MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Friday, November 29, 2019, 0930

Current Observations:

24hr Precipitation:                  0

Temperature profile:               12 base,  11 ridge

Pass level winds:                      light easterly

Barometer:                             1007mbs and falling

Sky:                                         clear

Radar:                            Dry and clear throughout the state

The Forecast: Cold and dry conditions will continue through Sunday morning.

Long Range:  We can expect a little snow Sunday afternoon with next week starting out dry and warmer.  The next chance of any significant moisture will be late next week.  

  

The Science:  The falling barometer is the indicator of the high pressure beginning to weaken.  This will take a few days to erode from the region.   A low pressure system developing off the coast of Oregon/California will produce light snow showers on Sunday for Washington.  Warmer air will be pulled into the region on Monday with daytime temperature peaking near freezing.

Weak systems will pass through the region through the week with no significant snow accumulation expected.    L

Confidence:  Good short term, poor long term.

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: 0 snow: 0 Tomorrow’s 24hr water: 0  snow: 0 Trend and Timing: No moisture expected until afternoon on Sunday.

Temperature: Low:  11  High: 20 Freezing level: 500’ Trend and Timing:    Freezing levels will remain below 1000’ through early Sunday morning.  Freezing levels begin to rise on Sunday with +3500’ freezing levels expected by Monday.

Winds Base:  0-10 E Ridge Top:  5-15 E Trend and Timing: East flow will remain intact through Sunday.

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Wednesday, November 27, 2019, 0830a

Current Observations:

24hr Precipitation:      .13 SWE, 2” of snow

Temperature profile:    21 base,

Pass level winds:            Moderate to strong easterly

Barometer:                   997mb’s and falling

Sky:                               Obscure and overcast

Radar:             Snow showers lifting north through the center of the state.

The Forecast:  The main feature of today will be the wind.  30+ mph winds will persist today.  Snow showers will continue through the night.  A clearing trend begins tomorrow with mostly dry and sunny conditions expected on Friday and Saturday.

Warning: Wind chill temperatures could be at or below 0.

Long Range: The next chance of snow will be early Sunday morning with the first week of December starting out dry.   

  

The Science:  A strong storm tracked into Oregon and then shifted north into the intermountain west last night.  Spin off snow showers dusted the east slopes with a few inches of snow.  The storm is expected to continue its trek into northern Montana and southern Alberta today.   Spin off showers will continue today with strong easterly /offshore flow.

Clearing and drying begins tomorrow as a cold, dry air mass gets pushed into the region from the NE.

A weakening low pressure system will spin more snow showers through the state on Sunday. Rising freezing levels will also accompany the weekend weather pattern.  

Confidence: good.

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: .5 snow: 3-6 Tomorrow’s 24hr water: .10  snow:  trace Trend and Timing:

Temperature: Low: 14   High:  22 Freezing level: +-500’ Trend and Timing:    Early morning temperatures will be in the mid-teens with highs in the lower 20’s.  Wind chill temperatures will be near or below 0.

Winds Base: 10-20 E gusts + 30 possible Ridge Top: 15-30 E  + 40 Trend and Timing: Strong sustained easterly winds will continue for the next 24-36hrs.

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Tuesday, November 26, 2019,  0800

Current Observations:

24hr Precipitation:         .06” SWE, trace of snow

Temperature profile:       17 base

Pass level winds:               Light, easterly

Barometer:                      1008mb’s falling slightly

Sky:                    High clouds with patchy mid-level clouds

Radar:    Spotty snow showers in the I-90 corridor with the main bulk of  moisture making landfall  along the Oregon coast.

The Forecast:  Cold and mostly dry today with an occasional light snow shower possible.  Windy tomorrow with clear periods and passing snow showers.   No significant snow accumulation expected for the rest of the week.

Long Range: The next chance of snow will be over the weekend with long range models showing some promise again next week.

  

The Science:  Bands of moisture will spin north from the low pressure system tracking into Oregon today.  The east slopes will see a few inches of snow with little of the moisture making it to the crest.  Pressure gradients will tighten along the northern boundary of the low creating strong east/offshore flow. Cold air will also be ushered in from NE interior with low teens or even single digits possible.

The next storm of interest arrives over the weekend. This system tracks up from the SW with rising freezing levels and snow likely.  Details on timing and precipitation amounts are still very much in questions, so stay tuned.  

Confidence: Good in short term, poor for long range.

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: .10 snow: 0-2 Tomorrow’s 24hr water: .25  snow: 1-3 Trend and Timing: Light passing snow showers will continue through early Thursday morning.

Temperature: Low:  10  High:  20 Freezing level: 1500’-500’ Trend and Timing:  Temperatures will remain low with freezing levels dipping below 500’ tonight.

Winds Base:   5-10 E Ridge Top: 5-15 E gust +30 possible Trend and Timing: East flow will strengthen today with strong offshore flow winds developing tonight.

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Date: Monday, November 25^th 2019

Good morning sportsfans! I'll be taking on the weather forecasts a few days a week again this season, it's nice to see a little snow on the ground this morning. 

Current Observations:

24hr Precipitation:  .79” SWE / 8” snow

Temperature profile:  29 base / 25 upper mountain

Pass level winds:  Light with moderate gusts, westerly

Barometer:     1013 mbs, falling slowly

Sky:  Light snow

Radar: Widespread showers throughout the Cascade Crest

The Forecast: Mostly cloudy with light snow and cooling temperatures today. Further cooling, intermittent clearing, and perhaps a snowflake or two Tuesday.

Long Range:  The Pacific high pressure ridge leans in over Washington for the second half of the week with a low pressure center to our south.  We should see easterly flow develop bringing cool temps, partly cloudy skies, and unfortunately not much in the way of significant snowfall.

  

The Science: NW flow aloft riding over a center of high pressure in the Pacific is bringing scattered showers to Washington State this morning. Cold air originating from British Columbia is sinking south with the development of a large-scale open trough that will deepen and move east during the day. Strong zonal flow yesterday brought short, intense bouts of snow to the Stevens Pass vicinity, we’ll take what we can get.

As the trough deepens and the off-shore ridge amplifies today, upper level flow will be strongest to the south of our forecast area. A developing low pressure system will be directed into Southern Oregon on Tuesday afternoon, leaving Washington on the cold side of the jet without any real mechanism in place for lifting (read: precipitation).

Confidence: Good, there is decent agreement between model runs for the next 3-5 days.

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: .1-.25 snow: 1-3” Tomorrow’s 24hr water: .10  snow: Trace Trend and Timing: Light intermittent snow showers ending this afternoon.

Temperature: Low: 22   High: 31 Snow level: 2500’ – 1000’ Trend and Timing:    Remaining steady during the day, falling further overnight and Tuesday.

Winds Base: W 5-10 Ridge Top: W-NW 10-20 Trend and Timing: Winds will diminish throughout the day, becoming variable early Tuesday morning. -Dan

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Sunday, November 24, 2019, 0900  

Current Observations:

24hr Precipitation:          .52 water,  3” on upper ridge

Temperature profile:      33 base, 29 ridge

Pass level winds:              moderate westerly

Barometer:                      1017mb’s and slowly rising

Sky:                                  Overcast

Radar:   Convergence showers in the Hwy 2 corridor and the I-90 corridor with dry conditions to the west.

The Forecast:   Moderate snow showers with cooling temperatures can be expected today.  Snow showers taper off tomorrow.

Long Range: A drying trend will develop for the Holiday period with little to no additional snow accumulation expected through the weekend.   

  

The Science:  The cold front that brought us this blustery weather is now heading into the intermountain west.  Cool unstable NW flow will keep orographic showers likely through the night.  A dry, cool air mass will descend from the north as the week progresses with little to no precipitation likely after Wednesday. Day time low temperatures will be in high teens with day time temperatures peaking in the mid to upper 20’s. 

Forecast confidence: Good to fair.

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: .25-.5   snow: 3-5 Tomorrow’s 24hr water: .10  snow: trace Trend and Timing: Moderate snow showers will persist today with precipitation tapering off tomorrow.

Temperature: Low: 26   High: 33 Freezing level: 4500’ – 3000’ Trend and Timing:    Freezing levels will continue to slowly fall through the day.

Winds Base: 5-10 NW Ridge Top: 5-10 NW Trend and Timing: Winds will diminish today with a NW flow pattern developing.

MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Saturday, November 23, 2019, 0830

Current Observations:

24hr Precipitation:          0

Temperature profile:       32 base, 33 ridge

Pass level winds:               light westerlies

Barometer:                        1022mb’s holding

Sky:                                  Overcast

Radar:      Heavy rain falling in the NW corner of the State with the leading cloud deck moving SE into Washington.

The Forecast:  Windy and wet tonight with rain changing over to snow showers tomorrow.   

Long Range:  Snow showers with falling temperatures will be the weather pattern through the middle of next week.  Thanksgiving day will be mostly dry with light passing snow showers possible through the holiday weekend.

Snow totals from Sunday 4am through Wednesday 4am ranges between 6 and 12” of snow.   

  

The Science:  The high pressure that has been parked over the PNW will flatten today and drift south.  This will open the door for a significant pattern change.  NW zonal flow with imbedded cold fronts will drive SE along the NW coastal waters over the next 24hrs.  The warm air aloft will take some time to erode with freezing levels hanging around 5000’ through early tomorrow. 

An atmospheric wave associated with the low pressure trough will bring heavy precipitation and high winds to Stevens Pass tonight.  The trailing cold front will then swing in with lowering freezing levels and diminishing precipitation.

The long range pattern will settle into a cool unstable NNW flow with snow showers and low temperatures expected throughout the Holiday week.       

Forecast confidence: Fair

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: .75 snow: 1-3 upper mountain, trace in base area. Tomorrow’s 24hr water:  .25+  snow: 2-4 Trend and Timing: Rain arrives around sunset tonight with heaviest period between midnight and 7am.  Intermittent snow showers expected through the day tomorrow.

Temperature: Low: 30  High: 36 Freezing level: 5000’- 4000’ Trend and Timing:    Freezing levels will slowly begin to fall tonight dropping below 4000’ early tomorrow morning.

Winds Base: 5-15 W Ridge Top: 10-20 W gusty Trend and Timing: Winds will increase tonight with 40+ ridge top gusts likely. Winds diminish and shift NNW tomorrow.

jM