8:00 Start Saturday April 1, No ABS

Mountain Weather Forecast

Time and Day: 0745 Friday

The Snapshot: A sunny and warm day in store for Friday, increasing clouds and light rain/snow Saturday.

The Science: A high pressure ridge is positioned over the Washington coast this morning. This feature should give the PNW a nice dose of sunny spring weather for most of Friday. High clouds in advance of the next warm front will start to move in Friday night. Light rain will start Saturday morning, tapering down midday after the warm front passes. When the trailing cold front moves across the crest Saturday night there will be a period of renewed light showers, hopefully in the form of snow. Sunday will bring temperatures near seasonal norms, possible light snow showers, and partly cloudy skies.

The Long Range: After a low pressure trough moves through on Sunday, high pressure rebuilds Monday and Tuesday with partly cloudy skies likely and freezing levels bouncing between 3000-5000’.

24hr Precipitation ending at 4am: Today 24hr water = 0 snow = 0 Tomorrow’s 24hr water = .25-.5  snow = 2-4” Trend and Timing: Dry all day Friday, light precip starting as rain Saturday morning, then turning to light snow by Sunday morning.

24hr temperature ending at 4am:  Low: 25   High: 40 Freezing level: 3,000’-6500’ Trend and Timing:    Temperatures rapidly increasing Friday midday, gradual cooling overnight.

24hr Winds (mph) ending at 4am: Base: Variable 0-5 Ridge Top: W 5-10, then WSW 15-20 Trend and Timing: Light winds most of Friday, increasing overnight as the next front approaches.

8:00 start Friday March 31, No ABS

Mountain Weather Forecast

Time and Day: 0720 Thursday

The Snapshot:   Light snow showers ending today, sunny and clear Friday.

The Science: The last spurts of post frontal snow showers are happening this morning as high pressure begins to build over the Pacific. 5” between midnight and 5am will help with the ski quality this morning. Westerly flow will squeeze out whatever moisture comes off the Pacific today in light snow showers with precipitation tapering and ending Thursday afternoon. Clearing skies can be expected by Thursday night. Friday should be a beautiful spring day

The Long Range: Westerly flow begins again Saturday with a weak trough impacting the region. The snow/rain line currently looks to be somewhere around 4500-5000’, with moderate amounts of precipitation. Sunday and Monday look partly cloudy with light passing snow showers.

24hr Precipitation ending at 4am: Today 24hr water = .25-.5   snow = 2-4” Tomorrow’s 24hr water = 0  snow = 0 Trend and Timing: Light snow showers ending Thursday afternoon. Dry on Friday.

24hr temperature ending at 4am:  Low:  25   High: 34 Freezing level: 3500-4500 Trend and Timing:    Relatively cool temperatures during the day Thursday until the sun comes out. Warming quickly Friday morning.

24hr Winds (mph) ending at 4am: Base: W 5-10 Ridge Top: W20-30, then 5-10 WNW Trend and Timing: Gusty west winds Thursday morning should taper down and become calm by Thursday evening.

8:00 Thurs March 30th no ABS

Mountain Weather Forecast

Time and Day: 1030 Wednesday

The Snapshot: Rain today, switching to moderate snow overnight and Thursday. Snow ending Thursday afternoon and high pressure building for Friday.

The Science: Snow overnight transitioned to rain this morning by the end of control work. As the warm front approaches Wednesday, east flow will give out and freezing levels will rise midday. A warm mass of upper level air will move over Washington bringing continuing rain during the day. The trailing cold front should cross the Cascades around the end of daylight hours Wednesday. Precipitation will transition back to snow overnight, with some periods of moderate snow through Thursday midday. Snow will taper and end Thursday afternoon.

The Long Range: Building high pressure Thursday night will move over the West Coast Friday bringing a sunny and warm day. Another trough affects the region Saturday and Sunday with the rain/snow game continuing.

Precipitation Ending at 4am: Today 24hr water = .75-1.0 Snow = 3-5” Tomorrow’s 24hr water = .25-.5 Snow = 2-4” Trend and Timing: Rain should occur during the rest of the daylight hours on Wednesday with a switch back to snow just after dark. Light to moderate snow thru Thursday afternoon then tapering off and ending by Thursday night.

24hr temperature ending at 4 am tomorrow:                                        Low:  28   High: 35 Freezing level: 6000-3000’ Trend and Timing:    Snow level should raise to 6k Wednesday afternoon, then fall overnight back below Pass level.

24hr Winds (mph) ending at 4 am tomorrow: Base: E 0-5, then W 5-10 Ridge Top: E 5-10 then WSW 10-20 Trend and Timing: East winds should switch to WSW midday Wednesday and strengthen a bit as the cold front approaches. DV

6:15 Wed March 29th ABS

Mountain Weather Forecast

​Note: John Meriwether is out of the country for a bit, so I will issue forecasts as they are pertinent on my days off. I'll send out an update on Tuesday/Wednesday's storm tomorrow evening. 

Time and Day: Monday and Tuesday

 

The Snapshot: Dry Sunday morning with moderate snow moving in Sunday afternoon.

 

The Science: 5" seems to be the new daily norm. After yesterday's frontal passage Washington is in a relatively cool trough with moderate upper level westerly flow bringing continued light snow showers. As the trough moves east today, westerly flow will continue to bring moist air into the region and support snow showers throughout the day Monday and into the evening. A tapering of precip is indicated for Monday night/Tuesday morning. 

The next feature to impact our region is easily visible on satellite:(http://www.atmos.washington.edu/cgi-bin/latest.cgi?fronts-ir)

A triple point low will begin to affect Western Washington Tuesday afternoon. Currently the precip type looks to be snow on Tuesday and Wednesday morning. There is plenty of moisture with this system and light east flow indicated for Stevens Pass on Wednesday morning. The free air freezing levels are in our favor for all of Tuesday and early Wednesday, so Stevens could pick up significant snow accumulation by daylight Wednesday morning. The rub is that there simply isn't much cold air east of the Cascade Crest this time of year. This event could play out a number of ways so confidence is low in the final outcome by Wednesday morning but the best guess is heavy snow Tuesday night and early Wednesday, with a switch to rain around daylight Wednesday morning. Moderate rain continues during the day Wednesday before the trailing cold front arrives and drops snow levels again. 

 

The Long Range: After a switch back to snow Wednesday night/Thursday morning, Stevens should see light snow accumulations Thursday. High pressure builds into the PNW on Friday, bringing a sunny and warm day. Another low pressure trough moves into the region over the weekend for light snow/rain. 

 

 

24hr Precipitation ending at 4am: Today 24hr water = .25-.5  snow = 2-4" Tomorrow’s 24hr water = 1.0  snow = 8-12+"   Trend and Timing: Light snow showers will continue Monday, with a decrease overnight and Tuesday morning. Moderate snow begins again Tuesday midday, becoming heavy overnight and early Wednesday morning. A switch to rain is indicated mid-morning Wednesday.

24hr temperature ending at 4am:  Low: 28    High: 35 Freezing level: 4,000'- 6,000'   Trend and Timing:    Snow levels should remain at or just above Pass level through Tuesday night before spiking to 6,000' or so Wednesday morning.

24hr Winds (mph) ending at 4am: Base: W 5-15 Ridge Top: WSW 10-20, then 20-30 Tuesday night   Trend and Timing: Light to moderate westerly winds Monday and Tuesday, becoming stronger Tuesday afternoon and evening. Easterly Pass level flow is indicated Tuesday night and Wednesday morning as the warm front approaches.

8:00 Tue March 28th no ABS

8:00 Start Monday March 27, NO ABS

Mountain Weather Forecast

Time and Day: 9:30 Sunday

The Snapshot: Dry Sunday morning with moderate snow moving in Sunday afternoon.

The Science: Sunday will start out dry as a short-lived high pressure ridge moves over Washington. There are currently high clouds in advance of an approaching front. The warm front should reach Stevens Pass Sunday afternoon, with the trailing cold front and cooler airmass moving in overnight. Light snow should begin Sunday afternoon and continue into Monday.

There will be a brief break from precipitation Monday before westerly flow increases and brings moisture and more light snow to the Cascades Monday afternoon and Tuesday.

The Long Range: A warm and wet system looks to arrive Tuesday night and Wednesday. Freezing levels look to be around 5000-6000’ with a decent shot of moisture. There is cooling and hopefully a return to snow on Thursday, with high pressure building by the end of the week.

24hr Precipitation ending at 4am: Today 24hr water = .5  snow = 3-5” Tomorrow’s 24hr water = .25-.5  snow = 2-4” Trend and Timing: Light to moderate snow beginning Sunday afternoon, a brief break Monday morning, moderate snow showers resuming Monday afternoon.

24hr temperature ending at 4am:  Low: 25    High: 33 Freezing level: 3500-4000’ Trend and Timing:    Temperatures will bump up with daytime warming as has been the pattern. Snow levels should remain at Pass level.

24hr Winds (mph) ending at 4am: Base: E 0-5 then W 5-10 Ridge Top: E 5-10 then WSW 10-15 Trend and Timing: East winds during the day Sunday will switch to WSW as the front crosses Sunday afternoon.

8:00 Start Sunday March 26, No ABS

Mountain Weather Forecast

Time and Day: 0700 Saturday

The Snapshot: Partly cloudy and cooler with light snow today, dry and partly cloudy most of Sunday.

The Science: Friday’s cold front has passed, dropping 5” of snow. Westerly flow behind the front will maintain light snow showers Saturday before a brief high pressure ridge brings dryer and slightly warmer air to the PNW overnight Saturday and Sunday. The next front will approach Sunday afternoon. It looks to be quite stretched out and thus will not pack much of a punch, but should bring another round of moderate snow for Stevens Pass. March continues.

The Long Range: Active weather continues into next week with the pattern of trough/short-lived high pressure continuing. Freezing levels bounce around between 3,000-5,000 feet so stay tuned for rain vs. snow amounts.

24hr Precipitation ending at 4am: Today 24hr water = .25   snow = 1-3” Tomorrow’s 24hr water = .25-.5    snow = 2-4” Trend and Timing: Light snow flurries during the day Saturday, ending Saturday evening. Dry Sunday morning, light snow beginning Sunday afternoon.

24hr temperature ending at 4am:  Low: 25    High: 33 Freezing level: 3500-2500 Trend and Timing:    Typical midday warming will bump the air temperature up to near or just above 32. Freezing levels should remain well below pass level Saturday night and Sunday morning.

24hr Winds (mph) ending at 4am: Base: W 5-10 Ridge Top: WSW 10-20 Trend and Timing: Consistent light winds will taper off Saturday night.

8:00 Start Saturday March 25, No ABS

MOUNTAIN WEATHER FORECAST

Time and Day: 0700 Friday

The Snapshot:   It’s 32^0f  and snowing this morning with 3” of new snow.   Mixed rain and snow is expected today with a short dose of moderate snow tonight.  Passing snow showers with sun breaks can be anticipated for the weekend.    

The Science:  A nice batch of moisture ahead of the approaching cold/occluded front is currently in the mountains.  A bit of rain below 4500’ will be added to the mix once the day begins to warms up. Radar has the back boundary of the moisture just east of the Olympics with the front still offshore.   

The front is timing out to pass east of the Cascade Crest early tonight with good westerly flow and lowering freezing levels filling in.  Hopefully, we will get a few inches of new snow to report on tomorrow morning.  A weak high pressure ridge between systems will produce clear periods but also keep the chance of snow showers possible into early Sunday morning.

The Long Range:   The weather for the first full week of spring will continue to be active with the snow/rain game continuing throughout.  There are signs of a pattern change late next week with high pressure developing off of the Oregon/California coast – this could be the start of a prolonged drying trend for the PNW, or not.   

24hr Precipitation ending at 4am: Today 24hr water = .5-.75 snow = 3-5 Tomorrow’s 24hr water = .25-.5 snow = 2-5 Trend and Timing: Snow this morning shifting to mixed rain and snow through the day.  The precipitation diminishes to light showers tomorrow.

24hr temperature ending at 4 am:  Low:  28   High: 38 Freezing level: 4500’ – 3500’ Trend and Timing:    Freezing levels will peak near 4500’ this afternoon and then begin to fall tonight.

24hr Winds (mph) ending at 4 am: Base: 0-5 ESE Ridge Top: 5-10 SE Trend and Timing: Light easterly winds shift southerly then westerly over the next 24hrs.

jM

8:00 Start Friday March 24, No ABS

MOUNTAIN WEATHER FORECAST

Time and Day: 0700 Thursday

The Snapshot:   Partly cloudy this morning with a brand new inch of snow to play on.   Today will be mostly dry with some sun breaks, more moisture is on the way.

The Science:   A weak ridge of high pressure has produced a rather peaceful morning in the mountains.  The next weather feature to pull our attention is a triple point frontal system making its way in. The leading edge of the warm front is still off the Oregon coast and is expected to reach the Central Cascades tonight.  This system is not packing a ton of energy and is expected to weaken when it hits the mountains.

You know the drill, warm southerly flow with mixed rain and snow, followed by a cold front, lowering freezing levels and then taper off the snow.  Being it is spring, early morning temperatures will be near freezing with good daytime warming - snow levels bounce between 3500’ and 5000’.

The Long Range:   Snow showers persist into Saturday with more of the same weather starting on Sunday.  The fronts keep right on coming through most of next week.

24hr Precipitation ending at 4am: Today 24hr water = .25  snow = 1-2 Tomorrow’s 24hr water = .5  snow = 2-4 Trend and Timing: Light mixed rain and snow develops tonight and continues into Saturday morning.

24hr temperature ending at 4 am:  Low: 26    High: 36 Freezing level: +-4500’ Trend and Timing:    Freezing levels will hover around 4500’ with typical daytime warming.  It is spring after all.

24hr Winds (mph) ending at 4 am: Base:  5-10 S Ridge Top: 5-15 S Trend and Timing: The strong westerly winds that blew last night will diminish and shift southerly today.

jM

8:00 start Thur March 23rd no ABS

MOUNTAIN WEATHER FORECAST

Time and Day:  0630 Wednesday

The Snapshot:  Snow showers today, dry tomorrow, more mixed rain and snow heading into the weekend.

The Science:  Showers out ahead of an approaching cold front will move through the mountains today.  Cooler westerly flow will fill in behind the front, lowering freezing levels and providing some moderate snow showers through the night.  A weak high pressure ridge will break up the moisture tomorrow for some drying and clearing. Another frontal system arrives on Friday for more of the same rain vs snow. 

The Long Range:  It seems like we are locked into this pattern of a frontal system followed by a ridge of high pressure every other day or so.  Therefore expect this active weather with freezing levels bouncing above and below 4500’ to continue through the weekend and likely into early next week.    

24hr Precipitation ending at 4am: Today 24hr water = .5 snow = 3-5 Tomorrow’s 24hr water = .25  snow = 1-2 Trend and Timing: Passing snow showers will continue today with precipitation tapering off tomorrow.

24hr temperature ending at 4 am:  Low:  26   High: 34 Freezing level: 4500’ – 3000’ – 4500’ Trend and Timing:    Freezing levels will fall tonight with daytime warming rebounding temperatures.

24hr Winds (mph) ending at 4am: Base: 0-5 E shifting W Ridge Top: 5-10 W gusty Trend and Timing: East flow this morning will shift westerly this afternoon.

jM

8:00 Wed March 22nd no ABS

MOUNTAIN WEATHER FORECAST

Time and Day: 0730 Tuesday

The Snapshot:    Gray, drizzly with mild temperatures today.  The moisture shifts to light snow tomorrow with Thursday trending dry.

The Science:  This morning’s radar has mixed rain and snow showers moving through the mountains.  The low-pressure system responsible for the dreary weather will slowly track up the coast over the next few days.   A weak cold front will swing through tomorrow lowering freezing levels a bit and changing the light rain to light snow showers.   

The Long Range:   Thursday will be mostly dry with some clear periods under a ridge of high pressure.   Another system with mixed rain and snow and seasonally average temperatures occur on Friday and Saturday. 

24hr Precipitation ending at 4am: Today 24hr water = .25 snow = trace Tomorrow’s 24hr water = .25-.5  snow = 1-3 Trend and Timing: Light mixed rain and snow continue through tomorrow.

24hr temperature ending at 4 am:  Low: 30    High: 40 Freezing level: 4500’ -  6000’ Trend and Timing:    Weak east flow will help hold temperature low this morning.  Freezing levels then peak near 6000’ later today and then fall after midnight tonight.

24hr Winds (mph) ending at 4am: Base: 0-5 E Ridge Top: 5-10 ESE Trend and Timing: East flow at the surface with SE flow aloft will be the general wind pattern through tomorrow morning.

jM

8;00 Tue March 21st no ABS

MOUNTAIN WEATHER FORECAST

Time and Day:  0730 Monday

The Snapshot:   Dry, warm and a bit breezy today with light rain developing tonight.   Tuesday will be rainy with cooler air arriving on Wednesday. 

The Science:  The high pressure that brought us the beautiful weather yesterday is being pushed east by an approaching low pressure system.   East west pressure gradients will tighten along the crest, hence the gusty easterly winds starting to blow.  Clouds will move in today, along with a warmer moist air mass. Cooler air aloft begins to fill in on Wednesday for some lower freezing levels and a bit of snow to add to the mix.        

The Long Range:   Thursday will be mostly dry with more active weather (the rain vs snow game) returning on Friday.

24hr Precipitation ending at 4am: Today 24hr water = .10 snow = 0 Tomorrow’s 24hr water = .5+ snow = 0 Trend and Timing: Very light rain shows up early tomorrow morning with light rain expected through the day.

24hr temperature ending at 4am:  Low:  24   High: 40 Freezing level: 3000’- 6000’ Trend and Timing:    Freezing levels are on the rise.  Surface temps could peak near 40 today and struggle to drop below freezing until Wednesday.

24hr Winds (mph) ending at 4am: Base: 5-10 E Ridge Top: 5-15 E Trend and Timing: Watch for gusty easterly winds along the ridge tops and down the western slopes.

jM