MOUNTAIN WEATHER FORECAST

Saturday 0830:

The Snapshot: Drying and cold; clearing today and tomorrow.

The Science:  The light snow showers will taper off today as pressure gradients begin to rise. Cold air will continue to flow in from the north for the next few days, dropping temperatures into the teens.    

4-7day Long Range: The week will start out dry with more storms entering the scene toward the end of the week.  Models disagree on long-term details so stay tuned as those develop.  

24hr precipitation ending at 4am tomorrow: Water = .10  Snow = 1-2 Trend and Timing: Snow will end today.

24hr temperature ending at 4am tomorrow:  Low: 14   High: 20 Freezing level:  +-1000’ Freezing Level Trends and Timing: Low freezing levels will stay around through the weekend.  Daytime surface temperatures will likely rise into the low 20’s with the aid of the sun.

24hr Winds (mph) ending at 4am tomorrow: Base: 0-10 E Ridge Top: 5-15E Trend and Timing: East flow will continue into early next week.

MOUNTAIN WEATHER FORECAST

0700 Friday:

The Snapshot:  Rain changing to snow today, sun tomorrow. The upcoming week will be mostly dry and sunny.  

The Science:  A strong cold front will swing through the region this morning with cold air from the north in tow.  Freezing levels will quickly drop and the rain will turn to snow with the passing of the front.   Depending on the timing of the front and how it interacts with the moisture stream will determine how much snow will be leftover.  A high-pressure cell dropping south from Canada will bring sunshine and cold and dry conditions to the Cascade Mountains tomorrow. 

4-7day Long Range:  Next week will start out clear, cold and dry with warming by midweek week.  No significant precipitation is expected throughout the week.   

24hr precipitation ending at 4am tomorrow: Water = 1”  Snow = 6-10” Trend and Timing: The rain is expected to change to snow around 10am this morning.   Snow will fall through most of the day and change to light snow showers this evening.

24hr temperature ending at 4am tomorrow:  Low: 20   High: 40 Freezing level: 5000’   1000’ Freezing Level Trends and Timing Freezing levels will descend below 4000’ this morning and continue to drop to 500’ by tomorrow afternoon.

24hr Winds (mph) ending at 4am tomorrow: Base:  5-10 NW Ridge Top:  5-15 NW Trend and Timing: Winds will shift NW and then eventually east during the next 24-36hrs.

JM

MOUNTAIN WEATHER FORECAST

0700 Thursday:

The Snapshot:  Rain today, snow tomorrow, dry over the weekend.  

The Science: The rain will continue today under a moist unstable airmass.  A strong cold front sweeps through the state tomorrow, hopefully, leaving +-10” of snow on the ground by early Saturday morning.  Dry cold arctic air flows in through the Frazer River Valley on Saturday; this will bring sub-freezing temperatures to the North Cascades Mountains.

4-7day Long Range:  Saturday through early next week will be dry and cold.  Next week looks mostly dry with warming towards the end.

24hr precipitation ending at 4am tomorrow: Water = 1   Snow = 0 Trend and Timing: Rain today changing to snow after 7am tomorrow.

24hr temperature ending at 4am tomorrow:  Low: 36    High: 42 Freezing level:  6000’    5000’ Freezing Level Trends and Timing Freezing levels drop below 4000’ by mid-morning tomorrow.

24hr Winds (mph) ending at 4am tomorrow: Base: 5-15 WSW Ridge Top: 10-20 WSW Trend and Timing: Gusty WSW winds today, diminishing tomorrow and shifting N.

MOUNTAIN WEATHER FORECAST

0700 Wednesday:

The Snapshot:  Intermittent rain showers today with another round of heavy rain tomorrow; cooler and drier by the weekend.  

The Science: An upper-level ridge has brought an end to the main water tap with only intermittent rain showers left over.  The next front arrives tomorrow morning with another fetch of warm moisture in tow.  An additional 2-4” of rain will be possible.  Freezing levels will remain high through mid day on Friday.   

4-7day Long Range:  High-pressure developing in southern Canada will bring a pattern change starting on Friday.  Cold air will flow into the PNW from the north over the weekend.  Low temperatures will likely cover everything in ice.  A warm front (Monday ish) lifting up from the south is starting to enter the scene.  Hopefully, this will mix well with the cold air and be our next best chance for snow.    

24hr precipitation ending at 4am tomorrow: Water = .25-.5  Snow = 0 Trend and Timing: Light rain showers will continue today.  The next front arrives early tomorrow morning with another round of heavy rain.

24hr temperature ending at 4am tomorrow:  Low: 36   High: 44 Freezing level: +-7000’ Freezing Level Trends and Timing Above freezing temperatures will continue through mid day on Friday.

24hr Winds (mph) ending at 4am tomorrow: Base: 0-10 SW Ridge Top: 5-15 WSW, gust +20 possible. Trend and Timing: Gusty westerly flow will continue for the next few days.  Winds shift SW this afternoon.

MOUNTAIN WEATHER FORECAST

0630 Tuesday:

The Snapshot: Windy and rainy today with a little snow mix in from time to time.  Rain ends tomorrow morning with another round on Thursday/Friday.   

The Science:   Strong moist westerly flow has brought high winds and warm rain to the PNW.  A brief pocket of cold air will bring a period of mixed snow to the upper mountain this morning.  There will be a break in the rain tomorrow; the flow shifts SW on Thursday driving another strong warm front through the region.  

4-7day Long Range:  4-6” of rain will be possible by early Friday morning.  Cooler and drier weather is expected by the weekend.

24hr precipitation ending at 4am tomorrow: Water = 1-1.5  Snow = 1-4 Trend and Timing: There may be a short period of snow this morning, mainly above 4500’.  Heavy rain will taper off early tomorrow morning.

24hr temperature ending at 4am tomorrow:  Low: 34   High: 46 Freezing level: 5000’   6500’ Freezing Level Trends and Timing Freezing levels will continue to rise today and tomorrow.  Above freezing temperatures will stay around until the end of the week.

24hr Winds (mph) ending at 4am tomorrow: Base: 10-20 W Ridge Top: 15-25 W   Trend and Timing: Strong westerly flow will create periods of high winds throughout the day.   Ridge top gust could top 50mph at times.

MOUNTAIN WEATHER FORECAST

0600 Monday:

The Snapshot:  Prepare for a very wet and windy start to the week.

This morning’s radar shows just some light snow showers lingering in the mountains.  Today will start out dry with snow returning this afternoon.  Heavy rain and high winds will start late tonight and last through Thursday.

The Science:  A high-pressure system off of the coast of California and a low-pressure system in the North Pacific, with act like a cog in a gear wheel to drive a ton of warm air, wind and moisture into the PNW.  Freezing levels will rise to near 5000’ tonight and peak at or above 7000’ by Wednesday. Hydrological numbers are impressive with 4-6” of rain possible by late Wednesday night.       

4-7day Long Range:  Above freezing temperatures and rain are expected to be around until early Friday morning.  The weekend trend is dry and cold. 

24hr precipitation ending at 4am tomorrow: Water = 1+   Snow = 1-3 Trend and Timing: Snow with start this afternoon and change to rain around 10pm.  A short period of mixed rain and snow will occur tomorrow morning and then turn to solid rain later in the day.

24hr temperature ending at 4am tomorrow:  Low: 32   High: 45 Freezing level: 3500’  5500’ Freezing Level Trends and Timing Temperatures will slowly rise through the next 24hrs with highs reaching 40f+ during the night.   Freezing level will rise above 6000’ tomorrow and higher on Wednesday.

24hr Winds (mph) ending at 4am tomorrow: Base: 5-20 WSW Ridge Top: 10-20 WSW Trend and Timing:  Light SW winds will strengthen and shift more westerly tonight.  A high wind advisory will be in effect tonight with 40+knot winds likely through most of tomorrow.

JM

SUNDAY WEATHER BRIEF

Sunday 3:30p,

Thanks to the convergence zone we could get an additional 2-4” on top of what has already fallen today.  Snow ends around midnight tonight.   The next front arrives tomorrow afternoon that will start out as snow (1-3” ) snow turns to rain through the night, heavy rain Tuesday – Thursday morning. 

Freezing levels are expected to rise to 5000’ late tomorrow night, 6500’ on Tuesday and then peak at or above 7000’ on Wednesday and stay high through late Thursday night.  

Water equivalents are impressive:   4-8” of rain Tuesday through Thursday.   Yikes. 

MOUNTAIN WEATHER FORECAST

0600 Saturday:

The Snapshot: 11” (according to the telemetry) over night, not a bad start.  The wet heavy stuff makes for a good base.  Temperatures will cool a few degrees today with gusty winds and snow showers.  More snow tomorrow, with significant warming early next week.

The Science: The spike in temperature was a bit delayed but did happen just after 10pm last night.  Strong westerly flow under an unstable air mass will keep light to moderate snow showers falling for the rest of the day.   

Tomorrow’s storm:   The next front is expected to hit the west slopes early tomorrow morning.  This will bring another round of wet heavy snow with an additional foot possible.  The precipitation will get cut tomorrow night by a building high pressure ridge.  Monday starts out dry with rising freezing levels.

4-7day Long Range:   Heavy rain, high winds and freezing levels around 8000’ can be expected on Tuesday and Wednesday.  Temperatures could hit 50f late Tuesday and Wednesday.  Significant cooling with little to no moisture is expected for the second half of the week.  Models are inconsistant with these details so stay tuned as the new week approaches. 

24hr precipitation ending at 4am tomorrow: Water = .5   Snow = 3-5 Trend and Timing: Light to moderate snow showers slowly diminish today.  Tonight will be relatively quiet with the next front entering the mountains early tomorrow morning, after 4am.

24hr temperature ending at 4am tomorrow:  Low: 28   High: 32 Freezing level: +-4000’ Freezing Level Trends and Timing Freezing levels will hover near 4000’ through early tomorrow morning.   Temperatures will briefly spike up early tomorrow morning and then slowly fall back to around 4000’ to finish the day.

24hr Winds (mph) ending at 4am tomorrow: Base: 5-15 W Ridge Top: 10-20 W, gusty.    Trend and Timing: Strong westerly winds will slowly diminish through the day. Winds will be lighter but still gusty with tomorrow’s storm.

 JM

MOUNTAIN WEATHER FORECAST

0900 Friday:

The Snapshot:  And So It Begins.  Today there will be strong winds, heavy snow and a touch of rain.   Snow showers persist tomorrow, then hit repeat on Sunday for high winds and more heavy snow.   

The Science: A triple point frontal system approaching the PNW will bring heavy precipitation and wind to the Cascade Mountains today.  The first warm front will spike freezing levels to 5000’ as it passes over.  The rise in temperature will be short lived with a strong cold front quickly following.  Thus, expect a short (1-2hr) period of rain below 4500’ sometime late this afternoon.  Freezing levels will drop to 4000’ in the wake of the cold front.  High westerly winds and the development of the Puget Sound Convergence Zone will enhance snow fall through the early morning hours. The occluded front will move through early tomorrow morning which will mark the end of the first wave of precipitation.   Snow showers continue tomorrow as cooler unstable air fills in behind the frontal system.  Another frontal system arrives on Sunday with more wet and heavy snow.       

4-7day Long Range:  Long range models are quickly changing for what will happen after the weekend –so confidence is low.  As of now, Monday will start out dry with moderate precipitation and rising freezing levels starting later in the day.   Heavy rain Monday- Wednesday is possible.  Hopefully, that will change.  +- 8000’ freezing levels are still forecasted on Wednesday with significant cooling by the end of the week.      

24hr precipitation ending at 4am tomorrow: Water =.75-1   Snow = 8-12” Storm totals by 4am Monday morning = 18-30” of snow. Trend and Timing: Light precipitation is now falling in the mountains with the main front over Puget Sound.  Snow at first with a 1-2hr period of rain this afternoon changing back to snow later tonight.  Convergence development will enhance snow fall around midnight.   Snow decreases in intensity early tomorrow morning but will continue.

24hr temperature ending at 4am tomorrow:  Low: 30   High: 36 Freezing level: 5000’    3800’ Freezing Level Trends and Timing Freezing levels will spike to 5000’ this afternoon.  Once the cold front moves through the freezing levels will fall to 4000’ or slightly lower.   East flow will play a part in the surface temperatures until the cold front moves through later today.

24hr Winds (mph) ending at 4am tomorrow: Base: 0-5 E shifting W Ridge Top: 0-10 E, shifting W, strengthening.    Trend and Timing: Easterly winds will hold until early this evening.  Strong westerly convergent winds will fill in behind the cold front this evening (7-10pm).  40 knot winds will be possible through most of the day tomorrow.