Issued: 2:06 PM PST Monday, February 15, 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 low-pressure center is into NW Washington State. A cold front ahead is attempting to move through the Cascades but continues to be blocked by cold, dense air streaming through the passes and mountain gaps on easterly flow. Milder air has been spilling over the top of the cold air pool which can be discerned by the inversions present at the Alpental weather stations. The front continues to bring heavy snowfall Monday afternoon. The heavy snowfall should continue as the cold front winds the battle of the air masses and moves to the east of the Cascades Monday night, switching low-level winds westerly and bumping temperatures up to near 30F at Snoqualmie Pass. Expect increasing westerly ridgeline winds along the east slopes of the Cascades behind the front with strong winds developing at Mt. Hood.

A switch to WNW flow behind the front will bring heavy snowfall above 1500-2500 ft with the heaviest precipitation in convergence bands forming late Monday night and Tuesday. Snow should gradually decrease and become increasingly showery Tuesday night, then very light on Wednesday as a ridge begins building offshore. Wednesday should be colder with low snow levels in all areas.

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 Decreasing light rain and snow.
Tuesday Periods of light rain and snow.
Monday Night Periods of light snow.
Tuesday Periods of light to occasionally moderate snow.
Monday Night Light to moderate snow.
Tuesday Light to moderate snow.
Monday Night Moderate to heavy rain and snow.
Tuesday Light to moderate snow, heaviest at Paradise.
Monday Night Moderate snow. Convergence banding possible after midnight. Light E winds shifting W at the Pass during the evening hours.
Tuesday Moderate snow. Convergence at times. Light W winds at the Pass.
Monday Night Moderate to heavy snow. Convergence banding possible after midnight. Light to moderate E shifting W winds at the Pass.
Tuesday Moderate snow. Convergence at times. Light E winds shifting W at the Pass during the evening hours.
Monday Night Light snow at times.
Tuesday Light snow at times.
Monday Night Light to moderate snow.
Tuesday Periods of light snow mainly in convergence spillover.
Monday Night Moderate rain and snow.
Tuesday Light rain and snow.
Monday Night Heavy rain and snow. Strong ridgeline winds.
Tuesday Moderate to heavy snow. Moderate to strong ridgeline winds.

Issued: 2:06 PM PST Monday, February 15, 2021

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 0.25 LT 0.10 0 0
Mt Baker Ski Area LT 0.10 0.25 LT 0.25 LT 0.10
Mt. Loop - Barlow Pass 0.25 0.25 0.25 - 0.50 LT 0.10
Stevens Pass 0.25 - 0.50 0.25 - 0.50 0.25 - 0.50 LT 0.10
Snoqualmie Pass 0.75 0.50 0.50 LT 0.10
Crystal Mt 0.50 - 0.75 0.25 LT 0.25 LT 0.10
Paradise 0.75 -1.00 0.50 - 0.75 LT 0.25 LT 0.10
White Pass 0.75 0.25 LT 0.25 LT 0.10
Washington Pass LT 0.25 LT 0.10 LT 0.10 LT 0.10
Mission Ridge LT 0.10 LT 0.10 0 0
Salmon la Sac - Gallagher Head 0.25 - 0.50 LT 0.25 LT 0.25 LT 0.10
Tieton River - Darland Mt. 0.50 LT 0.25 LT 0.10 0
Mt Hood Meadows 1.00 0.50 - 0.75 0.25 - 0.50 LT 0.10
Timberline 1.00 - 1.50 0.75 0.25 - 0.50 LT 0.25
Hurricane Ridge Precipitation (in)
Monday Night 0.25
Tuesday LT 0.10
Tuesday Night 0
Wednesday 0
Mt Baker Ski Area Precipitation (in)
Monday Night LT 0.10
Tuesday 0.25
Tuesday Night LT 0.25
Wednesday LT 0.10
Mt. Loop - Barlow Pass Precipitation (in)
Monday Night 0.25
Tuesday 0.25
Tuesday Night 0.25 - 0.50
Wednesday LT 0.10
Stevens Pass Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.25 - 0.50
Tuesday Night 0.25 - 0.50
Wednesday LT 0.10
Snoqualmie Pass Precipitation (in)
Monday Night 0.75
Tuesday 0.50
Tuesday Night 0.50
Wednesday LT 0.10
Crystal Mt Precipitation (in)
Monday Night 0.50 - 0.75
Tuesday 0.25
Tuesday Night LT 0.25
Wednesday LT 0.10
Paradise Precipitation (in)
Monday Night 0.75 -1.00
Tuesday 0.50 - 0.75
Tuesday Night LT 0.25
Wednesday LT 0.10
White Pass Precipitation (in)
Monday Night 0.75
Tuesday 0.25
Tuesday Night LT 0.25
Wednesday LT 0.10
Washington Pass Precipitation (in)
Monday Night LT 0.25
Tuesday LT 0.10
Tuesday Night LT 0.10
Wednesday LT 0.10
Mission Ridge Precipitation (in)
Monday Night LT 0.10
Tuesday LT 0.10
Tuesday Night 0
Wednesday 0
Salmon la Sac - Gallagher Head Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday LT 0.25
Tuesday Night LT 0.25
Wednesday LT 0.10
Tieton River - Darland Mt. Precipitation (in)
Monday Night 0.50
Tuesday LT 0.25
Tuesday Night LT 0.10
Wednesday 0
Mt Hood Meadows Precipitation (in)
Monday Night 1.00
Tuesday 0.50 - 0.75
Tuesday Night 0.25 - 0.50
Wednesday LT 0.10
Timberline Precipitation (in)
Monday Night 1.00 - 1.50
Tuesday 0.75
Tuesday Night 0.25 - 0.50
Wednesday LT 0.25

Issued: 2:06 PM PST Monday, February 15, 2021

Snow Level (ft)

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

Issued: 2:06 PM PST Monday, February 15, 2021

5000' Temperatures (°F)

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

Issued: 2:06 PM PST Monday, February 15, 2021

Ridgeline Winds (mph)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon
Olympics WNW 5-15 WNW 10-20 WNW 10-20 WNW 10-20
West North WNW 0-10 W 5-15 W 10-20 W 20-30
West Central W 10-20 WNW 10-20 WNW 10-20 WNW 20-30
West South WNW 10-20 WNW 10-20 WNW 15-25 WNW 20-30
Stevens Pass WNW 10-20 WNW 10-20 W 10-20 WNW 15-25
Snoqualmie Pass WNW 15-25 WNW 15-25 WNW 15-25 WNW 25-35
East North WNW 5-15 WNW 10-20 W 10-20 W 20-30
East Central WNW 15-25 WNW 20-30 WNW 20-30 WNW 25-35
East South W 15-25 WNW 20-30 WNW 15-25 WNW 15-25
Mt. Hood W 30-40 W 25-35 W 25-35 W 20-30
Olympics Ridgeline Winds (mph)
Monday Evening WNW 5-15
Monday Night WNW 10-20
Tuesday Morning WNW 10-20
Tuesday Afternoon WNW 10-20
West North Ridgeline Winds (mph)
Monday Evening WNW 0-10
Monday Night W 5-15
Tuesday Morning W 10-20
Tuesday Afternoon W 20-30
West Central Ridgeline Winds (mph)
Monday Evening W 10-20
Monday Night WNW 10-20
Tuesday Morning WNW 10-20
Tuesday Afternoon WNW 20-30
West South Ridgeline Winds (mph)
Monday Evening WNW 10-20
Monday Night WNW 10-20
Tuesday Morning WNW 15-25
Tuesday Afternoon WNW 20-30
Stevens Pass Ridgeline Winds (mph)
Monday Evening WNW 10-20
Monday Night WNW 10-20
Tuesday Morning W 10-20
Tuesday Afternoon WNW 15-25
Snoqualmie Pass Ridgeline Winds (mph)
Monday Evening WNW 15-25
Monday Night WNW 15-25
Tuesday Morning WNW 15-25
Tuesday Afternoon WNW 25-35
East North Ridgeline Winds (mph)
Monday Evening WNW 5-15
Monday Night WNW 10-20
Tuesday Morning W 10-20
Tuesday Afternoon W 20-30
East Central Ridgeline Winds (mph)
Monday Evening WNW 15-25
Monday Night WNW 20-30
Tuesday Morning WNW 20-30
Tuesday Afternoon WNW 25-35
East South Ridgeline Winds (mph)
Monday Evening W 15-25
Monday Night WNW 20-30
Tuesday Morning WNW 15-25
Tuesday Afternoon WNW 15-25
Mt. Hood Ridgeline Winds (mph)
Monday Evening W 30-40
Monday Night W 25-35
Tuesday Morning W 25-35
Tuesday Afternoon W 20-30

Issued: 2:06 PM PST Monday, February 15, 2021

Extended Weather Synopsis

A short-lived ridge moves over the region Wednesday night. Expect increasing clouds ahead of the next frontal system arriving Thursday. Mountain snow should increase throughout the day on Thursday with SW flow focusing moderate precipitation on the southern parts of the forecast area. Snow should. Expect heavy post-frontal snowfall across the west slopes of the Cascades and Passes Thursday night as flow turns westerly.  Snowfall should still be moderate to heavy and gradually decreasing as temperatures cool on Friday.

Extended Snow Level (ft)

Wednesday Night* Thursday * Thursday Night* Friday
West North 1500' 1500' 2000' 1500'
Snoqualmie Pass 1500' 1500' 1500' 2000'
Mt. Hood 2500' 2500' 3500' 3000'
West North Elevation
Wednesday Night* 1500'
Thursday * 1500'
Thursday Night* 2000'
Friday 1500'
Snoqualmie Pass Elevation
Wednesday Night* 1500'
Thursday * 1500'
Thursday Night* 1500'
Friday 2000'
Mt. Hood Elevation
Wednesday Night* 2500'
Thursday * 2500'
Thursday Night* 3500'
Friday 3000'

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

Previous forecast from Feb 15, 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’.