8:00 Start Sunday, January 1 No ABS

Come ring in the new year with several thousand of your closest friends!

-253

Mountain Weather Forecast

Time and Day:  0830 Saturday

The Snapshot:   Light/moderate snow this afternoon and evening at low snow levels. Very cold and dry starting Sunday and lasting into next week. 

The Science:  A low pressure system will approach from the NW down the BC coast Saturday afternoon. Short lived frontal snowfall at cold temperatures will end Sunday morning after the front passes and dry, cold air fills in from the NE. The low pressure becomes stationary near the WA/OR border on Sunday, with high pressure off the coast. This should support Fraser River outflow and unusually (except this December) cold temperatures in Washington. 

The Long Range:  A stationary synoptic pattern will funnel very cold air directly from the Arctic into the Pacific Northwest. Typically, these scenarios bring cold temperatures but very little precipitation and next week should be no exception. Expect cold and dry conditions through the extended period. Regarding the upcoming holiday:

AFTER THE YEAR OF THE MONKEY COMES THE YEAR OF THE ROOSTER, WHICH BEGINS JANUARY 28, 2017. THE ROOSTER BEING THE SIGN OF DAWN AND AWAKENING, TRIUMPH AND SUCCESS CAN ONLY BE ACHIEVED AT THE PRICE OF HARD WORK AND PATIENCE IN 2017.

Precipitation Ending at 4am: Today 24hr water = .5   Snow = 4-6" Tomorrow’s 24hr water =  >.10   Snow = 0-1" Trend and Timing:  Light snow will begin Saturday afternoon and become moderate before midnight. Snow will taper and end around daybreak Sunday.

24hr temperature ending at 4 am tomorrow:  Low: 16    High: 24 Freezing level: 1000'-Surface Trend and Timing: Freezing level and temperatures will fall Saturday afternoon and evening behind the front.

24hr Winds (mph) ending at 4 am tomorrow: Base: 5-15 W Ridge Top: 10-25 W/SW, then light N Trend and Timing: Winds should shift from light westerly, to moderate with gusts from the SW as the front passes Saturday night. Early Sunday morning ridgetop winds will be light from the north.

8:00 Start Saturday, December 31, No ABS

MOUNTAIN WEATHER FORECAST

Time and Day:  1000 Friday

The Snapshot:  Partly sunny and mostly dry today with a few inches of snow possible tomorrow.   Sunday through most of next week will be dry and cold. 

The Science:  The barometer has clicked up a few notches which will start to thin the cloud cover and produce mostly dry weather for the remainder of the day.   A low-pressure system descending in from the BC interior will bring a few more inches of snow and colder temperatures to the Stevens Pass tomorrow afternoon and evening.   

The Long Range:   Sunday will mark the beginning of a prolonged dry and cold period.  A dome of high pressure currently building in the Gulf of Alaska will park itself along the PNW coast.  This will allow cold, dry arctic air to stream in the NE which will drop temperatures into the single digits or lower for the first part of the New Year.

Precipitation Ending at 4am: Today 24hr water = .10 Snow = 0-2 Tomorrow’s 24hr water =  .25 snow = 2-4 Trend and Timing: A few light snow showers may still show up today, but for the most part, the snow is complete.  Light snow begins tomorrow afternoon.

24hr temperature ending at 4 am tomorrow:  Low: 24    High: 16 Freezing level: 3000’ – 1500’ Trend and Timing:    Temperatures will slowly fall over the next 24-48hrs.  Freezing levels will reach sea-level on Sunday.

24hr Winds (mph) ending at 4 am tomorrow: Base: 0-5 W Ridge Top: 5-10 NNW  gusty Trend and Timing: Winds will shift northwest, then northeast over the next +-36hrs.

jM

6:15 Start Friday, December 30 ABS Yes

MOUNTAIN WEATHER FORECAST

Time and Day: 0700 Thursday

The Snapshot:  Mild temperatures with light snow today, moderate snow tonight, dry tomorrow, more snow on Saturday.   Cold and clear weather will bring in the new year.

The Science:  Stevens Pass received 2” of new snow overnight.  A triple point frontal system with a southwest fetch of moisture will push another round of snow into the Cascade Mountains later today.   Temperatures are expected to spike near 32⁰  in response to the warm air behind this morning’s warm front.  A good dose of moisture is expected on the backside of the warm front this afternoon/evening.

As with most triple point systems, a cold front will follow late tonight, dropping temperatures and switching the snow to showers and, eventually bringing the precipitation to and end sometime early tomorrow morning.   

The Long Range:   A low-pressure system slides down the BC coastal mountain range with more snow in tow; this should reach Stevens Saturday/Saturday night. A cold, dry air mass settles in over the PNW early next week.  Temperatures could dip into the single digits on Tuesday or Wednesday.   No significant snow is expected for most of next week.

Precipitation Ending at 4am: Today 24hr water = .75+  Snow = 6-10 Tomorrow’s 24hr water = .25 snow = 1-3 Trend and Timing: Light snow this morning with snow ramping up after 12 pm today.  Moderate to heavy snow showers ends after 7 am tomorrow morning.

24hr temperature ending at 4 am tomorrow:  Low:  22   High: 32 Freezing level: 4000’ – 2500’ Trend and Timing:    Freezing levels will have a midday peak around 4000’ and then begin to fall in the wake of the cold front early this evening.

24hr Winds (mph) ending at 4 am tomorrow: Base: 0-5 E Ridge Top: 0-10 ESE  Trend and Timing: Winds will shift from east to west with the passing of the cold front tonight. Gusty frontal winds should be expected.

jM

8:00 start thur Dec 29th ABS

MOUNTAIN WEATHER FORECAST

Time and Day: 1200 Wednesday

The Snapshot:  The sky is beginning to clear over Stevens Pass.   Light snow can be anticipated to arrive early tomorrow morning and with moderate snow tomorrow night and into Friday. 

The Science:  Clouds have begun to break up as a weak high pressure ridge slides over the mountains.   Radar is still picking up some moisture to the north, but for the most part, the snow has ended for the day.   

A weak warm front will sag south tonight pushing freezing levels up to +-4000’ tomorrow.  There is not a lot of available moisture with this first front, so expect light snow with temperatures near or just above freezing for most of tomorrow.   Cool unstable NW flow drives in the main batch of moisture tomorrow afternoon/evening with freezing levels dropping to around 2500’ early Friday morning.   

The Long Range:   Light snow can be expected on Saturday as a weak disturbance slides down the coast.  It appears that our recent storm cycle that has dumped all this glorious snow will come to and end for the start of the New Year.  Long term models have a dry, cold and stable airmass (high pressure) parking itself over the NW coastal region starting January 1^st 2017.  

Precipitation Ending at 4am: Today 24hr water = <.25 Snow = 1-2 Tomorrow’s 24hr water = .5-.75  snow = 6-8 Trend and Timing: Light snow develops early tomorrow morning with light snow showers through the day.   Heavier snow arrives after 2 pm tomorrow.

24hr temperature ending at 4 am tomorrow:  Low: 20    High:  28 Freezing level: 3000’-4000’ Trend and Timing:    Surface temps will drop under clear conditions tonight.  Freezing levels will rise to 4000’ or so tomorrow.

24hr Winds (mph) ending at 4 am tomorrow: Base:  0-5 E Ridge Top: 5-10 ESE Trend and Timing:  Light east flow develops tonight. Wind shift westerly with the passing of the front tomorrow afternoon.

jM

MOUNTAIN WEATHER FORECAST

Time and Day: 1200 Tuesday

The Snapshot:   Snow showers diminishing overnight with light snow and sun breaks tomorrow, more snow on Thursday and Friday.

The Science:  Moderate snow showers will begin to taper off later today as the Puget Sound Convergence Zone slowly weakens.  Tomorrow will be mostly dry with clear periods as a midlevel pressure ridge slide over the state. 

Thursday:  A similar storm as today will move into position Thursday with another foot of snow possible leading into Friday morning.  

The Long Range:  There will be a chance of some light snow on Saturday with cold, clear weather for the start of the New Year.

Precipitation Ending at 4am: Today 24hr water =  .75+ Snow = 8-10 Tomorrow’s 24hr water = .10  snow = 0-1 Trend and Timing: Convergence showers will continue through early tomorrow morning.  Snow ends after 7 am tomorrow morning.

24hr temperature ending at 4 am tomorrow:  Low: 20    High:  26 Freezing level: +-3000’ Trend and Timing:    Freezing levels have settled in around 3000’ today and will remainder around that elevation through tomorrow.

24hr Winds (mph) ending at 4 am tomorrow: Base:  5-10 W Ridge Top:  5-15 W, gust +20 at times along the ridge tops Trend and Timing:  Gusty westerly winds will continue into early tomorrow morning.

jM

6:15 start wed Dec 28th ABS

6:15 start tue Dec 27th ABS

MOUNTAIN WEATHER FORECAST

Time and Day: 0630 Monday

The Snapshot:  A winter storm watch begins today with heavy snow and wind expected in the mountains this evening and tomorrow.   Snow is likely to continue into Wednesday morning with another system coming into play for the end of the week.

The Science:   The leading edge of the approaching frontal system is currently just making landfall along the Olympic Peninsula.  Snow should begin to fall at Stevens this afternoon and intensify through the night.  A warm airmass ahead of the front will temporarily bump freezing levels up to +-3500’ late tonight.   Strong cool westerly flow with PS convergence zone effects will greet the day tomorrow with heavy orographic snow likely for most of the day.   

The Long Range:  More snow arrives on Thursday and then a weaker system again on Saturday.  Long term models indicate cold and dry heading into the New Year.

Precipitation Ending at 4am: Today 24hr water = .75-1 Snow = 8-12 Tomorrow’s 24hr water = 1 snow = 8-14 Trend and Timing: Snow begins after 2 pm today and ramps up through the night.  Convergence showers persist through most of tomorrow.

24hr temperature ending at 4 am tomorrow:  Low:  22   High: 26 Freezing level: 3500’ – 2500’ Trend and Timing:    Temperatures will peak (+-260 ) around midnight tonight.  Freezing levels will then fall to around 2500’ tomorrow.

24hr Winds (mph) ending at 4 am tomorrow: Base:  5-10 W Ridge Top: 10-2- W Trend and Timing: A short period of easterly flow will occur today.  Winds shift westerly tonight and strengthen through the early morning hours.

jM

8:00 Start Monday December 26, No ABS

Mountain Weather Forecast

Time and Day: 0800 Sunday

The Snapshot:  Clear and cold today, moderate snow beginning Monday afternoon turning heavy by Tuesday morning with a warming trend.

The Science:  Clear and cold over Washington this morning with temperatures at Stevens Pass in the mid-teens. Surface high pressure and dry northerly flow aloft will maintain sunny and cold conditions in the Cascades today. Things will begin to get interesting again Monday afternoon. A strong westerly jet stream will become centered over Washington State and carry an embedded trough across the forecast area Monday night and Tuesday morning. There will be a brief warming trend with freezing levels rising to 3000-3500 feet early Tuesday morning. East flow may help keep local freezing levels at Stevens Pass a bit lower.

Orographic snow showers will continue in strong zonal flow Tuesday and Wednesday morning. Brief high pressure will move across the area Wednesday afternoon providing a short break.

The Long Range: Behind Wednesday’s short-lived high pressure ridge, continued westerly flow and a low pressure trough will swing through Washington on Thursday/Friday for another snow event.

Precipitation Ending at 4am: Today 24hr water = 0 Snow = 0 Tomorrow’s 24hr water =  1.0  Snow = 10-12 Trend and Timing: Snow will begin Monday afternoon and quickly become heavy overnight, continuing Tuesday.

24hr temperature ending at 4 am tomorrow:                                        Low:  15   High: 22 Freezing level: 500’ Trend and Timing:    Temperatures will remain cool with low freezing levels through 4am Monday morning, then begin to rise.

24hr Winds (mph) ending at 4 am tomorrow: Base: 0-5 Variable Ridge Top: 5-10 SSW Trend and Timing:  Light east winds at Pass level through Monday morning, ridgetop winds shifting from northerly to SSW overnight. DV

8:00 Start Sunday December 25th, NO ABS

Your present will be late, it's coming Monday. Happy Kwanza and stuff.

-253

Mountain Weather Forecast

Time and Day: 0900 Saturday

The Snapshot: Light snow ending Saturday morning, sunny and cold for Christmas Day.

The Science:  A couple inches of low density snow fell overnight and temperatures are in the low 20’s this morning. Washington state is under the axis of an upper level trough which will drift east today. Light convergence showers are squeezing a few snowflakes out of the sky this morning. Dry northerly upper level flow and surface high pressure will fill in behind the trough, making for clearing skies Saturday and a sunny day Sunday.

The Long Range: Strong westerly flow will take aim at Washington State starting Monday afternoon. An embedded trough should deepen and cross the forecast area Monday night and Tuesday. Freezing levels look to rise briefly Tuesday morning, but should remain below Pass level. It’s too early for an accurate prediction, but Monday night through Wednesday Stevens Pass should accumulate 24”+ of snow. Currently Thursday looks like a break between systems, with another snow event on the horizon for Friday.

Precipitation Ending at 4am: Today 24hr water = LT .10   Snow = 1-2” Tomorrow’s 24hr water = 0   Snow = 0 Trend and Timing: The last few snowflakes for Saturday should be falling currently, no precipitation is indicated from mid-morning Saturday through Monday morning.

24hr temperature ending at 4 am tomorrow:                                        Low:  17   High: 22 Freezing level: 0-500’ Trend and Timing:    Temps and freezing level will remain cool and low through Sunday night.

24hr Winds (mph) ending at 4 am tomorrow: Base: W 0-5 Ridge Top: WNW 5-15 Trend and Timing:  Light winds through Sunday morning, turning northerly at ridgetops. DV

8:00 Start Saturday December 24 No ABS

MOUNTAIN WEATHER FORECAST

Time and Day: 0630 Friday

The Snapshot: 21degrees with 3” of new snow this morning.  Snow continues today with the Holiday weekend trending dry and clear.  Another winter storm is in the works for Monday night and Tuesday.

The Science:  A low-pressure system that has formed off the Washington coast will track NE through the state today.  This will provide steady snow and cool temperatures for the next +-24hrs.   The snow ends early tomorrow morning as the flow splits around a high pressure ridge.  The weekend will be mostly dry with clear periods and cold air settling into the eastern basin.

The Long Range:  A strong warm front will bring another round of moderate to heavy snow and a spike in freezing levels Monday night.  Cool unstable flow fills in on Tuesday with snow likely falling into early Wednesday morning. 

Precipitation Ending at 4am: Today 24hr water = .25 - .5 Snow = 3-6 Tomorrow’s 24hr water = .10 snow = 0-1 Trend and Timing: Snow will be light today but consistent.  The precipitation tapers off early tomorrow morning with most of tomorrow and Sunday being dry.

24hr temperature ending at 4 am tomorrow:                                        Low: 14    High: 22 Freezing level: 3000’ – 2000’ Trend and Timing:    Temperatures will decline today and remain in the upper teens through the weekend. Sunshine may push daytime temps into the lower 20’s tomorrow and Sunday.

24hr Winds (mph) ending at 4 am tomorrow: Base: 0-10 E Ridge Top: 5-10 E Trend and Timing: Winds have shifted east and will strengthen today. Winds shift to westerly tonight with light westerly flow persisting through the weekend.

jM

8:00 Start Friday December 23, No ABS

MOUNTAIN WEATHER FORECAST

Time and Day: 0630 Thursday

The Snapshot: Light snow today,  snow continuing tomorrow with the weekend trending dry.  

The Science:  Clouds are beginning roll in with lights snow starting to show up on radar.   Temperatures are inverted with the upper mountain be 8-10⁰ warmer.  This is due to the warmer air mass creeping up the western slopes of the mountains.  

Warm southwest flow ahead of an approaching cold front will bring snow to Stevens Pass today.  There may be a rain drop or two in the mix for a short period this afternoon as temperature advection occurs along the western slopes. Once the front moves through later this afternoon, temperatures will begin to fall; the snow will also turn to showers.  

A low-pressure trough will form tomorrow which is currently expected to head into the southeast portion of the state and then stall over Eastern Washington.  The bulk of the moisture will be concentrated along the south and eastern slopes of the Cascades.  Stevens will get a bit of the moisture but not the main hit.   Cold air will also be pulled in from the north, lowering freezing levels heading into the weekend.  

The Long Range:  The moisture clears out Saturday as a split flow pattern emerges.  Cool NW flow will bring snow back to the conversation during the final week of the year.  

Precipitation Ending at 4am: Today 24hr water = .25 Snow = 2-4 Tomorrow’s 24hr water = .25  snow = 2-4 Trend and Timing: Very light snow showers this morning shifting to snow late this afternoon.  Lights snow will persist into Saturday morning.

24hr temperature ending at 4 am tomorrow:  Low: 22    High: 30 Freezing level: 4500’ – 3000’ Trend and Timing:    Temperatures will climb to near freezing today but with an overall cooling trend starting tonight.

24hr Winds (mph) ending at 4 am tomorrow: Base: 0-5 E shifting W Ridge Top:  0-10 SW Trend and Timing: Weak east flow at the surface with SW flow aloft will slowly shift westerly over the next 24hrs.  Winds will shift east to west and back again with the passing of these next few systems.

jM

8:00 start Thur Dec 22nd no abs

MOUNTAIN WEATHER FORECAST

Time and Day:  0600 Wednesday

The Snapshot: A “quiet” weather day today with some sunshine.  Light snow showers develop tomorrow and persist into the weekend.

The Science:   6” of snow fell yesterday with mostly clear skies and light winds this morning.  Temperatures cooled off nicely due to the clearing.  22⁰ .

 A high-pressure system developing over the Oregon/Idaho region will provide dry and partially clear weather for Stevens Pass today. Temperatures will also be on warm side with SW flow entering the region.

Clouds will increase tonight in response to a weak disturbance tracking in from the NW.  Light snow will show up tomorrow with intermittent showers persisting through the rest of the week.   

The Long Range:  A low-pressure system forming off the coast of California will track northeast through Oregon and eventually Eastern Washington over the weekend.  This will likely spin light bands of snow along the eastern slopes of the Cascades.  Cold air from the north will also return for low temperatures heading into the holiday weekend.  

Precipitation Ending at 4am: Today 24hr water =  .10 Snow = trace Tomorrow’s 24hr water = .25 snow = 2-4 Trend and Timing: Dry today with light snow developing during daylight hours tomorrow.

24hr temperature ending at 4 am tomorrow:  Low:  22   High: 36 Freezing level: 3000’ -4500’ Trend and Timing:    Freezing levels spike up today then slowly fall through the rest of the week.

24hr Winds (mph) ending at 4 am tomorrow: Base: 0-5 E Ridge Top: 0-10  SE Trend and Timing:  Light east flow at the surface with southerly flow aloft will develop today.

jM