A fast-moving low pressure system walloped the area today with heavy snowfall with snow levels near sea level, and strong winds in many areas. We are well on our way to storm totals between 12-30 inches. As of 2 pm, the back edge of the heavier snowfall associated with the cold front is dropping from NW to SE and moving into the central/south Washington Cascades and down to Mt. Hood.
As the front drops further south this evening, expect rapid cooling to erase any relative warming trend that occurred today. Strong west winds will continue south of Hwy 2 through this evening. Post-frontal showers in westerly flow will add another few inches along the west slopes of the Cascades and Passes overnight. A weak convergence zone is likely to form this afternoon and last through the early morning hours between Stevens and Snoqualmie Pass. Mt. Hood will continue to see heavy snowfall rates of several inches an hour last through early tonight. Also for Mt Hood, West winds will be extreme, even for a place that's no stranger to wind.
The winter solstice will greet us with what will likely be the coldest day of the year. High pressure will build offshore, leading to a general drying trend. While many areas will see mid-day/afternoon sun on Wednesday to help feign warmth, morning low clouds are likely to stick around for Stevens/Snoqualmie Passes and along east slopes of the Cascades. Weak easterly flow may even squeeze out a few flurries in these locations.
Very strong offshore flow will develop Wednesday night and Thursday, driving the coldest regional air across the Cascade crest. Expect strong and gusty East winds in the Passes, leading to a dangerously cold wind chill. The next frontal system will approach on Thursday. Clouds will increase Wednesday night with light snow developing either Thursday or Thursday night.
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
Tuesday
Night
Mostly cloudy with isolated light snow showers
Wednesday
Partly sunny. Very cold.
Tuesday
Night
Mostly cloudy with isolated light snow showers
Wednesday
Partly to mostly cloudy in the morning with a chance of snow showers, partly sunny in the afternoon. Very cold.
Tuesday
Night
Light snow showers in the evening, becoming scattered after midnight.
Wednesday
Mostly cloudy in the morning with scattered snow showers, partly sunny in the afternoon with increasing high clouds. Very cold.
Tuesday
Night
Light to occasionally moderate snow showers in the evening, becoming scattered after midnight. Strong ridgeline winds decreasing after midnight.
Wednesday
Mostly cloudy in the morning, partly sunny in the afternoon with increasing high clouds. Very cold.
Tuesday
Night
Light snow showers in the evening, becoming scattered after midnight. Moderate ridgeline and Pass level west winds decreasing after midnight.
Wednesday
Cloudy with a chance of flurries. Light east wind increasing at Pass level in the afternoon.
Tuesday
Night
Light to occasionally moderate snow showers in the evening, becoming scattered after midnight. Moderate to strong ridgeline and Pass level west winds decreasing after midnight.
Wednesday
Cloudy with a chance of flurries. Light east wind increasing at Pass level in the afternoon.
Tuesday
Night
Mostly cloudy with isolated snow showers.
Wednesday
Partly cloudy in the morning, partly sunny in the afternoon. Very cold.
Tuesday
Night
Light snow showers in the evening, becoming scattered after midnight. Strong ridgeline winds decreasing late.
Wednesday
Mostly cloudy with low clouds and a chance of flurries. More sun higher terrain. Very cold.
Tuesday
Night
Light snow showers in the evening, becoming scattered after midnight. Strong ridgeline winds decreasing late.
Wednesday
Mostly cloudy with low clouds and a chance of flurries. More sun higher terrain. Very cold.
Tuesday
Night
Moderate to occasionally heavy snow becoming light to moderate snow showers after midnight. Strong winds, extreme in the alpine.
Wednesday
Mostly cloudy with scattered snow showers in the morning, then partly sunny. Strong ridgeline winds decreasing in the afternoon.
Issued: 2:00 PM PST Tuesday, December 20, 2022
Precipitation (in)
Tuesday Night
Wednesday
Wednesday Night
Thursday
4 pm - 4 am
4 am - 4 pm
4 pm - 4 am
4 am - 4 pm
Hurricane Ridge
LT 0.10
0
0
LT 0.10
Mt Baker Ski Area
LT 0.25
0
0
LT 0.10
Mt. Loop - Barlow Pass
LT 0.25
0
0
LT 0.10
Stevens Pass
LT 0.25
0
0
LT 0.10
Snoqualmie Pass
0.25
0
0
LT 0.10
Crystal Mt
LT 0.25
0
0
LT 0.10
Paradise
0.25
0
0
0.25
White Pass
0.25
0
0
LT 0.10
Washington Pass
LT 0.10
0
0
LT 0.10
Mission Ridge
LT 0.10
0
0
LT 0.10
Salmon la Sac - Gallagher Head
LT 0.25
0
0
LT 0.10
Tieton River - Darland Mt.
LT 0.25
0
0
LT 0.10
Mt Hood Meadows
0.75
0
0
LT 0.25
Timberline
0.75 -1.00
0
0
LT 0.25
Hurricane Ridge
Precipitation (in)
Tuesday Night
LT 0.10
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Mt Baker Ski Area
Precipitation (in)
Tuesday Night
LT 0.25
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Mt. Loop - Barlow Pass
Precipitation (in)
Tuesday Night
LT 0.25
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Stevens Pass
Precipitation (in)
Tuesday Night
LT 0.25
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Snoqualmie Pass
Precipitation (in)
Tuesday Night
0.25
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Crystal Mt
Precipitation (in)
Tuesday Night
LT 0.25
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Paradise
Precipitation (in)
Tuesday Night
0.25
Wednesday
0
Wednesday Night
0
Thursday
0.25
White Pass
Precipitation (in)
Tuesday Night
0.25
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Washington Pass
Precipitation (in)
Tuesday Night
LT 0.10
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Mission Ridge
Precipitation (in)
Tuesday Night
LT 0.10
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Salmon la Sac - Gallagher Head
Precipitation (in)
Tuesday Night
LT 0.25
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Tieton River - Darland Mt.
Precipitation (in)
Tuesday Night
LT 0.25
Wednesday
0
Wednesday Night
0
Thursday
LT 0.10
Mt Hood Meadows
Precipitation (in)
Tuesday Night
0.75
Wednesday
0
Wednesday Night
0
Thursday
LT 0.25
Timberline
Precipitation (in)
Tuesday Night
0.75 -1.00
Wednesday
0
Wednesday Night
0
Thursday
LT 0.25
Issued: 2:00 PM PST Tuesday, December 20, 2022
Snow Level (ft)
Tuesday
Evening
Tuesday
Night
Wednesday
Morning
Wednesday
Afternoon*
Wednesday
Evening*
Wednesday
Night*
Thursday
Morning*
Thursday
Afternoon*
Olympics
0
0
0
0
0
0
0
500'
West North
0
0
0
0
0
0
0
0
West Central
0
0
0
0
0
0
0
0
West South
1000'
0
0
0
0
0
0
0
Stevens Pass
0
0
0
0
0
0
0
0
Snoqualmie Pass
0
0
0
0
0
0
0
0
East North
0
0
0
0
0
0
0
0
East Central
0
0
0
0
0
0
0
0
East South
1500'
0
0
0
0
0
0
0
Mt. Hood
4500'
1500'
0
0
0
0
0
0
Olympics
Elevation
Tuesday
Evening
0'
Tuesday
Night
0'
Wednesday
Morning
0'
Wednesday
Afternoon*
0'
Wednesday
Evening*
0'
Wednesday
Night*
0'
Thursday
Morning*
0'
Thursday
Afternoon*
500'
West North
Elevation
Tuesday
Evening
0'
Tuesday
Night
0'
Wednesday
Morning
0'
Wednesday
Afternoon*
0'
Wednesday
Evening*
0'
Wednesday
Night*
0'
Thursday
Morning*
0'
Thursday
Afternoon*
0'
West Central
Elevation
Tuesday
Evening
0'
Tuesday
Night
0'
Wednesday
Morning
0'
Wednesday
Afternoon*
0'
Wednesday
Evening*
0'
Wednesday
Night*
0'
Thursday
Morning*
0'
Thursday
Afternoon*
0'
West South
Elevation
Tuesday
Evening
1000'
Tuesday
Night
0'
Wednesday
Morning
0'
Wednesday
Afternoon*
0'
Wednesday
Evening*
0'
Wednesday
Night*
0'
Thursday
Morning*
0'
Thursday
Afternoon*
0'
Stevens Pass
Elevation
Tuesday
Evening
0'
Tuesday
Night
0'
Wednesday
Morning
0'
Wednesday
Afternoon*
0'
Wednesday
Evening*
0'
Wednesday
Night*
0'
Thursday
Morning*
0'
Thursday
Afternoon*
0'
Snoqualmie Pass
Elevation
Tuesday
Evening
0'
Tuesday
Night
0'
Wednesday
Morning
0'
Wednesday
Afternoon*
0'
Wednesday
Evening*
0'
Wednesday
Night*
0'
Thursday
Morning*
0'
Thursday
Afternoon*
0'
East North
Elevation
Tuesday
Evening
0'
Tuesday
Night
0'
Wednesday
Morning
0'
Wednesday
Afternoon*
0'
Wednesday
Evening*
0'
Wednesday
Night*
0'
Thursday
Morning*
0'
Thursday
Afternoon*
0'
East Central
Elevation
Tuesday
Evening
0'
Tuesday
Night
0'
Wednesday
Morning
0'
Wednesday
Afternoon*
0'
Wednesday
Evening*
0'
Wednesday
Night*
0'
Thursday
Morning*
0'
Thursday
Afternoon*
0'
East South
Elevation
Tuesday
Evening
1500'
Tuesday
Night
0'
Wednesday
Morning
0'
Wednesday
Afternoon*
0'
Wednesday
Evening*
0'
Wednesday
Night*
0'
Thursday
Morning*
0'
Thursday
Afternoon*
0'
Mt. Hood
Elevation
Tuesday
Evening
4500'
Tuesday
Night
1500'
Wednesday
Morning
0'
Wednesday
Afternoon*
0'
Wednesday
Evening*
0'
Wednesday
Night*
0'
Thursday
Morning*
0'
Thursday
Afternoon*
0'
Issued: 2:00 PM PST Tuesday, December 20, 2022
5000' Temperatures (°F)
Tuesday
Night
Wednesday
Max / Min
Max / Min
Olympics
16 / 11
15 / 10
West North
15 / 9
10 / 2
West Central
16 / 10
12 / 5
West South
23 / 13
14 / 7
Stevens Pass
18 / 13
13 / 6
Snoqualmie Pass
19 / 14
13 / 7
East North
9 / -1
5 / -5
East Central
13 / 3
7 / -2
East South
23 / 10
10 / 0
Mt. Hood
32 / 19
22 / 15
Olympics
5000' Temperature Forecast (Max / Min)
Tuesday
Night
16 / 11
Wednesday
15 / 10
West North
5000' Temperature Forecast (Max / Min)
Tuesday
Night
15 / 9
Wednesday
10 / 2
West Central
5000' Temperature Forecast (Max / Min)
Tuesday
Night
16 / 10
Wednesday
12 / 5
West South
5000' Temperature Forecast (Max / Min)
Tuesday
Night
23 / 13
Wednesday
14 / 7
Stevens Pass
5000' Temperature Forecast (Max / Min)
Tuesday
Night
18 / 13
Wednesday
13 / 6
Snoqualmie Pass
5000' Temperature Forecast (Max / Min)
Tuesday
Night
19 / 14
Wednesday
13 / 7
East North
5000' Temperature Forecast (Max / Min)
Tuesday
Night
9 / -1
Wednesday
5 / -5
East Central
5000' Temperature Forecast (Max / Min)
Tuesday
Night
13 / 3
Wednesday
7 / -2
East South
5000' Temperature Forecast (Max / Min)
Tuesday
Night
23 / 10
Wednesday
10 / 0
Mt. Hood
5000' Temperature Forecast (Max / Min)
Tuesday
Night
32 / 19
Wednesday
22 / 15
Issued: 2:00 PM PST Tuesday, December 20, 2022
Ridgeline Winds (mph)
Tuesday
Evening
Tuesday
Night
Wednesday
Morning
Wednesday
Afternoon
Olympics
WSW 10-20
W 5-15
WNW 0-10
NW 0-10
West North
WSW 5-15
WSW 0-10
VAR 0-10
ENE 0-10
West Central
W 10-20
W 5-15
W 0-10
VAR 0-10
West South
W 20-30
W 15-25
WNW 5-15
NW 0-10
Stevens Pass
W 15-25
W 5-15
WNW 5-15
ESE 0-10
Snoqualmie Pass
WSW 20-30
W 15-25
WNW 5-15
ESE 5-15
East North
W 10-20
W 10-20
NW 5-15
VAR 0-10
East Central
W 25-35
WNW 15-25
WNW 10-20
ESE 0-10
East South
W 25-35
WNW 15-25
NW 5-15
VAR 0-10
Mt. Hood
W 40-55
W 40-55
WNW 25-35
W 15-25
Olympics
Ridgeline Winds (mph)
Tuesday
Evening
WSW
10-20
Tuesday
Night
W
5-15
Wednesday
Morning
WNW
0-10
Wednesday
Afternoon
NW
0-10
West North
Ridgeline Winds (mph)
Tuesday
Evening
WSW
5-15
Tuesday
Night
WSW
0-10
Wednesday
Morning
VAR
0-10
Wednesday
Afternoon
ENE
0-10
West Central
Ridgeline Winds (mph)
Tuesday
Evening
W
10-20
Tuesday
Night
W
5-15
Wednesday
Morning
W
0-10
Wednesday
Afternoon
VAR
0-10
West South
Ridgeline Winds (mph)
Tuesday
Evening
W
20-30
Tuesday
Night
W
15-25
Wednesday
Morning
WNW
5-15
Wednesday
Afternoon
NW
0-10
Stevens Pass
Ridgeline Winds (mph)
Tuesday
Evening
W
15-25
Tuesday
Night
W
5-15
Wednesday
Morning
WNW
5-15
Wednesday
Afternoon
ESE
0-10
Snoqualmie Pass
Ridgeline Winds (mph)
Tuesday
Evening
WSW
20-30
Tuesday
Night
W
15-25
Wednesday
Morning
WNW
5-15
Wednesday
Afternoon
ESE
5-15
East North
Ridgeline Winds (mph)
Tuesday
Evening
W
10-20
Tuesday
Night
W
10-20
Wednesday
Morning
NW
5-15
Wednesday
Afternoon
VAR
0-10
East Central
Ridgeline Winds (mph)
Tuesday
Evening
W
25-35
Tuesday
Night
WNW
15-25
Wednesday
Morning
WNW
10-20
Wednesday
Afternoon
ESE
0-10
East South
Ridgeline Winds (mph)
Tuesday
Evening
W
25-35
Tuesday
Night
WNW
15-25
Wednesday
Morning
NW
5-15
Wednesday
Afternoon
VAR
0-10
Mt. Hood
Ridgeline Winds (mph)
Tuesday
Evening
W
40-55
Tuesday
Night
W
40-55
Wednesday
Morning
WNW
25-35
Wednesday
Afternoon
W
15-25
Issued: 2:00 PM PST Tuesday, December 20, 2022
Extended Weather Synopsis
We'll see another N-S frontal system arrive on Friday. Each consecutive system will take a bite out of the very cold air mass over the region with a gradual warming trend over several days. By Saturday, an even stronger frontal system (potential atmospheric river) will arrive with even warmer temperatures that pushes milder across the Cascades and into eastern Washington/Oregon. This will be a messy transition, with periods of heavy snow, freezing rain, and eventually rain in some areas. Many details are up in the air, but there's high confidence we are beginning to pivot from a cold and snowy pattern to a milder and wetter pattern in the extended.
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).