8:00 Fri March 1st no ABS

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time:  Thursday 0630

Current Observations:

24hr Precipitation:  3” snow, .12swe

Temperature profile: 16 base, 14 upper mountain

Pass level winds: light and out of the west

Barometer: 1012mb’s and slowly rising

Sky: mostly clear

Radar: snow showers over the eastern basin with clear skies over the mountains.

The Forecast:  It was nice to see that a few inches of snow made it through last night.  Mostly dry with clearing can be expected today and tomorrow.   The daytime temperatures will also be bump up a few degrees.  

Long Range: The week will wrap up cool and dry with daytime temperatures in the mid to upper 20’s.   This pattern will continue through the weekend.  There will be a possibility of some snow during the middle of next week.

  

The Science: The low pressure centered over the PNW coastal waters will slowly drift south today.   The rising barometer is indicative of the weak mid-level ridge that has formed over the mountains. This feature has shifted the flow from east to northwest and stabilized the atmosphere just a bit.   Hence the clearing.

Surface lows will continue to form over the region but with little to no moisture available.  The ECMWF model swings more snow showers into the region on Wednesday with the GFS keeping things mostly dry.  Regardless, these systems are not huge producers or pattern changing events.  Therefore, we can expect the first full week of March to have cool temperatures with periodic light snow showers.

Forecast confidence:  Good.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: <.10  snow: trace Tomorrow’s 24hr water: 0  snow: 0 Trend and Timing: Mostly dry with a few light snow showers possible.

Temperature: Low: 15  High: 26 Freezing level: +-1000’ Trend and Timing:    Freezing levels lift off of sea level today with cool temperature continuing in the mountains.

Winds Base: 0-10 W Ridge Top: 5-10 NW Trend and Timing: NW flow will stick around today and then shift back to easterly late tomorrow.

8:00 Thursday Feb 28th no ABS

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time:  Wednesday 0700

Current Observations:

24hr Precipitation:  0

Temperature profile: 15base, 12ridge

Pass level winds: moderate to strong - easterly

Barometer: 1008mb’s and steady

Sky: mostly clear  

Radar: The North Central Cascades are dry with light precipitation on the fringes of the state. 

The Forecast:  Cold temperatures, gusty winds, light snow flurries and sun breaks can be expected again today.   The wind will diminish this afternoon.

Long Range: This relatively dry, but a touch warmer weather pattern will bring us into the first days of March.    

  

The Science: Moisture, rotating around a low pressure trough will continue to sit over the PNW for the next few days.  The lack of snow for Cascade mountains is due to the the axis of the low directly centered over Western Washington.  The main activity will remain on the edges; the coast, to the south and east.  

The system will slowly drift away leaving the PNW dry, cool and clear for the start of the new month. 

Forecast confidence: Good.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: <.10  snow: Trace Tomorrow’s 24hr water: >.10  snow: trace Trend and Timing: Some light flurries will be floating around today with mostly dry conditions expected.

Temperature: Low: 15  High: 20 Freezing level: Sea level – +500’. Trend and Timing:    Temperatures will remain low.

Winds Base: 5-15 E shifting WSW Ridge Top: 10-20 E shifting W Trend and Timing: The gusty easterly winds will diminish through the day and then shift SW overnight.

8:00 No ABS Wednesday the 27th

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time: Tuesday 0630

Current Observations:

24hr Precipitation: 0

Temperature profile: 15base, 11ridge

Pass level winds: light and out of the east

Barometer: 1010mb’s and falling

Sky: Partly cloudy with pass level fog

Radar: Dry throughout the State

The Forecast: Today will be cold with a few light snow flurries possible between the sun breaks.

Long Range: The weather will remain relatively dry with cold temperatures and a few light passing snow showers for the remainder of the week.

  

The Science: Most of the activity is to the south and east of Stevens Pass, rotating around a low pressure trough developing off of the Oregon Coast.  This will be the pattern as the axis of the low retrogrades north and settles over Western Washington.  Unfortunately, this is little energy to tap into and will likely only produce some mid to upper level clouds.  

Note that the ECMMF (European) differs from the GFS model on how far north the moisture reaches over the next few days.  So we will keep the possibility of some snow showers in the discussion.  Either way, there isn’t much moisture to play with so only an inch or two can be expected.    

Forecast confidence: Good to fair due to the model discrepancy.  

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: < .10 snow: trace Tomorrow’s 24hr water: .10  snow: 1-2 Trend and Timing:  A few light snow flurries will be possible today with mostly dry conditions persisting through the week.

Temperature: Low: 10   High: 22 Freezing level: Sea Level Trend and Timing:    Freezing levels will remain low.

Winds Base: 5-15 E Ridge Top: 5-20 Trend and Timing: Easterly flow will increase later today with gusty downslope winds blowing through the night.

8:00 No ABS Tuesday the 26th

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time:  Monday 0630

Current Observations:

24hr Precipitation: 1” of snow

Temperature profile: 18base, 12ridge  

Pass level winds: light

Barometer:1007mb’s and falling

Sky: OC

Radar: light snow is falling in the southern Columbia basin with the northern portion of the state being cloudy and dry.  

The Forecast:  Clearing with cold temperatures and gusty winds will move in today.    

Long Range: This stretch of cold, dry weather will finish out the month and likely bring us into March.   

  

The Science: A long stretch of snow, extending from Portland Oregon to Bismarck North Dakota will drift southeast over the next 24hrs.  This is the source of the full-on blizzard that the Midwest is bracing for.     

As the low pressure system drags south, the counter clockwise rotation will pull in a cold, dry air mass from the intermountain west.  This dry air mass will settle over the PNW for the next 5-7days with little moisture available.  Strengthening   East/offshore pressure gradients will also produce moderate to strong Pass level winds today.

Forecast confidence: Good.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: 0  snow: trace Tomorrow’s 24hr water: 0  snow:0 Trend and Timing: A few flurries will be possible today with things drying out tonight.

Temperature: Low: 10  High: 22 Freezing level:  1000’ – sea level Trend and Timing:    Freezing levels will drop to 0 today with single digits’ lows possible early tomorrow morning.

Winds Base: 5-10 E gusty Ridge Top: 10-15 E gusty Trend and Timing: Easterly flow will strengthen today and then begin to diminish this evening.

8:00am No ABS Monday the 25th

Mountain Weather Forecast

Stevens Pass Mountain Weather Forecast

Day and Time: Sunday 0715

Current Observations:

24hr Precipitation:   .25” SWE / 4” snow (6% density)

Pass temperature:  19 degrees

Pass level winds:  Light, easterly

Barometer:  Falling slowly, 1010 mbs

Sky: OVC

Radar: Light to moderate showers across the state.

The Forecast: Partly cloudy with diminishing snow showers today, temperatures remaining cool. Partly cloudy with a light snow flurry or two on Monday, at continuing low freezing levels.

  

The Science: A low pressure trough extending from interior Canada is directing cold air across the PNW. The upper level flow is moving across the Pacific and picking up some moisture, but most of that moisture is riding the strongest flow into Northern Oregon. Washington is picking up light showers from bands of moisture rotating through the trough. The east side of the Cascades should see some moderate accumulations due to the upslope orographic effect as an embedded low pressure feature moves through the trough.

Long Range:  A high pressure ridge sitting out in the Pacific leans inward a bit on Monday and Tuesday, pushing the trough a little further east and diminishing the potential for moisture. Temperatures remain cool all week, with a few inches possible during the second half.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .10  snow: trace-2” Tomorrow’s 24hr water: <.10  snow: trace Trend and Timing: Light snow ending Sunday afternoon, mostly dry Monday.

Temperature: Low: 14    High: 25 Freezing level: 500’ Trend and Timing:    Steady cool temperatures.

Winds Base: E 10-15 Ridge Top: E 10-25 Trend and Timing: East winds becoming gusty Sunday afternoon/Monday morning.

7:30 No ABS Sunday

Mountain Weather Forecast

Stevens Pass Mountain Weather Forecast

Day and Time: Saturday 1130

Delayed this morning due to avalanche control. 

Current Observations:

24hr Precipitation:   .5” SWE / 10” snow (5% density)

Pass temperature:  26 degrees F

Pass level winds: calm

Barometer:  1014

Sky:  Partly Cloudy

Radar: Precip in a convergence zone near the Skagit county line, light scattered showers elsewhere.

The Forecast: Increasing clouds and light snow developing Saturday afternoon/evening. Precip tapering off and becoming mostly dry and cloudy on Sunday.

  

The Science: A weakening low pressure system will arrive in NW flow Saturday afternoon. This will spin bands of moisture through the Cascades at continuing low snow levels. North/northwest upper level flow will bring continued light snow showers Sunday.

Long Range:  Monday and Tuesday should be mostly dry. The remainder of the week will bring cool temps, partly cloudy skies, and light amounts of snow.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .25  snow: 2-4” Tomorrow’s 24hr water: .10  snow: trace-2” Trend and Timing: Light snow developing Saturday afternoon.

Temperature: Low: 17    High: 27 Freezing level: 1000’ Trend and Timing:    Cool temps during the day and overnight.

Winds Base: variable, calm Ridge Top: E 5-15 Trend and Timing: Easterly flow developing Saturday afternoon.

6:00 start Sat Feb 23rd ABS

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time:  Friday 0700

Current Observations:

24hr Precipitation:  0 and snowing lightly

Temperature profile: 20base, 19ridge

Pass level winds: light and westerly

Barometer: 1013mb’s and beginning to fall

Sky: Increasing clouds

Radar: Light precipitation starting to enter South Sound region.   

The Forecast:  Increasing snow today, intermittent snow showers can be expected through the day tomorrow.

Long Range: Cloudy, with light diminishing snow showers will be on the menu for Sunday with the start of the new week trending dry.  Temperatures will remain on the cold side through most of next week as well.   

  

The Science: The leading edge of the approaching frontal system is currently moving into Puget Sound.  This is another triple point, so expect a rise in temperatures associated with the first warm front today.  The following cold front is timing out to pass east of the crest late this afternoon; dropping freezing levels and shifting the snow to showers through the night.  

An atmospheric wave within the upper level trough will be the driver of the moderate snowfall this afternoon.  Convergence conditions will form, but the target is very much in question.   Freezing levels will peak (+3000’) this afternoon and fall in the wake of the cold front.   

Forecast confidence: Snow fall confidence is fair due to the convergence zone target question.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .5- .75  snow: 6-10 Tomorrow’s 24hr water: .25  snow: 1-3 Trend and Timing: Light snow this morning increasing after 2pm today.  Heaviest period (depending on the convergence target) will be between 2pm and midnight.  Snow shift to showers overnight with convergence showers possible.

Temperature: Low: 19   High: 28 Freezing level:  1500’ - 3000’ -2000’ Trend and Timing:    Freezing levels will rise to 3000’ by noon or so, then fall through the night.

Winds Base: 0-10 WNW Ridge Top: 5-10 W Trend and Timing: Winds will be generally light to moderate and WNW.