Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k
Weather Synopsis for Friday & Tuesday
A significant atmospheric river event is well underway in the Pacific Northwest. After bringing 1-4" of precipitable water for most NWAC stations in the Olympic Mountains and near and west of the Cascade Crest Thursday night, we expect another 1.5-5.5 inches for these same locations over the next 48 hours. Snow levels jumped above Crystal Base, Paradise, Snoqualmie and to around Stevens Pass level overnight on Thursday and these elevated snow levels should sustain during the day Friday as moisture continues to stream into the region on a SSW flow. Snow levels are likely to fluctuate near or below Mt. Baker base on Friday and a rain/snow mix is expected for Stevens Pass. Snow levels may drop slightly during the day on Thursday at Hurricane Ridge. North Cascade valley locations east of the Cascades may maintain snow through the morning, but there is a good chance of a changeover to rain or freezing rain in the afternoon.
The frontal zone takes on a slightly more N-S orientation by Saturday morning and the precipitation should gradually decrease through Saturday from the very intense rates we are seeing Friday morning. On Saturday, the precipitation also shifts east with some cooling as a trough shifts into the region from the west.
Winds should be strong on Friday and gradually decrease Friday night and Saturday.
Weather Forecast
Hurricane Ridge
| Friday | Moderate rain and snow. Slight cooling during the day. |
Mt. Baker
| Friday | Heavy rain and snow. |
Washington Pass and Leavenworth
| Friday | Heavy snow at Washington Pass. A mix of moderate to heavy rain in Leavenworth. Moderate to heavy snow may transition to freezing rain or all rain. by afternoon. Strong 5000 ft winds. |
Stevens and Snoqualmie Pass
| Friday | Heavy rain and snow. Rain at Snoqualmie and a rain/snow mix at Stevens Pass levels. Strong 5000 ft winds. |
Mt. Rainier, Crystal and White Pass
| Friday | Heavy rain and upper-elevation snow. Rain at Crystal and Paradise levels. Strong 5000 ft winds. |
Mt. Hood
| Friday | Periods of light rain. Mild. Strong 5000 ft winds. |
Issued: 7:46 AM PST Friday, December 20, 2019
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Friday Morning | Snow Level | 4000' | 4000' | 4000' | 5500' | 4500' | 5500' | 5500' | 6000' |
| Friday Afternoon | Snow Level | 4000' | 3500' | 4500' | 5500' | 4500' | 5500' | 5500' | 6000' |
| Friday Evening | Snow Level * | 4000' | 4000' | 4500' | 5000' | 5000' | 5000' | 5500' | 6500' |
| Friday Night | Snow Level * | 3500' | 4000' | 4500' | 5500' | 5000' | 5000' | 5500' | 6500' |
| Saturday Morning | Snow Level | 3000' | 3500' | 4500' | 5000' | 4500' | 4500' | 5000' | 5500' |
| Saturday Afternoon | Snow Level | 3000' | 3000' | 4500' | 5500' | 3500' | 3500' | 3500' | 4500' |
| Hurricane Ridge | Elevation |
|---|---|
| Friday Morning |
Snow Level 4000' |
| Friday Afternoon |
Snow Level 4000' |
| Friday Evening |
Snow Level 4000' (Easterly Flow *) |
| Friday Night |
Snow Level 3500' (Easterly Flow *) |
| Saturday Morning |
Snow Level 3000' |
| Saturday Afternoon |
Snow Level 3000' |
| Mt. Baker | Elevation |
|---|---|
| Friday Morning |
Snow Level 4000' |
| Friday Afternoon |
Snow Level 3500' |
| Friday Evening |
Snow Level 4000' (Easterly Flow *) |
| Friday Night |
Snow Level 4000' (Easterly Flow *) |
| Saturday Morning |
Snow Level 3500' |
| Saturday Afternoon |
Snow Level 3000' |
| Washington Pass | Elevation |
|---|---|
| Friday Morning |
Snow Level 4000' |
| Friday Afternoon |
Snow Level 4500' |
| Friday Evening |
Snow Level 4500' (Easterly Flow *) |
| Friday Night |
Snow Level 4500' (Easterly Flow *) |
| Saturday Morning |
Snow Level 4500' |
| Saturday Afternoon |
Snow Level 4500' |
| Leavenworth | Elevation |
|---|---|
| Friday Morning |
Snow Level 5500' |
| Friday Afternoon |
Snow Level 5500' |
| Friday Evening |
Snow Level 5000' (Easterly Flow *) |
| Friday Night |
Snow Level 5500' (Easterly Flow *) |
| Saturday Morning |
Snow Level 5000' |
| Saturday Afternoon |
Snow Level 5500' |
| Stevens Pass | Elevation |
|---|---|
| Friday Morning |
Snow Level 4500' |
| Friday Afternoon |
Snow Level 4500' |
| Friday Evening |
Snow Level 5000' (Easterly Flow *) |
| Friday Night |
Snow Level 5000' (Easterly Flow *) |
| Saturday Morning |
Snow Level 4500' |
| Saturday Afternoon |
Snow Level 3500' |
| Snoqualmie Pass | Elevation |
|---|---|
| Friday Morning |
Snow Level 5500' |
| Friday Afternoon |
Snow Level 5500' |
| Friday Evening |
Snow Level 5000' (Easterly Flow *) |
| Friday Night |
Snow Level 5000' (Easterly Flow *) |
| Saturday Morning |
Snow Level 4500' |
| Saturday Afternoon |
Snow Level 3500' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Friday Morning |
Snow Level 5500' |
| Friday Afternoon |
Snow Level 5500' |
| Friday Evening |
Snow Level 5500' (Easterly Flow *) |
| Friday Night |
Snow Level 5500' (Easterly Flow *) |
| Saturday Morning |
Snow Level 5000' |
| Saturday Afternoon |
Snow Level 3500' |
| Mt. Hood | Elevation |
|---|---|
| Friday Morning |
Snow Level 6000' |
| Friday Afternoon |
Snow Level 6000' |
| Friday Evening |
Snow Level 6500' (Easterly Flow *) |
| Friday Night |
Snow Level 6500' (Easterly Flow *) |
| Saturday Morning |
Snow Level 5500' |
| Saturday Afternoon |
Snow Level 4500' |
* Easterly flow in the Cascade Passes can cause locally lower Snow or Freezing levels than areas further west.
Freezing Level is when no precipitation is forecast.
Precipitation Forecast
| Friday | Friday Night | Tuesday | |
|---|---|---|---|
| 4 am - 4 pm | 4 pm - 4 am | 4 am - 4 pm | |
| Hurricane Ridge | 0.50 - 0.75 | 0.50 - 0.75 | 0.25 |
| Mt Baker Ski Area | 1.00 | 1.50 | 0.50 |
| Washington Pass | 1.00 | 0.75 | 0.25 - 0.50 |
| Leavenworth | 0.50 | 0.25 | LT 0.10 |
| Stevens Pass | 1.00 - 1.50 | 0.50 | 0.50 |
| Snoqualmie Pass | 1.50 | 0.75 | 0.25 - 0.50 |
| Mission Ridge | 0.25 | 0.25 | LT 0.25 |
| Crystal Mt | 2.00 | 1.50 | 0.25 - 0.50 |
| Paradise | 2.50 | 1.50 - 2.00 | 0.75 |
| White Pass | 0.75 -1.00 | 0.50 - 0.75 | 0.25 - 0.50 |
| Mt Hood Meadows | 0.25 | LT 0.10 | 0.50 |
| Timberline | 0.25 | LT 0.10 | 0.50 |
| Hurricane Ridge | Precipitation Forecast |
|---|---|
| Friday | 0.50 - 0.75 |
| Friday Night | 0.50 - 0.75 |
| Tuesday | 0.25 |
| Mt Baker Ski Area | Precipitation Forecast |
|---|---|
| Friday | 1.00 |
| Friday Night | 1.50 |
| Tuesday | 0.50 |
| Washington Pass | Precipitation Forecast |
|---|---|
| Friday | 1.00 |
| Friday Night | 0.75 |
| Tuesday | 0.25 - 0.50 |
| Leavenworth | Precipitation Forecast |
|---|---|
| Friday | 0.50 |
| Friday Night | 0.25 |
| Tuesday | LT 0.10 |
| Stevens Pass | Precipitation Forecast |
|---|---|
| Friday | 1.00 - 1.50 |
| Friday Night | 0.50 |
| Tuesday | 0.50 |
| Snoqualmie Pass | Precipitation Forecast |
|---|---|
| Friday | 1.50 |
| Friday Night | 0.75 |
| Tuesday | 0.25 - 0.50 |
| Mission Ridge | Precipitation Forecast |
|---|---|
| Friday | 0.25 |
| Friday Night | 0.25 |
| Tuesday | LT 0.25 |
| Crystal Mt | Precipitation Forecast |
|---|---|
| Friday | 2.00 |
| Friday Night | 1.50 |
| Tuesday | 0.25 - 0.50 |
| Paradise | Precipitation Forecast |
|---|---|
| Friday | 2.50 |
| Friday Night | 1.50 - 2.00 |
| Tuesday | 0.75 |
| White Pass | Precipitation Forecast |
|---|---|
| Friday | 0.75 -1.00 |
| Friday Night | 0.50 - 0.75 |
| Tuesday | 0.25 - 0.50 |
| Mt Hood Meadows | Precipitation Forecast |
|---|---|
| Friday | 0.25 |
| Friday Night | LT 0.10 |
| Tuesday | 0.50 |
| Timberline | Precipitation Forecast |
|---|---|
| Friday | 0.25 |
| Friday Night | LT 0.10 |
| Tuesday | 0.50 |
LT = less than; WE or Water equivalent is the liquid water equivalent of melted snow in hundredths of inches. As a rough approximation 1 inch of snow = about .10 inches WE, or 10 inches of snow = about 1 inch WE.
Issued: 7:46 AM PST Friday, December 20, 2019
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Friday Morning | SW 5 - 15 | SSW 10 - 20 | SW 25 - 35 | SW 25 - 35 | SW 40 - 60 |
| Friday Afternoon | S 5 - 15 | SSE 15 - 25 | SW 30 - 40 | SW 30 - 40 | SW 35 - 45 |
| Friday Evening | SW 5 - 15 | SSW 15 - 25 | SSW 20 - 30 | SSW 20 - 30 | SSW 30 - 40 |
| Friday Night | W 5 - 15 | SW 5 - 15 | SSW 10 - 20 | SW 10 - 20 | SW 20 - 30 |
| Saturday Morning | W 5 - 15 | WSW 0 - 10 | W 5 - 15 | SW 5 - 15 | SW 15 - 25 |
| Saturday Afternoon | SW 5 - 15 | WSW 0 - 10 | W 5 - 15 | W 5 - 15 | W 10 - 20 |
| Hurricane Ridge | Elevation |
|---|---|
| Friday Morning | SW 5 - 15 |
| Friday Afternoon | S 5 - 15 |
| Friday Evening | SW 5 - 15 |
| Friday Night | W 5 - 15 |
| Saturday Morning | W 5 - 15 |
| Saturday Afternoon | SW 5 - 15 |
| Mt. Baker | Elevation |
|---|---|
| Friday Morning | SSW 10 - 20 |
| Friday Afternoon | SSE 15 - 25 |
| Friday Evening | SSW 15 - 25 |
| Friday Night | SW 5 - 15 |
| Saturday Morning | WSW 0 - 10 |
| Saturday Afternoon | WSW 0 - 10 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Friday Morning | SW 25 - 35 |
| Friday Afternoon | SW 30 - 40 |
| Friday Evening | SSW 20 - 30 |
| Friday Night | SSW 10 - 20 |
| Saturday Morning | W 5 - 15 |
| Saturday Afternoon | W 5 - 15 |
| Mt. Rainier | Elevation |
|---|---|
| Friday Morning | SW 25 - 35 |
| Friday Afternoon | SW 30 - 40 |
| Friday Evening | SSW 20 - 30 |
| Friday Night | SW 10 - 20 |
| Saturday Morning | SW 5 - 15 |
| Saturday Afternoon | W 5 - 15 |
| Mt. Hood | Elevation |
|---|---|
| Friday Morning | SW 40 - 60 |
| Friday Afternoon | SW 35 - 45 |
| Friday Evening | SSW 30 - 40 |
| Friday Night | SW 20 - 30 |
| Saturday Morning | SW 15 - 25 |
| Saturday Afternoon | W 10 - 20 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Friday Morning | SW 5 - 15 |
| Friday Afternoon | S 5 - 15 |
| Friday Evening | SW 5 - 15 |
| Friday Night | W 5 - 15 |
| Saturday Morning | W 5 - 15 |
| Saturday Afternoon | SW 5 - 15 |
| Mt. Baker | Direction - Speed |
|---|---|
| Friday Morning | SSW 10 - 20 |
| Friday Afternoon | SSE 15 - 25 |
| Friday Evening | SSW 15 - 25 |
| Friday Night | SW 5 - 15 |
| Saturday Morning | WSW 0 - 10 |
| Saturday Afternoon | WSW 0 - 10 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Friday Morning | SW 25 - 35 |
| Friday Afternoon | SW 30 - 40 |
| Friday Evening | SSW 20 - 30 |
| Friday Night | SSW 10 - 20 |
| Saturday Morning | W 5 - 15 |
| Saturday Afternoon | W 5 - 15 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Friday Morning | SW 25 - 35 |
| Friday Afternoon | SW 30 - 40 |
| Friday Evening | SSW 20 - 30 |
| Friday Night | SW 10 - 20 |
| Saturday Morning | SW 5 - 15 |
| Saturday Afternoon | W 5 - 15 |
| Mt. Hood | Direction - Speed |
|---|---|
| Friday Morning | SW 40 - 60 |
| Friday Afternoon | SW 35 - 45 |
| Friday Evening | SSW 30 - 40 |
| Friday Night | SW 20 - 30 |
| Saturday Morning | SW 15 - 25 |
| Saturday Afternoon | W 10 - 20 |
Directions above indicate the direction the wind blows from on the 16-point cardinal scale. These winds indicate "free" winds, or those winds in the atmosphere not influenced by terrain. Topographical effects may produce greater or lower wind speeds in certain locations as well as significant variations in direction.
Free Winds at 9000' (mph)
| Mt. Baker | Washington Pass | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Friday Morning | SW 30 - 40 | SW 40 - 50 | SW 55 - 75 | SW 60 - 80 | WSW 65 - 85 |
| Friday Afternoon | SW 35 - 45 | WSW 40 - 50 | WSW 55 - 75 | WSW 55 - 75 | WSW 60 - 80 |
| Friday Evening | SSW 35 - 45 | SW 40 - 55 | SW 55 - 75 | SW 55 - 75 | SW 50 - 70 |
| Friday Night | SSW 25 - 35 | SW 25 - 35 | SW 50 - 70 | SW 50 - 70 | SW 65 - 85 |
| Saturday Morning | SW 10 - 20 | SW 10 - 20 | SW 25 - 35 | SW 25 - 35 | SW 55 - 75 |
| Saturday Afternoon | W 10 - 20 | W 10 - 20 | W 20 - 30 | W 20 - 30 | WSW 30 - 40 |
| Mt. Baker | Direction - Speed |
|---|---|
| Friday Morning | SW 30 - 40 |
| Friday Afternoon | SW 35 - 45 |
| Friday Evening | SSW 35 - 45 |
| Friday Night | SSW 25 - 35 |
| Saturday Morning | SW 10 - 20 |
| Saturday Afternoon | W 10 - 20 |
| Washington Pass | Direction - Speed |
|---|---|
| Friday Morning | SW 40 - 50 |
| Friday Afternoon | WSW 40 - 50 |
| Friday Evening | SW 40 - 55 |
| Friday Night | SW 25 - 35 |
| Saturday Morning | SW 10 - 20 |
| Saturday Afternoon | W 10 - 20 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Friday Morning | SW 55 - 75 |
| Friday Afternoon | WSW 55 - 75 |
| Friday Evening | SW 55 - 75 |
| Friday Night | SW 50 - 70 |
| Saturday Morning | SW 25 - 35 |
| Saturday Afternoon | W 20 - 30 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Friday Morning | SW 60 - 80 |
| Friday Afternoon | WSW 55 - 75 |
| Friday Evening | SW 55 - 75 |
| Friday Night | SW 50 - 70 |
| Saturday Morning | SW 25 - 35 |
| Saturday Afternoon | W 20 - 30 |
| Mt. Hood | Direction - Speed |
|---|---|
| Friday Morning | WSW 65 - 85 |
| Friday Afternoon | WSW 60 - 80 |
| Friday Evening | SW 50 - 70 |
| Friday Night | SW 65 - 85 |
| Saturday Morning | SW 55 - 75 |
| Saturday Afternoon | WSW 30 - 40 |
Directions above indicate the direction the wind blows from on the 16-point cardinal scale. These winds indicate "free" winds, or those winds in the atmosphere not influenced by terrain. Topographical effects may produce greater or lower wind speeds in certain locations as well as significant variations in direction.
Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k
Previous forecast from Dec 19, 2019
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.