8:00 Start Sun April 21st no ABS

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time: 0700 Saturday  

This will be the final weather forecast of the 2019 season. John and Dan thank you for following along.  Have a great safe summer and we will do it all again next winter.  

Current Observations:

24hr Precipitation:        .51swe, 0” of snow

Temperature profile:     35 base, 32 ridge

Pass level winds:            light, westerly

Barometer:                    1012mb’s and rising

Sky:                               overcast

Radar:  the left over moisture is now heading out with dry conditions over the mountains and to the west. 

The Forecast:  The morning fog and clouds will dissipate today with drying and sunbreaks expected.  The temperatures will peak in the upper 40’s.  Hit repeat for tomorrow.   

Long Range:  Dry conditions will persist through most of Monday with rain likely for Tuesday and Wednesday.

  

The Science:  A high pressure ridge, now strengthening along the PNW coast, will drift east today. This will begin to stabilize the atmosphere and allow the clouds and morning fog to dissipate.  We should see some nice sunshine with temperatures in the upper 40’s today.  

The rising barometer will provide another sunny day tomorrow with more moisture moving in late Monday night.

Forecast confidence: Good.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .10   snow: 0 Tomorrow’s 24hr water: 0  snow: 0 Trend and Timing: Drying today.

Temperature: Low: 34  High: 48 Freezing level: 4500’ – 6000’ Trend and Timing:    Temperatures will rebound today with freezing levels quickly rising above 5000’.

Winds Base: 0-5 W Ridge Top:  0-10 WNW Trend and Timing: Light westerly flow will continue through the weekend.

8:00 Start Sat April 19th no ABS

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time:  Friday 0700

Current Observations:

24hr Precipitation:        .42swe, 0” of snow

Temperature profile:     44 base, 43 ridge

Pass level winds:            light and out of the west

Barometer:                    1013mb’s falling

Sky:                               OC

Radar: wide spread rain along the west slopes and throughout the greater Sound region

The Forecast: Rain ends tonight, dry with sun breaks for the weekend.

Long Range: Monday will be mostly dry with some rain expected on Tuesday. 

  

The Science: Moisture, out ahead of an approaching cold front, will produce a soggy day at Stevens Pass.  Once the cold front moves east of the crest tonight, temperatures will fall and the moisture will be cut off.  Cool, dry northerly flow associated with the approaching high pressure ridge will provide a tranquil final weekend of the season.

Forecast confidence: Good.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .5  snow: 0 Tomorrow’s 24hr water: .10  snow: 0 Trend and Timing: Drying begins this evening with tomorrow and Sunday being mostly dry.

Temperature: Low: 30  High: 44 Freezing level: 6000’ – 4000’ Trend and Timing:    Freezing levels will drop to 4000’ by early tomorrow morning and then bump back up to > 5000’ for the weekend.

Winds Base: 5-10 W Ridge Top: 5-10 NW Trend and Timing: Westerly flow at the surface with NW flow aloft will be the wind pattern through tomorrow.

8:00 Start Fri April 19th no ABS

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time:  Thursday 0800

Current Observations:

24hr Precipitation:        .18swe, 0 snow

Temperature profile:     37 base – 40 ridges

Pass level winds:            light, SW

Barometer:                    1022mb’s and falling

Sky:                               OC

Radar:  light rain falling at Stevens with a fairly large swath of moisture hitting the western slopes.

The Forecast:  Rain today with daytime temperatures reaching +-50^0f . Rain persist through tomorrow with freezing levels remaining at or above 5000’.

Long Range: The final weekend of the season will likely be dry and sunny.

  

The Science:  The leading warm front of an approaching triple point system will bring warm WSW flow into the region today.  The warm air advection is underway with the associated moisture just now entering the mountains.   Freezing levels will peak near 7500’.   The following cold front will swing through late tonight or early tomorrow morning.  Temperatures will fall in the wake of the cold front but not enough to produce snow below 5000’.

A high pressure ridge begins to build late Friday with clearing and cool northerly flow developing for the weekend. 

Forecast confidence:  Models are in agreement for the next 36-48hrs, so confidence is good.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .5-.75  snow: 0 Tomorrow’s 24hr water: .25-.5   snow: 0 Trend and Timing: Rain today and tomorrow.

Temperature: Low: 34  High: 50 Freezing level:  7500’ – 5500’ Trend and Timing:    Freezing levels peak > 7000’ this afternoon and then fall to +-5500’ after midnight.

Winds Base:  0-10 WSW Ridge Top: 5-15 SSW Trend and Timing: Southerly flow will shift westerly through the day.  Some periods of gusty ridge top winds can be expected.

MOUNTAIN WEATHER FORECAST

Day and Time:  Monday 0700

Current Observations:

24hr Precipitation:        .05swe, 1” of snow

Temperature profile:     28 base,  23 ridges

Pass level winds:            Light and out of the west

Barometer:                    1008mb’s and steady

Sky:                               high clouds with pass level fog

Radar: dry in the mountains with some moisture echo’s popping up over the coastal waters.

The Forecast:  Partly cloudy with temperature in the upper 30’s or even 40 today.   Mostly dry tomorrow with light mixed rain and snow moving in tomorrow night.

Long Range: Light rain on Wednesday with another push of moderate moisture on Thursday and Frida; which will likely be rain.   

  

The Science: I hope you were able to see the amazing alpenglow this morning.  

An upper-level high pressure ridge cut off the moisture sooner than expected yesterday.  The atmosphere stabilized overnight with mostly dry weather expected for the next 24-36hrs. 

A weak low pressure system, sliding down the coastline, will spin clouds and weak bands of moisture into the mountain beginning tomorrow evening.  Warm advection will accompany this counterclockwise rotation with freezing levels slowly rising.  Therefore, no significant snow accumulation is expected.

Forecast confidence: Good.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: 0  snow: 0 Tomorrow’s 24hr water: .25   snow: trace on upper mountain Trend and Timing: Dry conditions will persist through noon tomorrow with light precipitation developing tomorrow night.

Temperature: Low: 28  High: 40 Freezing level:  3000’ – 5000’ Trend and Timing:    Freezing levels will rise to 5000’ this afternoon with overnight temperatures struggling to drop below freezing.

Winds Base: 0-5 E Ridge Top: 0-10 E Trend and Timing: Light east flow will develop today and then shift back to WSW tomorrow.

8am Thursday, No ABS

Do not come to work on Monday. See you next season.

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time: Sunday 0700

Current Observations:

24hr Precipitation:        .64swe – 4” of snow

Temperature profile:     30f base,  24 ridge

Pass level winds:            gusty,  westerly

Barometer:                    1008mb’s and holding

Sky:                               OC

Radar:  Lightly snowing along the Cascade crest with dry conditions to the west and east.

The Forecast:  The snow will continue today with cool temperatures.  Tomorrow and Tuesday will be mostly dry with light rain possible on Wednesday.

Long Range:   Model opinions begin to split on Wednesday with some showing light rain and others showing clearing and high freezing levels.  All will be revealed in time.  

  

The Science:  A cold front moved through last night which is now moving into western Montana. Cool unstable westerly flow has filled in with nice orographics now pushing through the Passes.  Weak convergence zone(s) conditions are expected to persist today.   

A high pressure ridge will develop tonight which will cut off the moisture and produce cooling and clearing for tomorrow.  Seasonally warm air begins to creep back into the scene tomorrow; freezing levels by the end of the week could peak above 8000’ with daytime high temperatures in the 50’s.  

Forecast confidence: Good with changing convergence conditions dynamics in play.  Fair to poor for long range outlook.  

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .5 -.75  snow: 4-7 Tomorrow’s 24hr water: .10  snow: 0 Trend and Timing: Light to moderate snow will continue today and taper off after midnight tonight.  Tomorrow will be mostly dry.

Temperature: Low: 24  High: 32 Freezing level: +-4000’ Trend and Timing:    Freezing levels will remain below 4000’ through early tomorrow morning.  Freezing level rise to or above 5000’ tomorrow afternoon.

Winds Base: 5-10 W Ridge Top:  5-15 W gusty Trend and Timing: Westerly flow will continue through the next 24hrs and then shift easterly.

6:00 Start Sun April 14th ABS

Mountain Weather Forecast

Stevens Pass Mountain Weather Forecast

Day and Time: Saturday 0630

Current Observations:

24hr Precipitation:   .12” SWE / 0" snow

Pass temperature: 34 base / 30 ridgetops

Pass level winds: Light from the west

Barometer:  Steady at 1011

Sky: Overcast

Radar: Moderate rain across Puget Sound

The Forecast: Moderate snow all day Saturday, with cooling temps and gusty winds in the afternoon. Light snow continuing Sunday, ending Sunday afternoon at lower snow levels. 

  

The Science: Another triple point system, similar to Wednesday/Thursday's storm, is arriving in NW flow today. Temperatures will bump up a few degrees midday with the warm front and daytime warming but the trailing cold front this afternoon should usher in cool air and a rapid fall in temperature. Post frontal westerly flow will drive orographic snowfall throughout the evening, with a convergence zone possible setting up overnight. 

Long Range:  Another low pressure system moves through the area Monday night and Tuesday. The bulk of the moisture will be directed into Northern Oregon, but the Central Cascades will see light to moderate snow as well. High pressure is slated to set up for Wednesday and Thursday, with more active weather at the end of the week. 

Confidence: Good for the general setup today and tomorrow, exact snow amounts are always tricky with convergence zones. 

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .75  snow: 8-10" Tomorrow’s 24hr water: .25-.5    snow: 2-4" Trend and Timing: Light snow becoming moderate Saturday, possibly heavy in showers. Tapering off Sunday.

Temperature: Low: 27    High: 38 Snow/Freezing level: 4500-2500' Trend and Timing:    Temps will again be above freezing mid-day, but fall quickly late in the afternoon and overnight

Winds Base: W 10-20 Ridge Top: SW-W 15-25 with gusts  Trend and Timing: Winds will strengthen during the daylight hours, easing overnight but remaining moderate.

8:00 Start Sat April 13th ABS

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time:  0700 Friday

Current Observations:

24hr Precipitation:        .38swe, 2” of snow 

Temperature profile:     33 base, 30 ridge

Pass level winds:            light, westerly

Barometer:                    1012mb’s holding

Sky:                               OC

Radar: lights snow falling at Stevens with convergence zone activity over the I-90 corridor.

The Forecast: Light snow today with possible sun breaks this afternoon.  Temperatures will try and hit 40 this afternoon.  Another foot of snow by Sunday morning?

Long Range:  Snow showers linger into Monday with a drying, clearing and warming trend beginning on Tuesday.

  

The Science:  Tomorrow: Another late winter storm is preparing to enter the regions with a foot of snow possible by Sunday noon or so.  The leading edge of the frontal wave is expected arrive mid-morning. The trailing cold front will swing through during the afternoon with falling temperatures and westerly flow filling in.  Freezing levels will start out 4500-5000’ and then fall below 4000’ through the day.   Convergence orographics with gusty westerly winds will be likely.

Long range. A weak low pressure cell will keep showers and cloudy conditions in the discussion through Monday.  A high pressure ridge begins to build on Tuesday for a good dose of sunny spring weather for the remainder of the week.  

Forecast confidence:  Good.  There are always questions with convergence conditions but things are shaping up nicely for good snow event.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .25  snow: trace Tomorrow’s 24hr water: .75-1  snow: 8-12 Trend and Timing: Light passing mixed rain and snow showers today.  The main push of moisture arrives after 7am tomorrow morning with mixed rain and snow shifting to snow.

Temperature: Low: 30  High: 40 Freezing level: 5500’ – 4000’ Trend and Timing:    Freezing levels will peak above 5k this afternoon and then begin to fall early tomorrow morning.

Winds Base: 0-5 E shifting W Ridge Top: 0-10 NE shifting E Trend and Timing: Weak east flow at the surface today.  Gusty westerly winds can be expected with tomorrow’s storm.