Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Friday & Monday
A deep upper trough and associated closed low will migrate from the southern Oregon/northern California coast inland on Friday with a cool and slightly unstable air mass over our region. A organized band of showers rotating north of the low and moving from east to west is affecting the Mt. Hood area and the far southern Washington Cascades. Over the Olympics and over the rest of the Cascades, afternoon cumulus is building in the slightly unstable air mass. Isolated showers may develop later this afternoon.
Freezing levels will climb to 5000-6000 feet today, but snow levels will quickly plummet during any shower activity. NWAC stations near or below 3000' are pushing 50 degrees in the Washington Cascades this afternoon. Any shower activity that does develop will wane in the evening.
Onshore flow on Saturday will increase low level moisture and clouds along the Olympics and West Slopes of the Cascades as well as lower snow/freezing levels a notch. This should also increase cloud cover earlier in the day. Any light shower activity will again quickly diminish Saturday night.
Weather Forecast
Olympics
| Friday | Partly to mostly clear becoming mostly cloudy with scattered showers. |
| Friday Night | Slight chance of an evening shower. Partly to mostly cloudy. |
| Saturday | Mostly cloudy with isolated afternoon showers. |
| Saturday Night | Partly to mostly cloudy. |
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
| Friday | North Cascades: Mostly clear becoming partly to mostly cloudy in the afternoon with a slight chance of a shower. Central and South Cascades: Partly to mostly clear becoming mostly cloudy with isolated afternoon showers, especially southwest Cascades. |
| Friday Night | Slight chance of an evening shower southwest Cascades. Partly to mostly cloudy. |
| Saturday | Mostly cloudy with isolated afternoon showers. |
| Saturday Night | Partly to mostly cloudy. |
East Slopes of the Washington Cascades
| Friday | Northeast and central-east Cascades: Partly to mostly clear becoming partly to mostly cloudy in the afternoon with isolated showers near the Cascade crest. Southeast Cascades: Partly to mostly cloudy becoming mostly cloudy with scattered showers in the afternoon. |
| Friday Night | Slight chance of an evening shower near the Cascade crest. Partly cloudy. |
| Saturday | Partly to mostly cloudy with isolated afternoon showers near the Cascade crest. |
| Saturday Night | Partly to mostly clear. |
Mt. Hood
| Friday | Cloudy with scattered showers. |
| Friday Night | Slight chance of an evening shower. Partly to mostly cloudy. |
| Saturday | Mostly cloudy with scattered showers, increasing in the afternoon. |
| Saturday Night | Mostly cloudy with scattered showers, decreasing after midnight. |
Issued: 2:18 PM PDT Friday, March 16, 2018
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Friday Afternoon | Snow Level | 4000' | 4500' | 4500' | ' | ' | 4500' | ' | 3500' |
| Friday Night | Snow Level | 4000' | 2000' | 1000' | ' | ' | 2000' | ' | 3500' |
| Saturday Morning | Snow Level | 4000' | 2000' | 1000' | ' | ' | 2000' | ' | 3500' |
| Saturday Afternoon | Snow Level | 3500' | 4000' | 4500' | ' | ' | 4000' | ' | 3500' |
| Saturday Night | Snow Level | 2500' | 2500' | 2500' | ' | ' | 2500' | ' | 2000' |
| Hurricane Ridge | Elevation |
|---|---|
| Friday Afternoon |
Snow Level 4000' |
| Friday Night |
Snow Level 4000' |
| Saturday Morning |
Snow Level 4000' |
| Saturday Afternoon |
Snow Level 3500' |
| Saturday Night |
Snow Level 2500' |
| Mt. Baker | Elevation |
|---|---|
| Friday Afternoon |
Snow Level 4500' |
| Friday Night |
Snow Level 2000' |
| Saturday Morning |
Snow Level 2000' |
| Saturday Afternoon |
Snow Level 4000' |
| Saturday Night |
Snow Level 2500' |
| Washington Pass | Elevation |
|---|---|
| Friday Afternoon |
Snow Level 4500' |
| Friday Night |
Snow Level 1000' |
| Saturday Morning |
Snow Level 1000' |
| Saturday Afternoon |
Snow Level 4500' |
| Saturday Night |
Snow Level 2500' |
| Leavenworth | Elevation |
|---|---|
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Saturday Morning |
Snow Level ' |
| Saturday Afternoon |
Snow Level ' |
| Saturday Night |
Snow Level ' |
| Stevens Pass | Elevation |
|---|---|
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Saturday Morning |
Snow Level ' |
| Saturday Afternoon |
Snow Level ' |
| Saturday Night |
Snow Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Friday Afternoon |
Snow Level 4500' |
| Friday Night |
Snow Level 2000' |
| Saturday Morning |
Snow Level 2000' |
| Saturday Afternoon |
Snow Level 4000' |
| Saturday Night |
Snow Level 2500' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Friday Afternoon |
Snow Level ' |
| Friday Night |
Snow Level ' |
| Saturday Morning |
Snow Level ' |
| Saturday Afternoon |
Snow Level ' |
| Saturday Night |
Snow Level ' |
| Mt. Hood | Elevation |
|---|---|
| Friday Afternoon |
Snow Level 3500' |
| Friday Night |
Snow Level 3500' |
| Saturday Morning |
Snow Level 3500' |
| Saturday Afternoon |
Snow Level 3500' |
| Saturday Night |
Snow Level 2000' |
* 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
| Monday | Monday | |
|---|---|---|
| Hurricane Ridge | LT 0.10 | LT 0.10 |
| Mt Baker Ski Area | LT 0.10 | LT 0.10 |
| Washington Pass | LT 0.10 | LT 0.10 |
| Stevens Pass | LT 0.10 | LT 0.25 |
| Snoqualmie Pass | LT 0.10 | LT 0.25 |
| Mission Ridge | LT 0.10 | LT 0.10 |
| Crystal Mt | LT 0.10 | LT 0.25 |
| Paradise | LT 0.10 | LT 0.25 |
| White Pass | LT 0.10 | LT 0.10 |
| Mt Hood Meadows | LT 0.25 | LT 0.10 |
| Timberline | LT 0.25 | LT 0.25 |
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: 2:18 PM PDT Friday, March 16, 2018
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Friday Afternoon | NE 5 - 15 | N 0 - 10 | NW 0 - 10 | --- - | NE 5 - 15 |
| Friday Night | N 0 - 10 | N 0 - 10 | NW 0 - 10 | --- - | NW 0 - 10 |
| Saturday Morning | W 0 - 10 | N 0 - 10 | W 5 - 15 | --- - | W 10 - 20 |
| Saturday Afternoon | W 0 - 10 | W 0 - 10 | W 5 - 15 | --- - | W 10 - 20 |
| Saturday Night | W 0 - 10 | W 0 - 10 | W 5 - 15 | --- - | W 10 - 20 |
| Hurricane Ridge | Elevation |
|---|---|
| Friday Afternoon | NE 5 - 15 |
| Friday Night | N 0 - 10 |
| Saturday Morning | W 0 - 10 |
| Saturday Afternoon | W 0 - 10 |
| Saturday Night | W 0 - 10 |
| Mt. Baker | Elevation |
|---|---|
| Friday Afternoon | N 0 - 10 |
| Friday Night | N 0 - 10 |
| Saturday Morning | N 0 - 10 |
| Saturday Afternoon | W 0 - 10 |
| Saturday Night | W 0 - 10 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Friday Afternoon | NW 0 - 10 |
| Friday Night | NW 0 - 10 |
| Saturday Morning | W 5 - 15 |
| Saturday Afternoon | W 5 - 15 |
| Saturday Night | W 5 - 15 |
| Mt. Rainier | Elevation |
|---|---|
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Saturday Morning | --- - |
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Friday Afternoon | NE 5 - 15 |
| Friday Night | NW 0 - 10 |
| Saturday Morning | W 10 - 20 |
| Saturday Afternoon | W 10 - 20 |
| Saturday Night | W 10 - 20 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Friday Afternoon | NE 5 - 15 |
| Friday Night | N 0 - 10 |
| Saturday Morning | W 0 - 10 |
| Saturday Afternoon | W 0 - 10 |
| Saturday Night | W 0 - 10 |
| Mt. Baker | Direction - Speed |
|---|---|
| Friday Afternoon | N 0 - 10 |
| Friday Night | N 0 - 10 |
| Saturday Morning | N 0 - 10 |
| Saturday Afternoon | W 0 - 10 |
| Saturday Night | W 0 - 10 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Friday Afternoon | NW 0 - 10 |
| Friday Night | NW 0 - 10 |
| Saturday Morning | W 5 - 15 |
| Saturday Afternoon | W 5 - 15 |
| Saturday Night | W 5 - 15 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Saturday Morning | --- - |
| Saturday Afternoon | --- - |
| Saturday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Friday Afternoon | NE 5 - 15 |
| Friday Night | NW 0 - 10 |
| Saturday Morning | W 10 - 20 |
| Saturday Afternoon | W 10 - 20 |
| Saturday Night | 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 Afternoon | N 0 - 10 | NE 0 - 10 | NE 10 - 20 | --- - | NE 5 - 15 |
| Friday Night | N 0 - 10 | N 0 - 10 | N 5 - 15 | --- - | NNE 5 - 15 |
| Saturday | NW 5 - 15 | NW 5 - 15 | NW 10 - 20 | --- - | NW 10 - 20 |
| Saturday Night | N 5 - 15 | NW 5 - 15 | NW 5 - 15 | --- - | NW 10 - 20 |
| Mt. Baker | Direction - Speed |
|---|---|
| Friday Afternoon | N 0 - 10 |
| Friday Night | N 0 - 10 |
| Saturday | NW 5 - 15 |
| Saturday Night | N 5 - 15 |
| Washington Pass | Direction - Speed |
|---|---|
| Friday Afternoon | NE 0 - 10 |
| Friday Night | N 0 - 10 |
| Saturday | NW 5 - 15 |
| Saturday Night | NW 5 - 15 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Friday Afternoon | NE 10 - 20 |
| Friday Night | N 5 - 15 |
| Saturday | NW 10 - 20 |
| Saturday Night | NW 5 - 15 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Friday Afternoon | --- - |
| Friday Night | --- - |
| Saturday | --- - |
| Saturday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Friday Afternoon | NE 5 - 15 |
| Friday Night | NNE 5 - 15 |
| Saturday | NW 10 - 20 |
| Saturday Night | NW 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.
Issued: 2:18 PM PDT Friday, March 16, 2018
Extended Weather Synopsis for Monday night through Monday
A secondary upper low will develop and spin off the Olympic Peninsula Sunday. A shortwave rotating out of the low will mainly increase the chance of organized showers over the Olympics. Cloud cover is still a toss-up for Mt. Hood and the Washington Cascades on Sunday, but in general an increase in afternoon clouds is a good bet. Snow/freezing levels will be the lower slightly on Sunday.
As the secondary low pressure system pulls further offshore Monday, upper level ridging should briefly build over the area leading to a drying trend. The ridge shifts inland Tuesday, leading to another dry day with rising freezing levels. High clouds may start to move into the area in advance of the next frontal system.
Extended Weather
Olympics, Washington Cascades and Mt. Hood Area
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Sunday | Snow Level | 3000' - 4000' | 2500' - 3500' | 2500' - 3500' | |
| Sunday Night | Freezing Level | 1000' - 2000' | 1000' - 2000' | 1500' - 2500' | |
| Monday | Freezing Level | 3500' - 4500' | 4500' - 5500' | 5000' - 6000' | |
| Monday Night | Freezing Level | 2500' - 3500' | 3500' - 4500' | 4500' - 5500' | |
| Tuesday | Freezing Level | 5500' - 6500' | 6000' - 7000' | 7000' - 8000' |
| Mt. Baker | Elevation |
|---|---|
| Sunday |
Snow Level 3000' - 4000' |
| Sunday Night |
Freezing Level 1000' - 2000' |
| Monday |
Freezing Level 3500' - 4500' |
| Monday Night |
Freezing Level 2500' - 3500' |
| Tuesday |
Freezing Level 5500' - 6500' |
| Snoqualmie Pass | Elevation |
|---|---|
| Sunday |
Snow Level 2500' - 3500' |
| Sunday Night |
Freezing Level 1000' - 2000' |
| Monday |
Freezing Level 4500' - 5500' |
| Monday Night |
Freezing Level 3500' - 4500' |
| Tuesday |
Freezing Level 6000' - 7000' |
| Mt. Hood | Elevation |
|---|---|
| Sunday |
Snow Level 2500' - 3500' |
| Sunday Night |
Freezing Level 1500' - 2500' |
| Monday |
Freezing Level 5000' - 6000' |
| Monday Night |
Freezing Level 4500' - 5500' |
| Tuesday |
Freezing Level 7000' - 8000' |
* 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.
Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Previous forecast from Mar 16, 2018
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.
Updated 9 AM: Corrected Synopsis