The last weekend of the 2023/2024 avalanche forecasting season features mostly dry conditions and light winds thanks to a “split flow” pattern. The split flow results from an upper-level low dropping south off the California Coastline while a weak northern branch of the jetstream resides to our north in British Columbia. Through Sunday morning, the broad region of clouds and unsettled weather extends northward to approximately Mt Hood and at times into the southernmost Washington Cascades. A weak disturbance wrapping around the low Saturday afternoon and evening may bring some scattered showers or even a few thunderstorms to these areas.
The major story will be the warmth. Significant warming occurred during the day on Friday with 5000 ft temperatures rising into the upper 30s and 40s in most areas. Freezing levels continue to rise rapidly Friday and remain steady in the 6,500-9,500 ft range overnight. Mostly clear skies should assist overnight refreezes in open areas thanks to radiational cooling. Freezing levels rise to 8,500-10,000 ft by Saturday afternoon, then to 9,000-10,500 ft Saturday night. A broad trough easing southward gradually increases W winds on Sunday, bringing temperatures down a few degrees west of the Cascade Crest. The cooling will be delayed further east.
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
Friday
Night
Mild. A few high clouds early, then mostly clear.
Saturday
Very warm. Mostly sunny with a few wispy high clouds in the afternoon.
Friday
Night
Mild. Mostly clear.
Saturday
Very warm. Mostly sunny with a few wispy high clouds in the afternoon.
Friday
Night
Mild. Mostly clear.
Saturday
Very warm. Mostly sunny to start, then filtered sunshine with increasing high clouds.
Friday
Night
Mild. Partly to mostly clear skies.
Saturday
Very warm. Filtered sunshine with high and mid-level clouds thickening in the afternoon.
Friday
Night
Mild. A few clouds early, then becoming mostly clear. Light ridgeline and W wind at the Pass.
Saturday
Very warm. Filtered sunshine with high and mid-level clouds thickening slightly in the afternoon. Light ridgeline and W wind at the Pass.
Friday
Night
Mild. A few clouds early, then becoming mostly clear. Light ridgeline and W wind at the Pass.
Saturday
Very warm. Filtered sunshine with high and mid-level clouds thickening slightly in the afternoon. Light ridgeline and W wind at the Pass.
Friday
Night
Mild. Mostly clear. Shallow inversions in the valleys.
Saturday
Very warm. Mostly sunny in the morning with increasing high clouds in the afternoon.
Friday
Night
Mild. A few thin clouds in the evening, then becoming mostly clear.
Saturday
Very warm. Sunny to start with filtered sunshine developing as high clouds thicken throughout the day.
Friday
Night
Mild. Mostly clear with a few high clouds.
Saturday
Very warm. Filtered sunshine in the morning with obscured skies in the afternoon. A slight chance of an afternoon shower in the southern part.
Friday
Night
Mild. Decreasing high clouds.
Saturday
Very warm. Filtered sunshine in the morning with obscured skies and a chance of a shower or isolated thunderstorm in the afternoon.
Issued: 2:41 PM PDT Friday, April 12, 2024
Precipitation (in)
Friday Night
Saturday
Saturday Night
Sunday
5 pm - 5 am
5 am - 5 pm
5 pm - 5 am
5 am - 5 pm
Hurricane Ridge
0
0
0
0
Mt Baker Ski Area
0
0
0
0
Mt. Loop - Barlow Pass
0
0
0
0
Stevens Pass
0
0
0
0
Snoqualmie Pass
0
0
0
0
Crystal Mt
0
0
0
0
Paradise
0
0
0
0
White Pass
0
0
0
0
Washington Pass
0
0
0
0
Mission Ridge
0
0
0
0
Salmon la Sac - Gallagher Head
0
0
0
0
Tieton River - Darland Mt.
0
0
0
0
Mt Hood Meadows
0
0
LT 0.10
0
Timberline
0
LT 0.10
LT 0.10
0
Hurricane Ridge
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Mt Baker Ski Area
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Mt. Loop - Barlow Pass
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Stevens Pass
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Snoqualmie Pass
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Crystal Mt
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Paradise
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
White Pass
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Washington Pass
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Mission Ridge
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Salmon la Sac - Gallagher Head
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Tieton River - Darland Mt.
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
0
Sunday
0
Mt Hood Meadows
Precipitation (in)
Friday Night
0
Saturday
0
Saturday Night
LT 0.10
Sunday
0
Timberline
Precipitation (in)
Friday Night
0
Saturday
LT 0.10
Saturday Night
LT 0.10
Sunday
0
Issued: 2:41 PM PDT Friday, April 12, 2024
Snow Level (ft)
Friday
Evening
Friday
Night
Saturday
Morning
Saturday
Afternoon
Saturday
Evening
Saturday
Night
Sunday
Morning
Sunday
Afternoon
Olympics
7000'
7500'
8000'
8500'
9000'
9500'
9500'
8500'
West North
7000'
6000'
7500'
8500'
8500'
8500'
8500'
8500'
West Central
7500'
7500'
8000'
9000'
9000'
10000'
10000'
8500'
West South
8000'
8000'
9000'
9500'
10000'
10500'
10500'
9500'
Stevens Pass
7500'
7000'
7500'
9000'
9500'
10000'
10500'
9500'
Snoqualmie Pass
7500'
8000'
8500'
9500'
9500'
10500'
10500'
9500'
East North
6500'
5500'
7000'
9000'
9000'
9000'
9000'
9500'
East Central
8000'
8500'
9000'
9500'
10000'
10500'
10500'
10000'
East South
8500'
8500'
9000'
9500'
10000'
10500'
10500'
10500'
Mt. Hood
8500'
9500'
9500'
9000'
9000'
9000'
10000'
10000'
Olympics
Elevation
Friday
Evening
7000'
Friday
Night
7500'
Saturday
Morning
8000'
Saturday
Afternoon
8500'
Saturday
Evening
9000'
Saturday
Night
9500'
Sunday
Morning
9500'
Sunday
Afternoon
8500'
West North
Elevation
Friday
Evening
7000'
Friday
Night
6000'
Saturday
Morning
7500'
Saturday
Afternoon
8500'
Saturday
Evening
8500'
Saturday
Night
8500'
Sunday
Morning
8500'
Sunday
Afternoon
8500'
West Central
Elevation
Friday
Evening
7500'
Friday
Night
7500'
Saturday
Morning
8000'
Saturday
Afternoon
9000'
Saturday
Evening
9000'
Saturday
Night
10000'
Sunday
Morning
10000'
Sunday
Afternoon
8500'
West South
Elevation
Friday
Evening
8000'
Friday
Night
8000'
Saturday
Morning
9000'
Saturday
Afternoon
9500'
Saturday
Evening
10000'
Saturday
Night
10500'
Sunday
Morning
10500'
Sunday
Afternoon
9500'
Stevens Pass
Elevation
Friday
Evening
7500'
Friday
Night
7000'
Saturday
Morning
7500'
Saturday
Afternoon
9000'
Saturday
Evening
9500'
Saturday
Night
10000'
Sunday
Morning
10500'
Sunday
Afternoon
9500'
Snoqualmie Pass
Elevation
Friday
Evening
7500'
Friday
Night
8000'
Saturday
Morning
8500'
Saturday
Afternoon
9500'
Saturday
Evening
9500'
Saturday
Night
10500'
Sunday
Morning
10500'
Sunday
Afternoon
9500'
East North
Elevation
Friday
Evening
6500'
Friday
Night
5500'
Saturday
Morning
7000'
Saturday
Afternoon
9000'
Saturday
Evening
9000'
Saturday
Night
9000'
Sunday
Morning
9000'
Sunday
Afternoon
9500'
East Central
Elevation
Friday
Evening
8000'
Friday
Night
8500'
Saturday
Morning
9000'
Saturday
Afternoon
9500'
Saturday
Evening
10000'
Saturday
Night
10500'
Sunday
Morning
10500'
Sunday
Afternoon
10000'
East South
Elevation
Friday
Evening
8500'
Friday
Night
8500'
Saturday
Morning
9000'
Saturday
Afternoon
9500'
Saturday
Evening
10000'
Saturday
Night
10500'
Sunday
Morning
10500'
Sunday
Afternoon
10500'
Mt. Hood
Elevation
Friday
Evening
8500'
Friday
Night
9500'
Saturday
Morning
9500'
Saturday
Afternoon
9000'
Saturday
Evening
9000'
Saturday
Night
9000'
Sunday
Morning
10000'
Sunday
Afternoon
10000'
Issued: 2:41 PM PDT Friday, April 12, 2024
5000' Temperatures (°F)
Friday
Night
Saturday
Max / Min
Max / Min
Olympics
38 / 33
49 / 36
West North
42 / 36
48 / 36
West Central
42 / 38
50 / 39
West South
48 / 38
55 / 40
Stevens Pass
47 / 38
54 / 39
Snoqualmie Pass
43 / 38
50 / 40
East North
46 / 36
52 / 36
East Central
48 / 38
52 / 39
East South
47 / 37
55 / 39
Mt. Hood
43 / 39
54 / 43
Olympics
5000' Temperature Forecast (Max / Min)
Friday
Night
38 / 33
Saturday
49 / 36
West North
5000' Temperature Forecast (Max / Min)
Friday
Night
42 / 36
Saturday
48 / 36
West Central
5000' Temperature Forecast (Max / Min)
Friday
Night
42 / 38
Saturday
50 / 39
West South
5000' Temperature Forecast (Max / Min)
Friday
Night
48 / 38
Saturday
55 / 40
Stevens Pass
5000' Temperature Forecast (Max / Min)
Friday
Night
47 / 38
Saturday
54 / 39
Snoqualmie Pass
5000' Temperature Forecast (Max / Min)
Friday
Night
43 / 38
Saturday
50 / 40
East North
5000' Temperature Forecast (Max / Min)
Friday
Night
46 / 36
Saturday
52 / 36
East Central
5000' Temperature Forecast (Max / Min)
Friday
Night
48 / 38
Saturday
52 / 39
East South
5000' Temperature Forecast (Max / Min)
Friday
Night
47 / 37
Saturday
55 / 39
Mt. Hood
5000' Temperature Forecast (Max / Min)
Friday
Night
43 / 39
Saturday
54 / 43
Issued: 2:41 PM PDT Friday, April 12, 2024
Ridgeline Winds (mph)
Friday
Evening
Friday
Night
Saturday
Morning
Saturday
Afternoon
Olympics
ENE 0-10
SW 0-10
SW 0-10
WSW 0-10
West North
SSW 0-10
SW 0-10
SSW 0-10
SW 0-10
West Central
ENE 0-10
S 0-10
SSW 0-10
WSW 5-15
West South
E 0-10
SSW 0-10
SW 0-10
WNW 0-10
Stevens Pass
SE 0-10
SSW 0-10
SW 0-10
W 5-15
Snoqualmie Pass
ESE 0-10
ESE 0-10
SSW 0-10
W 5-15
East North
WSW 0-10
WSW 0-10
SW 0-10
WSW 5-15
East Central
S 0-10
SW 0-10
WSW 5-15
W 5-15
East South
ESE 0-10
SSW 0-10
SSW 0-10
S 0-10
Mt. Hood
SSW 5-15
SSW 10-20
S 5-15
NE 0-10
Olympics
Ridgeline Winds (mph)
Friday
Evening
ENE
0-10
Friday
Night
SW
0-10
Saturday
Morning
SW
0-10
Saturday
Afternoon
WSW
0-10
West North
Ridgeline Winds (mph)
Friday
Evening
SSW
0-10
Friday
Night
SW
0-10
Saturday
Morning
SSW
0-10
Saturday
Afternoon
SW
0-10
West Central
Ridgeline Winds (mph)
Friday
Evening
ENE
0-10
Friday
Night
S
0-10
Saturday
Morning
SSW
0-10
Saturday
Afternoon
WSW
5-15
West South
Ridgeline Winds (mph)
Friday
Evening
E
0-10
Friday
Night
SSW
0-10
Saturday
Morning
SW
0-10
Saturday
Afternoon
WNW
0-10
Stevens Pass
Ridgeline Winds (mph)
Friday
Evening
SE
0-10
Friday
Night
SSW
0-10
Saturday
Morning
SW
0-10
Saturday
Afternoon
W
5-15
Snoqualmie Pass
Ridgeline Winds (mph)
Friday
Evening
ESE
0-10
Friday
Night
ESE
0-10
Saturday
Morning
SSW
0-10
Saturday
Afternoon
W
5-15
East North
Ridgeline Winds (mph)
Friday
Evening
WSW
0-10
Friday
Night
WSW
0-10
Saturday
Morning
SW
0-10
Saturday
Afternoon
WSW
5-15
East Central
Ridgeline Winds (mph)
Friday
Evening
S
0-10
Friday
Night
SW
0-10
Saturday
Morning
WSW
5-15
Saturday
Afternoon
W
5-15
East South
Ridgeline Winds (mph)
Friday
Evening
ESE
0-10
Friday
Night
SSW
0-10
Saturday
Morning
SSW
0-10
Saturday
Afternoon
S
0-10
Mt. Hood
Ridgeline Winds (mph)
Friday
Evening
SSW
5-15
Friday
Night
SSW
10-20
Saturday
Morning
S
5-15
Saturday
Afternoon
NE
0-10
Issued: 2:41 PM PDT Friday, April 12, 2024
Extended Weather Synopsis
More significant cooling arrives Sunday night as a broad closed low passes to our north and brings a trough into our region. Very light rain and snow showers starting up in the early morning hours on Monday for the west slopes of the Cascades. Rain and snow showers peak Monday and Monday night. Snow levels should be in the 3000-4000 ft range, a marked departure from the unseasonably warm weather over the weekend. Expect chances of moderate to occasionally strong ridgeline winds along the east slopes of the Cascades.
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).