15-25
Monday Morning SSW 10-20
Monday Afternoon SW 5-15
West South Ridgeline Winds (mph)
Sunday Evening SW 15-25
Sunday Night SW 5-15
Monday Morning SW 0-10
Monday Afternoon SW 0-10
Stevens Pass Ridgeline Winds (mph)
Sunday Evening SSE 5-15
Sunday Night SW 5-15
Monday Morning SW 0-10
Monday Afternoon W 0-10
Snoqualmie Pass Ridgeline Winds (mph)
Sunday Evening SE 5-15
Sunday Night SW 10-20
Monday Morning SW 0-10
Monday Afternoon W 0-10
East North Ridgeline Winds (mph)
Sunday Evening SE 10-20
Sunday Night SSW 5-15
Monday Morning SW 5-15
Monday Afternoon WSW 5-15
East Central Ridgeline Winds (mph)
Sunday Evening SSW 10-20
Sunday Night WSW 15-25
Monday Morning WSW 5-15
Monday Afternoon W 0-10
East South Ridgeline Winds (mph)
Sunday Evening WSW 15-25
Sunday Night WSW 10-20
Monday Morning W 5-15
Monday Afternoon W 0-10
Mt. Hood Ridgeline Winds (mph)
Sunday Evening WSW 20-30
Sunday Night WSW 15-25
Monday Morning WSW 5-15
Monday Afternoon WSW 0-10

Issued: 2:08 PM PST Sunday, January 15, 2023

Extended Weather Synopsis

A warm front arrives Tuesday night with a trailing cold front Wednesday morning. This one should be cold enough for snow, but recent model simulations have shown a tendency for the system's energy to split southward into California. Currently, we're expecting 4-6" snowfall amounts for the west slopes of the Cascades with 2000-3000 ft snow levels with very light post-frontal showers lingering through Thursday.

Extended Snow Level (ft)

Tuesday Night* Wednesday * Wednesday Night Thursday
West North 2000' 2500' 2000' 2500'
Snoqualmie Pass 2500' 2500' 2000' 2500'
Mt. Hood 2500' 3000' 2000' 2500'
West North Elevation
Tuesday Night* 2000'
Wednesday * 2500'
Wednesday Night 2000'
Thursday 2500'
Snoqualmie Pass Elevation
Tuesday Night* 2500'
Wednesday * 2500'
Wednesday Night 2000'
Thursday 2500'
Mt. Hood Elevation
Tuesday Night* 2500'
Wednesday * 3000'
Wednesday Night 2000'
Thursday 2500'

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

Previous forecast from Jan 15, 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’.