MOUNTAIN WEATHER FORECAST

Time and Day: 1000 Tuesday

The Snapshot:  Clouds will begin to move in today in response to the changing weather pattern.  Snow with cooler temperatures arrives tomorrow with snow showers persisting through Friday.     

The Science:   

Its 37⁰f, with an RH of 52%, the barometer is at 1016mb and starting to fall, there are some gusty westerly winds blowing along the ridge tops this morning.

A low-pressure cell that has formed along the BC coastal range is expected to track south during the next few days.  This will push the high pressure that has been stationed over the PNW out to sea and allow cooler, unstable and moist air to move in.  A weak cold front is expected to move through mid-day tomorrow which will drop the temperature a few degrees and increase the shower activity.  

Storm totals by Saturday morning will be around +-8” of fairly dry and light snow.    

The Long Range: Snow showers stick around through Friday with weekend trending dry and cold.

24hr Precipitation ending at 4 am: Today 24hr water: .10 snow: trace Tomorrow’s 24hr water: .25  snow: 1-2 Trend and Timing: Light mixed rain and snow begin early tomorrow morning with light showers persisting into Thursday.

24hr temperature ending at 4 am:  Low: 32    High: 44 Freezing level: 7000’  4500’ Trend and Timing:    Freezing levels will begin to drop early tomorrow morning with Pass level temperatures dropping below freezing by noon or so tomorrow.

24hr Winds (mph) ending at 4 am: Base: 5-10 NW Ridge Top: 10-20 WNW gusty Trend and Timing: Ridgetop winds will be strong and gusty tonight and begin to taper off tomorrow afternoon.

jM

MOUNTAIN WEATHER FORECAST

Time and Day: 0930 Monday

The Snapshot:  Dry today and tomorrow with increasing clouds.  Light mixed rain and snow on Wednesday, snow and colder temperatures finish out the week.  

The Science:   

Temp = 39f, Rh = 47%, barometer = 1021mb and steady, winds = gusty 10-15 E.

Nice daytime temperature recovery will continue today and tomorrow with a cooling trend beginning on Wednesday. The pressure/temperature gradients along the Cascade Crest that are producing these gusty easterly winds will begin to ease today with NW flow filling in tomorrow.  

The high pressure that produced this amazing weather as of late will begin to weaken and drift offshore over the next few days.  This will open the door for a pattern change to develop.  Cool unstable air sinking in from the north will allow a few weather systems to drop in from the north as the week progresses.   There will be snow associated with this new weather pattern, but because it is coming from the north interior, (cold with low Rh’s) it won’t likely pack a ton of moisture.  

As for snow, it is a bit early to have much confidence in the models; but as of now, there will be a few inches Wednesday night into Thursday with an additional 4-8” on Thursday and Friday.  Those values will likely change as the models begin to come into agreement.

The Long Range:  The weekend is trending dry, clear and cold. Low temperatures could be in the teens through the weekend.

24hr Precipitation ending at 4am: Today 24hr water:  0 snow: 0 Tomorrow’s 24hr water:  0 snow: 0 Trend and Timing: Dry through Wednesday.

24hr temperature ending at 4 am:  Low:32     High: 45 Freezing level: 4500- 7000’ Trend and Timing:    Freezing levels will fluctuate between 7000’ and 4500’ with good daytime temperature recovery.

24hr Winds (mph) ending at 4 am: Base: 5-10 E Ridge Top: 5-15 E shifting NW Trend and Timing: These easterly winds will diminish today and begin to shift north-west tomorrow.

jM

MOUNTAIN WEATHER FORECAST

Time and Day: 1200 Friday

The Snapshot:  This clear, beautiful weather will continue through the middle of next week.  Cooler temperatures will begin to filter in on Sunday.  

 

The Long Range:  There will be a chance of snow late next week.     

The Science:

Temperature = 40f,  Rh = 75%, barometer = 1024mb and holding steady.

High pressure over the PNW will continue to dominate the weather pattern through the weekend.  Things begin to slowly change early next week as the cooler unstable air begins to make its way in from the north.  

Pressure gradients will begin to tighten along Cascade Crest on Sunday as the temperature east of the mountains fall.  This will likely produce some gusty easterly winds on Monday.      

Colder temperatures and a chance of snow are beginning to show up on the long-range models. Stay tuned as those detail mature.

 

24hr Precipitation ending at 4am: Today 24hr water: 0 snow:0 Tomorrow’s 24hr water:  0 snow: 0 Trend and Timing: Dry conditions prevail through the weekend.

24hr temperature ending at 4am:  Low: 36    High: 50 Freezing level: 8-10,000’ Trend and Timing:    Freezing levels will remain high through Sunday.

24hr Winds (mph) ending at 4 am: Base: 0-10 ESE Ridge Top: 5-10 E Trend and Timing: East flow will strengthen over the few days.

jM

MOUNTAIN WEATHER FORECAST

Time and Day: 1100 Tuesday

The Snapshot:  Sunshine today with a chance of some light rain tomorrow afternoon.       

The Long Range:  The sunshine returns on Thursday with beautiful dry and clear weather continuing through the weekend.  Next chance of moisture appears to be early next week.     

The Science:  

Current conditions:  Temperature = 39, RH= 88%,  pressure = 1032mb steady.

High pressure over the PNW has settled in for the long term.  A weak cold front will move sneak in tomorrow afternoon for a short period of light rain. The high pressure will quickly re-bound for more warm, dry, clear fall weather stretching out through the weekend.  

There is an early sign of the high pressure breaking down early next week with a possible shift in the pattern.  Stay tuned.

24hr Precipitation ending at 4am: Today 24hr water:0  snow:0 Tomorrow’s 24hr water: lt .25   snow: 0 Trend and Timing: Dry today with a few hours of light rain moving in tomorrow afternoon.

24hr temperature ending at 4 am:  Low: 34    High: 50 Freezing level: 7000’ – 5500’ Trend and Timing:    Freezing levels will drop in the wake of the cold front tomorrow morning.

24hr Winds (mph) ending at 4am: Base: 0-15 W Ridge Top: 5-15 W gusty Trend and Timing: A short period of gusty westerly winds will accompany the front tomorrow morning.  Winds diminish through the day and shift easterly.

jM

MOUNTAIN WEATHER FORECAST

Time and Day: 0900 Monday

The Snapshot:  A prolonged dry weather pattern with clearing and warming begins today. It appears that we have some amazing fall weather in the works.  

 

The Long Range:  A weak system moves in on Wednesday for a chance of some light mixed rain and snow.  The sun returns on Thursday with dry and seasonably warm weather continuing through the weekend.    

The Science:  

Current conditions = Temperatures is 36f, the pressure is 1031mb and rising, and the Rh is 87%. 

A large high pressure system is building over the PNW which will produce a period of dry, clear and warm weather.  A weak cold front, sliding in from the NW, will try to bust through on Wednesday. This system will produce some clouds and some light precipitation but it is not expected to have much of a punch. 

The high pressure rebounds on Thursday and is expected to remain stationary over the PNW through the weekend and possibly beyond.

 

24hr Precipitation ending at 4am: Today 24hr water: 0  snow: 0 Tomorrow’s 24hr water: 0  snow:  0 Trend and Timing: Mostly dry today and tomorrow.

24hr temperature ending at 4am:  Low: 37    High: 48 Freezing level: 5000’ – 8000’ Trend and Timing:    Day time high temperatures could top 50f with the aid of the sun this afternoon and again tomorrow.

24hr Winds (mph) ending at 4am: Base: 0-5 W shifting E Ridge Top: 0-10 W shifting E Trend and Timing: Light easterly flow will develop over the next 24hrs.

jM

Sunday Weather Brief

Whew, what a storm.  4.6” of water with about a foot of snow fell around Stevens Pass over the last 24hrs.  The snowpack has since shrunk with extreme saturation.   Temperatures spiked to 42f just after midnight with heavy rain continuing through the night.  

Mixed rain and snow showers will slowly taper off today with freezing levels hovering around 4500’. Building high pressure will begin the drying trend tomorrow with clearing and warmer air entering the region.    

Enjoy.

jM  

MOUNTAIN WEATHER FORECAST

Time and Day:  0900 Saturday

The Snapshot:  Mixed rain and snow changing to heavy rain today, drying begins tomorrow.     

 

The Long Range:  With the exception of a weakening disturbance moving through on Wednesday, next week will be mostly dry and warm.  Indian Summer-esk perhaps. 

The Science:  It is 27f on the upper mountain and 32f at Pass level. .47” of mostly mixed rain and snow fell yesterday with just an inch or two of snow below 4500’.  The Barometer is holding steady around 1010mb.

Another strong frontal system, with an impressive amount of moisture (+3”) is getting ready to shift NW and enter the Cascade Mountains.  Freezing levels are sitting around 4500’ but will rise in the wake of the warm front.  Some cool air pooling along the eastern slopes could allow a few hours’ of nice snow accumulation prior to the shift to rain later today.   

 An impressive plume of moisture with water content values of over 3” is being fed into this storm from the SW.  In other words, get ready for a very wet period of rain with river flooding likely.

The barometer will begin to click up as the high pressure to the south starts to push in tomorrow.  The clearing and drying process begins tomorrow with most of next week being dry, sunny and relatively warm throughout.   

 

24hr Precipitation ending at 4am: Today 24hr water: 2-3 snow: 2-6 Tomorrow’s 24hr water: .25  snow: 0 Trend and Timing: The precipitation will intensify through the day with over 2” of rain likely through the night. The precipitation begins to diminish tomorrow with the drying trend beginning.

24hr temperature ending at 4 am:  Low: 32   High: 45 Freezing level: 4500’-7000’ Trend and Timing:    Freezing levels will hover near 4500’ through the day and then spike up to around 7000’ tonight.  Surface temperatures will remain above freezing through at least Tuesday.

24hr Winds (mph) ending at 4am: Base: 5-10 ESE Ridge Top: 5-15 SSW Trend and Timing: Winds will be gusty and will shift southerly over the next 12-24hrs.

jM

MOUNTAIN WEATHER FORECAST

Time and Day: 0800 Friday

The Snapshot:  Snow showers today, moderate to heavy snow changing to rain tomorrow.

 

The Long Range: The week will start out dry with some sunshine on Monday and Tuesday.  Another system is expected to move through on Wednesday.

The Science:  Sorry, not enough time today to write a detailed forecast.  A significant rain-on-snow event is shaping up for tomorrow night into Sunday morning. – more on that tomorrow.   Enjoy the weekend.

 

24hr Precipitation ending at 4 am: Today 24hr water: .25 snow: 1-3 Tomorrow’s 24hr water: 3”  snow: 6-8” Trend and Timing: Light snow showers today.  Heavy snow changing to rain tomorrow.

24hr temperature ending at 4am:  Low: 28     High: 32 Freezing level:4000’ -  4500’ Trend and Timing:    Freezing levels are expected to hold around 4000’ through noon or so tomorrow.  Temperatures will then begin to rise tomorrow night with freezing levels peaking near 7000’ on Sunday.

24hr Winds (mph) ending at 4 am: Base: 0-10 W Ridge Top: 5-10 W Trend and Timing: Westerly winds today will begin to shift southerly tomorrow.

jM

MOUNTAIN WEATHER FORECAST

Time and Day:  0900 Wednesday

The Snapshot: Heavy rain begins today and continues through tomorrow night.

The Long Range:  Mixed snow and rain showers with some clear periods are expected on Friday with another strong warm frontal system developing over the weekend.  

The Science:  It is currently 32 degrees, 93% humidity with the barometer at 1012mb and trending down.  A triple point frontal system (warm, cold, occluded) will lift up from southwest today bringing with it heavy rain and rising temperatures.   A long stretch of moisture is being entrained with this system so expect a ton of moisture for the next few days.   The following cold front will begin to filter in the cooler air late tomorrow night. Freezing levels could drop to 4000’ or a bit lower by Friday night.   There could be a bit of snow accumulation on the ground Saturday morning but it is not likely to stick around.

Long range models have another similar wet, warm weather event expected to occur over the weekend.  Things begin to dry out early next week as the high pressure developing to the south should begin to nudge the moisture north.    

24hr Precipitation ending at 4 am: Today 24hr water: 1-1.25” snow: 0 Tomorrow’s 24hr water:  1” snow: 1-3” Trend and Timing: Rain will intensify today with the heaviest period after sunset tonight. The precipitation slowly diminished to light showers on Friday.

24hr temperature ending at 4 am:  Low: 32    High: 45 Freezing level: 4500’ – 7000’ Trend and Timing:    Freezing levels will peak at or above 7000’ tonight and then begin to slowly drop through the day tomorrow.

24hr Winds (mph) ending at 4am: Base: 5-15 SW Ridge Top: 5-20 SSW Trend and Timing: Gust SW winds can be expected for the next 24-36hrs.

jM

MOUNTAIN WEATHER FORECAST

Time and Day: 0900 Tuesday

The Snapshot:  A stormy week ahead. Wind and rain with some mixed snow today, dry tonight with another strong storm moving in tomorrow.

 

The Long Range:  Wednesday and Thursday will be very wet and windy with high freezing levels.  Cooler air arrives on Friday with snow possible heading into the weekend. 

The Science: It is 50 degrees this morning with the barometer at 1012mb and trending down. The leading edge of the approaching cold front is entering the northwest edge of the Olympic Peninsula.  The batch of moisture, out ahead of the front, will reach Stevens Pass shortly, with the main event happening around noon today.  The Puget Sound Convergence Zone is expected to develop, which will enhance the orographic effect for a few hours. Freezing levels are expected to drop to 5000’ in the wake of the cold front tonight with a short period of mixed snow possible.

The moisture will begin to taper off around sunset tonight as the pressure begins to rise and cooler air moves in.  A strong warm front hits tomorrow with rising temperatures, more wind, and heavy precipitation.

The Pacific Jet Stream keeps its focus on the PNW for the next 3-5 days with multiple storms poised to hit through the weekend.   

24hr Precipitation ending at 4 am: Today 24hr water:.5-.75  snow: Tomorrow’s 24hr water: 1-1.25  snow: 0 Trend and Timing: Water volumes have been downgraded by a .25” or so.  The precipitation diminishes to showers late this afternoon with tonight being mostly dry.  The next push of moisture arrives after 7 am tomorrow.

24hr temperature ending at 4 am:  Low: 34    High: 50 Freezing level: 7000’ – 4500’ – 7000’ Trend and Timing:    Freezing levels will briefly drop to 4500’ late this afternoon. Temperatures bounce back up tomorrow with freezing levels peaking at 7000’.

24hr Winds (mph) ending at 4am: Base: 5-15 WSW Ridge Top: 10-30 W   Trend and Timing: A high wind watch will be in effect today with 40+mph ridge top winds likely.  These are frontal winds so they should diminish as the front moves east of the mountains.

jM

MOUNTAIN WEATHER FORECAST

Time and Day: 1100 Monday

The Snapshot:  39 degrees with clear skies as of 11 am this morning. Clouds increase tonight with wind and rain beginning tomorrow morning. Some snow will be added to the mix tomorrow afternoon, but no significant accumulation is expected below 5000’.   

 

The Long Range:  Moderate to heavy rain continues into the weekend with things beginning to dry out early next week.   

The Science:  The skies are currently clear over Stevens Pass with the barometer at 1021mb and the RH at 50%.  A cold front, associated with a strong low-pressure system in the Gulf of Alaska, will slide down the Canadian coast over the next 24hrs.  The main action begins tomorrow morning with strong zonal westerly flow entering the mountains.  High winds and heavy precipitation can be expected tomorrow with a lull in the action tomorrow night.  A pocket of cooler air will briefly fill in behind the cold front for a period of mixed snow between 4000’ and 5000’.      

The jet stream will begin to sag south on Wednesday pulling in warmer air and a long fetch of moisture. Heavy rain with freezing levels peaking around 8000’ can be expected Wednesday night into Thursday.   

Storm totals for the week = +-5” of rain with little to no snow accumulation below 4500’. 

 

24hr Precipitation ending at 4am: Today 24hr water: .10  snow: 0 Tomorrow’s 24hr water: 1+  snow: 0-2 Trend and Timing: Light rain begins after 4 am tomorrow and increases through the day.  Mixed snow can be expected tomorrow afternoon with a brief dry period tomorrow night.

24hr temperature ending at 4 am:  Low: 30    High: 45 Freezing level: 7000’ – 4500’ Trend and Timing:    Freezing levels will drop to 4500’ tomorrow afternoon and then trend back up to 7000’ plus on Wednesday.

24hr Winds (mph) ending at 4 am: Base: 5-10 W  increasing tomorrow Ridge Top: 5-15 W Trend and Timing: Winds will begin to strengthen early tomorrow morning with strong post-frontal winds likely tomorrow afternoon.  40+mph gust will be possible along the ridgetops.  The wind quickly diminishes and shift SW on Wednesday.

jM