A strong frontal system that ended a 48-hour atmospheric river event has pushed well to our east. The lingering showers in decreasing westerly flow should taper off over the central Washington Cascades on Wednesday evening. This leaves the region under partly clearing skies with cool temperatures. A ridge begins to build over the region, bringing milder temperatures to southern parts of the forecast region. This warming will accelerate Thursday as the ridge continues to amplify with the ridge axis over the region. A cold pool east of the Cascades below 4500 ft combined with E moderate E flow through the passes should keep the passes mostly cool on Thursday. Temperatures may rise just above freezing Thursday afternoon at locations such as Snoqualmie Pass. Meanwhile, freezing levels should be 10,500-12,000 ft in locations such as the Olympics and Mt. Hood.
A frontal system offshore will send most of its energy into British Columbia. Our region gets the weak tail end of the system late Thursday night as the ridge of high pressure slides eastward. The frontal passage should occur early Friday morning with light rain and snow from midnight Thursday night until post-frontal shower activity tapers off Friday afternoon. Snow levels should be in the 3500-8000 ft range with some lower snow levels east of the Cascade Crest and to the north, while milder air will be harder to displace further 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
Wednesday
Night
Partly to mostly clear in the evening, then becoming mostly cloudy.
Thursday
Mostly cloudy early with increasing sunshine throughout the day.
Wednesday
Night
Partly cloudy with increasing high clouds towards morning.
Thursday
Partly cloudy early with increasing clearing throughout the day.
Wednesday
Night
Snow showers lingering into the evening hours. Then, partly cloudy with increasing high clouds towards morning.
Thursday
Partly cloudy early with increasing clearing throughout the day.
Wednesday
Night
Mostly clear in the evening, then increasing high clouds after midnight.
Thursday
Partly cloudy early with increasing clearing throughout the day.
Wednesday
Night
Snow showers lingering into the evening hours. Then becoming partly to mostly cloudy. Light W wind shifting E in the late evening at pass level.
Thursday
Partly cloudy early with increasing clearing throughout the day. Light to moderate E wind at pass level.
Wednesday
Night
Snow showers lingering into the evening hours. Then becoming partly to mostly cloudy. Light W wind shifting E in the late evening and increasing into the moderate range by morning at pass level.
Thursday
Partly cloudy early with increasing clearing throughout the day. Moderate E wind at pass level.
Wednesday
Night
Mostly clear to partly cloudy skies.
Thursday
Mostly clear.
Wednesday
Night
Partly cloudy with a chance of light snow showers in the evening.
Thursday
Partly cloudy early with increasing clearing throughout the day.
Wednesday
Night
Mostly clear early then becoming mostly cloudy.
Thursday
Partly cloudy early with increasing clearing throughout the day.
Wednesday
Night
Mostly clear in the early evening then increasing high clouds.
Thursday
Partly cloudy early with increasing clearing throughout the day.
Issued: 2:09 PM PST Wednesday, January 13, 2021
Precipitation (in)
Wednesday Night
Thursday
Thursday Night
Friday
4 pm - 4 am
4 am - 4 pm
4 pm - 4 am
4 am - 4 pm
Hurricane Ridge
0
0
LT 0.10
0
Mt Baker Ski Area
0
0
0.25
LT 0.10
Mt. Loop - Barlow Pass
LT 0.10
0
LT 0.25
LT 0.25
Stevens Pass
LT 0.10
0
LT 0.10
LT 0.25
Snoqualmie Pass
LT 0.10
0
LT 0.10
LT 0.25
Crystal Mt
0
0
LT 0.10
LT 0.10
Paradise
0
0
LT 0.25
LT 0.25
White Pass
0
0
LT 0.10
LT 0.10
Washington Pass
0
0
LT 0.10
LT 0.10
Mission Ridge
0
0
0
0
Salmon la Sac - Gallagher Head
LT 0.10
0
LT 0.10
LT 0.10
Tieton River - Darland Mt.
0
0
0
LT 0.10
Mt Hood Meadows
0
0
0
LT 0.25
Timberline
0
0
0
LT 0.25
Hurricane Ridge
Precipitation (in)
Wednesday Night
0
Thursday
0
Thursday Night
LT 0.10
Friday
0
Mt Baker Ski Area
Precipitation (in)
Wednesday Night
0
Thursday
0
Thursday Night
0.25
Friday
LT 0.10
Mt. Loop - Barlow Pass
Precipitation (in)
Wednesday Night
LT 0.10
Thursday
0
Thursday Night
LT 0.25
Friday
LT 0.25
Stevens Pass
Precipitation (in)
Wednesday Night
LT 0.10
Thursday
0
Thursday Night
LT 0.10
Friday
LT 0.25
Snoqualmie Pass
Precipitation (in)
Wednesday Night
LT 0.10
Thursday
0
Thursday Night
LT 0.10
Friday
LT 0.25
Crystal Mt
Precipitation (in)
Wednesday Night
0
Thursday
0
Thursday Night
LT 0.10
Friday
LT 0.10
Paradise
Precipitation (in)
Wednesday Night
0
Thursday
0
Thursday Night
LT 0.25
Friday
LT 0.25
White Pass
Precipitation (in)
Wednesday Night
0
Thursday
0
Thursday Night
LT 0.10
Friday
LT 0.10
Washington Pass
Precipitation (in)
Wednesday Night
0
Thursday
0
Thursday Night
LT 0.10
Friday
LT 0.10
Mission Ridge
Precipitation (in)
Wednesday Night
0
Thursday
0
Thursday Night
0
Friday
0
Salmon la Sac - Gallagher Head
Precipitation (in)
Wednesday Night
LT 0.10
Thursday
0
Thursday Night
LT 0.10
Friday
LT 0.10
Tieton River - Darland Mt.
Precipitation (in)
Wednesday Night
0
Thursday
0
Thursday Night
0
Friday
LT 0.10
Mt Hood Meadows
Precipitation (in)
Wednesday Night
0
Thursday
0
Thursday Night
0
Friday
LT 0.25
Timberline
Precipitation (in)
Wednesday Night
0
Thursday
0
Thursday Night
0
Friday
LT 0.25
Issued: 2:09 PM PST Wednesday, January 13, 2021
Snow Level (ft)
Wednesday
Evening
Wednesday
Night*
Thursday
Morning*
Thursday
Afternoon*
Thursday
Evening*
Thursday
Night*
Friday
Morning
Friday
Afternoon
Olympics
2500'
3500'
5500'
10500'
8500'
7500'
5000'
5000'
West North
1500'
2000'
2500'
6500'
7000'
6500'
5000'
4500'
West Central
2000'
2000'
3500'
7000'
7000'
6500'
5500'
5000'
West South
2000'
2500'
5000'
10500'
8000'
7000'
6500'
6000'
Stevens Pass
2000'
2000'
3000'
4000'
4500'
5000'
4500'
5000'
Snoqualmie Pass
2000'
2500'
3500'
8000'
6500'
5500'
5500'
5500'
East North
1500'
1500'
2000'
3500'
3500'
3500'
4000'
5000'
East Central
2000'
2000'
3500'
4000'
5500'
5500'
4500'
5500'
East South
2500'
3000'
4500'
7000'
7000'
7000'
7000'
6500'
Mt. Hood
3500'
5000'
8500'
12000'
10000'
9500'
8000'
7500'
Olympics
Elevation
Wednesday
Evening
2500'
Wednesday
Night*
3500'
Thursday
Morning*
5500'
Thursday
Afternoon*
10500'
Thursday
Evening*
8500'
Thursday
Night*
7500'
Friday
Morning
5000'
Friday
Afternoon
5000'
West North
Elevation
Wednesday
Evening
1500'
Wednesday
Night*
2000'
Thursday
Morning*
2500'
Thursday
Afternoon*
6500'
Thursday
Evening*
7000'
Thursday
Night*
6500'
Friday
Morning
5000'
Friday
Afternoon
4500'
West Central
Elevation
Wednesday
Evening
2000'
Wednesday
Night*
2000'
Thursday
Morning*
3500'
Thursday
Afternoon*
7000'
Thursday
Evening*
7000'
Thursday
Night*
6500'
Friday
Morning
5500'
Friday
Afternoon
5000'
West South
Elevation
Wednesday
Evening
2000'
Wednesday
Night*
2500'
Thursday
Morning*
5000'
Thursday
Afternoon*
10500'
Thursday
Evening*
8000'
Thursday
Night*
7000'
Friday
Morning
6500'
Friday
Afternoon
6000'
Stevens Pass
Elevation
Wednesday
Evening
2000'
Wednesday
Night*
2000'
Thursday
Morning*
3000'
Thursday
Afternoon*
4000'
Thursday
Evening*
4500'
Thursday
Night*
5000'
Friday
Morning
4500'
Friday
Afternoon
5000'
Snoqualmie Pass
Elevation
Wednesday
Evening
2000'
Wednesday
Night*
2500'
Thursday
Morning*
3500'
Thursday
Afternoon*
8000'
Thursday
Evening*
6500'
Thursday
Night*
5500'
Friday
Morning
5500'
Friday
Afternoon
5500'
East North
Elevation
Wednesday
Evening
1500'
Wednesday
Night*
1500'
Thursday
Morning*
2000'
Thursday
Afternoon*
3500'
Thursday
Evening*
3500'
Thursday
Night*
3500'
Friday
Morning
4000'
Friday
Afternoon
5000'
East Central
Elevation
Wednesday
Evening
2000'
Wednesday
Night*
2000'
Thursday
Morning*
3500'
Thursday
Afternoon*
4000'
Thursday
Evening*
5500'
Thursday
Night*
5500'
Friday
Morning
4500'
Friday
Afternoon
5500'
East South
Elevation
Wednesday
Evening
2500'
Wednesday
Night*
3000'
Thursday
Morning*
4500'
Thursday
Afternoon*
7000'
Thursday
Evening*
7000'
Thursday
Night*
7000'
Friday
Morning
7000'
Friday
Afternoon
6500'
Mt. Hood
Elevation
Wednesday
Evening
3500'
Wednesday
Night*
5000'
Thursday
Morning*
8500'
Thursday
Afternoon*
12000'
Thursday
Evening*
10000'
Thursday
Night*
9500'
Friday
Morning
8000'
Friday
Afternoon
7500'
Issued: 2:09 PM PST Wednesday, January 13, 2021
5000' Temperatures (°F)
Wednesday
Night
Thursday
Max / Min
Max / Min
Olympics
32 / 24
41 / 32
West North
26 / 21
37 / 26
West Central
29 / 21
35 / 29
West South
31 / 24
35 / 31
Stevens Pass
29 / 22
32 / 29
Snoqualmie Pass
31 / 23
33 / 31
East North
21 / 16
24 / 18
East Central
27 / 22
30 / 27
East South
30 / 22
32 / 30
Mt. Hood
40 / 29
46 / 40
Olympics
5000' Temperature Forecast (Max / Min)
Wednesday
Night
32 / 24
Thursday
41 / 32
West North
5000' Temperature Forecast (Max / Min)
Wednesday
Night
26 / 21
Thursday
37 / 26
West Central
5000' Temperature Forecast (Max / Min)
Wednesday
Night
29 / 21
Thursday
35 / 29
West South
5000' Temperature Forecast (Max / Min)
Wednesday
Night
31 / 24
Thursday
35 / 31
Stevens Pass
5000' Temperature Forecast (Max / Min)
Wednesday
Night
29 / 22
Thursday
32 / 29
Snoqualmie Pass
5000' Temperature Forecast (Max / Min)
Wednesday
Night
31 / 23
Thursday
33 / 31
East North
5000' Temperature Forecast (Max / Min)
Wednesday
Night
21 / 16
Thursday
24 / 18
East Central
5000' Temperature Forecast (Max / Min)
Wednesday
Night
27 / 22
Thursday
30 / 27
East South
5000' Temperature Forecast (Max / Min)
Wednesday
Night
30 / 22
Thursday
32 / 30
Mt. Hood
5000' Temperature Forecast (Max / Min)
Wednesday
Night
40 / 29
Thursday
46 / 40
Issued: 2:09 PM PST Wednesday, January 13, 2021
Ridgeline Winds (mph)
Wednesday
Evening
Wednesday
Night
Thursday
Morning
Thursday
Afternoon
Olympics
VAR 0-10
S 5-15
S 10-20
S 15-25
West North
WSW 5-15
VAR 0-10
S 10-20
S 15-25
West Central
WNW 5-15
VAR 0-10
S 5-15
S 10-20
West South
W 5-15
W 5-15
SSE 5-15
S 10-20
Stevens Pass
W 5-15
VAR 0-10
ESE 10-20
ESE 10-20
Snoqualmie Pass
W 10-20
SW 0-10
ESE 10-20
ESE 10-20
East North
W 10-20
VAR 0-10
SE 5-15
SE 5-15
East Central
W 15-25
SW 0-10
SE 10-20
SE 10-20
East South
W 10-20
SSW 5-15
SE 5-15
S 5-15
Mt. Hood
WSW 5-15
S 5-15
SSW 10-20
SW 15-25
Olympics
Ridgeline Winds (mph)
Wednesday
Evening
VAR
0-10
Wednesday
Night
S
5-15
Thursday
Morning
S
10-20
Thursday
Afternoon
S
15-25
West North
Ridgeline Winds (mph)
Wednesday
Evening
WSW
5-15
Wednesday
Night
VAR
0-10
Thursday
Morning
S
10-20
Thursday
Afternoon
S
15-25
West Central
Ridgeline Winds (mph)
Wednesday
Evening
WNW
5-15
Wednesday
Night
VAR
0-10
Thursday
Morning
S
5-15
Thursday
Afternoon
S
10-20
West South
Ridgeline Winds (mph)
Wednesday
Evening
W
5-15
Wednesday
Night
W
5-15
Thursday
Morning
SSE
5-15
Thursday
Afternoon
S
10-20
Stevens Pass
Ridgeline Winds (mph)
Wednesday
Evening
W
5-15
Wednesday
Night
VAR
0-10
Thursday
Morning
ESE
10-20
Thursday
Afternoon
ESE
10-20
Snoqualmie Pass
Ridgeline Winds (mph)
Wednesday
Evening
W
10-20
Wednesday
Night
SW
0-10
Thursday
Morning
ESE
10-20
Thursday
Afternoon
ESE
10-20
East North
Ridgeline Winds (mph)
Wednesday
Evening
W
10-20
Wednesday
Night
VAR
0-10
Thursday
Morning
SE
5-15
Thursday
Afternoon
SE
5-15
East Central
Ridgeline Winds (mph)
Wednesday
Evening
W
15-25
Wednesday
Night
SW
0-10
Thursday
Morning
SE
10-20
Thursday
Afternoon
SE
10-20
East South
Ridgeline Winds (mph)
Wednesday
Evening
W
10-20
Wednesday
Night
SSW
5-15
Thursday
Morning
SE
5-15
Thursday
Afternoon
S
5-15
Mt. Hood
Ridgeline Winds (mph)
Wednesday
Evening
WSW
5-15
Wednesday
Night
S
5-15
Thursday
Morning
SSW
10-20
Thursday
Afternoon
SW
15-25
Issued: 2:09 PM PST Wednesday, January 13, 2021
Extended Weather Synopsis
Broad ridging across the western US amplifies Friday night and Saturday, centering along the west coast and bringing dry weather. Another tail end of a weakening frontal system moves through late Saturday night and Sunday morning with light rain and snow tapering to light post-frontal shower activity by Sunday afternoon.
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).