8:00 am start Sunday

STORM UPDATE

No significant changes in this morning’s forecast.   

The warm up is currently timing out to be between 4pm tomorrow and midnight – there shouldn’t be much precip (rain) during this period as it is between storms.   Temperatures begin to fall during the early morning hours on Monday with snow through most of the day.

Monday/Tuesday snow is looking better. 

John

MOUNTAIN WEATHER FORECAST

0700 Saturday:

The Snapshot: Dry with thickening clouds today, snow tomorrow, mixed rain and snow tomorrow night, snow on Monday, and rain ending the week.  

The Science: A low-pressure system developing off the western coast will push the high-pressure ridge east today.  This will allow a series of storms to pass through the region starting tomorrow.  Cool air will flow into the eastern basin today dropping freezing levels below 4000’.   Light snow will begin to fall late tonight with the main front arriving tomorrow.  Warm westerly flow will fill in behind the front tomorrow evening with mixed rain possible below 4500’.  A following cold front will arrive on Monday with PS Convergence Zone development and cooling – snow.  Storm totals below.

Models do not currently agree with timing or strength,  I will post a storm update later today with fresh data.

 

Long Range: It all comes to and end on Tuesday as another ridge of high pressure briefly builds.   A strong, moist frontal system with warm SW flow enters the scene on Thursday with rain ending the week.   

Precipitation ending at 4am: Today’s 24hr Water = .10   Snow = trace Tomorrow’s 24hr Water = .5-.75  Snow =  4-8” Trend and Timing: Light snow begins around midnight tonight but will not intensify until mid-morning tomorrow.  Snow changes to mixed rain and snow below 4500’ tomorrow evening.  Snow returns on Monday and continues through Tuesday morning.   48hr Storm totals:   4am Sunday -4am Tuesday = +2” water 8-16” of snow.

24hr temperature ending at 4am tomorrow:  Low: 24   High:  34 Freezing level: 5000’   3500’ Trends and Timing: Temperatures will fall today with freezing levels east of the crest dropping below 4000’.   Freezing level lift tomorrow afternoon to +-4500’.

24hr Winds (mph) ending at 4am tomorrow: Base: 0-5 E Ridge Top: 0-10 E   Trend and Timing: East flow will develop today and continue through tomorrow afternoon.  Winds shift westerly in the wake of the passing front tomorrow afternoon.

JM

Start Time Saturday---8am

MOUNTAIN WEATHER FORECAST

0630 Friday:

The Snapshot: There will be a few more days of clear and dry weather before the pattern begins to change on Sunday.  Got Snow?

The Science: This morning’s radar has a few high clouds but mostly clear over the region. A large low-pressure system developing in the North Pacific will break the high-pressure ridge down on Sunday allowing a series of systems to move through the region.   Freezing levels will bounce between 3000’ and 5000’ with east flow influence, so expect snow with periods of rain Sunday through Wednesday.    

Long Range: As of now, totals appear to be 4-8” of snow by 4am Monday, rain Monday changing to snow into Tuesday with an additional 4-8” of snow by early Wednesday morning.  Those totals will likely change as the storm develops but so far it is looking ok.   The week ends with warming and another mixed snow and rain event.   

Precipitation ending at 4am: Today’s 24hr Water = 0   Snow = 0 Tomorrow’s 24hr Water = 0 Snow = 0 Trend and Timing: Dry through Saturday night.

24hr temperature ending at 4am tomorrow:  Low: 28    High:  40 Freezing level: +- 6500’ Trends and Timing: Diurnal (24hr melt/freeze) temperatures swings will continue through early Sunday morning.

24hr Winds (mph) ending at 4am tomorrow: Base: 0-5 E/W Ridge Top: 0-10 NW   Trend and Timing: Surface flow will flip flop between easterly and westerly today. Light northerly flow aloft will eventually shift easterly tomorrow.

JM

Start TIme Friday---8am

MOUNTAIN WEATHER FORECAST

0700 Thursday:

The Snapshot:  Mostly clear and dry through Saturday. 

The Science:  A blocking ridge of high pressure will keep the PNW dry and mostly clear through Saturday.   Warm daytime temps, with cooling at night, will be the temperature regime.   These diurnal temperatures swings will make for good melt/freeze snow conditions.

Long Range:  The snow vs. rain game starts again as frontal system approaches the region on Sunday.  Models have been downgrading precipitation amounts with freezing levels between 4000’ and 5000’;   this is still a few days out so stay tuned as details get firmed up.    

Precipitation ending at 4am: Today’s 24hr Water = 0   Snow =  0 Tomorrow’s 24hr Water = 0 Snow =  0 Trend and Timing: 0

24hr temperature ending at 4am tomorrow:  Low: 26   High: 40 Freezing level: + 5000’ Trends and Timing: Good diurnal temperature swings through the end of the week.

24hr Winds (mph) ending at 4am tomorrow: Base: 0-5 E Ridge Top: 0-5 SE   Trend and Timing: Very light east-southeast flow today and tomorrow.

JM

Start Time Thursday---8am

MOUNTAIN WEATHER FORECAST

0700 Wednesday:

The Snapshot: Sunshine with cooling today, partly cloudy, but remaining dry for the rest of the week.

The Science: Most of the cloud cover has cleared out due to rising pressure this morning.   High clouds will move in tonight as another weak system brushes the NW corner of the state tomorrow.  A dry atmosphere with cooling will be the main pattern for the remainder of the week.

Long Range:  Models have the high pressure breaking down over the weekend with a chance of snow on Sunday/Monday.  Snow dances, please. 

Precipitation ending at 4am: Today’s 24hr Water = 0   Snow =  0 Tomorrow’s 24hr Water = 0 Snow =  0 Trend and Timing: 0

24hr temperature ending at 4am tomorrow:  Low: 24   High: 34 Freezing level: 4500’  3500’ Trends and Timing: Temperatures will fall but continue to be on the mild side of normal.

24hr Winds (mph) ending at 4am tomorrow: Base:  0-5 E Ridge Top: 0-10 SE   Trend and Timing: The gusty westerly winds experienced last night will fade and shift easterly today.

JM

Start Time Wednesday---8am

MOUNTAIN WEATHER FORECAST

0630 Tuesday

The Snapshot:  Light rain with slightly cooler temperatures today; dry tomorrow with light mixed rain and snow ending the week.

The Science:  A weak cold front will produce light rain showers today. Weak, unstable southwest flow will keep the threat of light precipitation and partial clearing in the forecast through the week.

Long Range:  A low-pressure system developing in the Gulf of Alaska will bring a pattern change late in the weekend. 

Precipitation ending at 4am: Today’s 24hr Water = <.25   Snow = 0 Tomorrow’s 24hr Water = .10  Snow = 0  Trend and Timing: Light misty rain is expected today, mostly dry tomorrow.

24hr temperature ending at 4am tomorrow:  Low: 36   High: 40 Freezing level: 6000’    5000’ Trends and Timing: Freezing levels will slowly drop during the next 36hrs.

24hr Winds (mph) ending at 4am tomorrow: Base: 5-10 W Ridge Top: 5-15 W   Trend and Timing: Gusty westerly winds will continue today.

JM

8:00 am start Tuesday

MOUNTAIN WEATHER FORECAST

0730 Sunday:

The Snapshot: Morning fog with clearing today and tomorrow, light snow Tuesday night and then again on Thursday.

The Science: A warm and dry airmass will continue to move into the PNW today.  Freezing levels could top 10,000’.   Morning fog should burn off to mostly clear skies.  A weak cold front will bring temperatures back to normal with a chance of light snow on Tuesday/Wednesday.  

Long Range:  Another weak system is expected on Thursday with a return to warm SW flow by the weekend.

Precipitation ending at 4am: Today’s 24hr Water =  0 Snow =  0 Tomorrow’s 24hr Water = 0 Snow = 0 Trend and Timing: No precipitation expected until Tuesday/Wednesday.

24hr temperature ending at 4am tomorrow:  Low: 40   High: 50 Freezing level: 10,000 Trends and Timing: Temperatures will continue to climb today and tomorrow.   Freezing levels are expected to fall back down to seasonal norms by Wednesday.

24hr Winds (mph) ending at 4am tomorrow: Base: 0-5 SW Ridge Top: 5-10 WSW    Trend and Timing: Southwesterly flow will continue today.

JM

8:00 am start monday

8:00 am start sunday

MOUNTAIN WEATHER FORECAST

0700 Saturday:

The Snapshot: Rain diminishing tonight, dry and warm tomorrow and Monday.

The Science:  Unstable, wet westerly flow will continue for most of the day.  High pressure lifting up from the south will push moisture north into Canada tonight.   A warm air mass will settle over the region with mild temperatures and clearing.   A weak frontal system will bring a chance of light rain on Tuesday/Wednesday.  

Long Range:  A blocking ridge forms off the coast toward the end of the week with cooler offshore flow developing.  No significant snow in the long range forecast.  

Precipitation ending at 4am: Today’s 24hr Water = .25   Snow = 0 Tomorrow’s 24hr Water = 0 Snow =  0 Trend and Timing: The rain is expected to end after 4pm this afternoon.   Dry tonight and tomorrow.

24hr temperature ending at 4am tomorrow:  Low: 40   High: 50 Freezing level: 8-10,000’ Trends and Timing: Mild temperatures will continue through Tuesday.

24hr Winds (mph) ending at 4am tomorrow: Base: 5-10 W Ridge Top: 5-15 W   Trend and Timing: Winds will weaken today with westerly flow continuing.

JM

Start Time Saturday---8am

MOUNTAIN WEATHER FORECAST

0630 Friday:

The Snapshot: Rain today and tomorrow with dry and warm weather finishing up the weekend.

The Science: 39⁰ this morning with light rain.  An approaching warm front will intensify the rain today; light showers will persist through  tomorrow. A warm air mass will settle over the region with high pressure building up from the SE on Sunday.

Long Range: Next week will start out dry and warm with another weak system tracking through on Wednesday.   

Precipitation ending at 4am: Today’s 24hr Water = .75    Snow =0  Tomorrow’s 24hr Water =.25  Snow =0  Trend and Timing: Rain today with showers lingering in the mountain for most of tomorrow.

24hr temperature ending at 4am tomorrow:  Low: 39   High: 48 Freezing level: + 6000’ Trends and Timing: Temperatures will continue to climb today with freezing levels possibly topping 10,000’ on Sunday/Monday.

24hr Winds (mph) ending at 4am tomorrow: Base: 0-5 E shifting W Ridge Top: 5-15 W   Trend and Timing: Gusty westerly winds will kick in later today with the passing of the front.

JM