MOUNTAIN WEATHER FORECAST

Time and Day: 12:00 am Monday

The Snapshot:   Mixed rain and snow showers are on the weather docket for today and tomorrow.   Another wave of moisture is expected on Wednesday with the week ending dry and warmer.  Any snow that does accumulate today will not likely stick around.  

The Science:  Heavy wet snow is currently falling with freezing levels around 4500’.  Storms riding on the northern jet stream will continue to track toward the PNW through the week.  However, a ridge of high pressure developing over the interior could create a blocking effect for the incoming storms later in the week.   Most of the moisture is likely to be pushed north into the BC coastal mountains.

The Long Range: The next wave of moisture will enter the mountains late Wednesday evening with Thursday and Friday trending dry due to the blocking ridge effect.  The offshore low-pressure system will dig pretty far south this week which equates to warmer air as part of the equation.   The models are pretty inconsistent from run to run. Therefore, confidence is fairly low.   

Precipitation Ending at 4am: Today 24hr water = .75  Snow = 1-2 base, 2-4 upper mountain. Tomorrow’s 24hr water =  .25-.5  snow = 1-2 Trend and Timing: Mixed rain and snow today shifting to intermittent showers tonight and tomorrow.

24hr temperature ending at 4 am tomorrow:                                        Low:  34   High: 38 Freezing level: 4500’  - 5500’ Trend and Timing:    Freezing levels will fluctuate between 4500 and 5500 feet through early Wednesday morning.  Freezing levels will be on the rise (+7000’) for the end of the week.

24hr Winds (mph) ending at 4 am tomorrow: Base:  5-10 W Ridge Top: 5-15 SW  gusty Trend and Timing: Gusty westerly flow will be the wind game today with the general flow turning southerly by the end of the week.   Winds will be gusty at times.

jM

MOUNTAIN WEATHER FORECAST

Time and Day: 10:00 am Wednesday

The Snapshot:  The mountains are draped in a soppy blanket this morning.  The radar has heavy rain falling along the western slopes with the higher elevations (+ 7000) getting some snow.  The rain will begin to shift showers tomorrow with intermittent rain showers persisting in the mountains through the weekend.

The Science:   Today’s heavy rain is being powered by a low-pressure system tracking up from the south.  The center of the low is currently just off the Oregon coast and is expected to track north into southern Canada over the next 12hrs.   A long SW fetch of moisture is in tow which is the main source of the rain today. The rain should turn to showers tomorrow as the storm heads into the Canadian Coastal Mountains tonight.   

The Long Range: The atmosphere will remain unstable, keeping the threat of rain in the discussion through the weekend.   Next week will start out mostly dry with a cooler air mass in the early development stages for mid to late next week. 

Precipitation Ending at 4am: Today 24hr water = +1” Snow = 0 Tomorrow’s 24hr water =  .25-.5 snow = 0 Trend and Timing: Moderate to heavy rain today tapering to showers after midnight tonight.

24hr temperature ending at 4 am tomorrow:                                        Low: 36    High: 48 Freezing level: +6500’ Trend and Timing:    Temperatures will remain on the mild side for the next few days with freezing levels at or above 6000’.

24hr Winds (mph) ending at 4 am tomorrow: Base: 5-10 E shifting S Ridge Top: 5-15 E shifting S Trend and Timing:  Some gusty easterly winds can be expected today with the general flow shifting southerly tonight.

jM

MOUNTAIN WEATHER FORECAST

Time and Day: 0930 Monday

The Snapshot:  Increasing clouds this morning with intermittent rain showers developing this afternoon and evening.  Tomorrow will be relatively dry with some light rain at times.  Expect moderate rain on Wednesday and Thursday.

The Science:  A low-pressure cell has decided to park itself just off the PNW coast and spin bands of moisture into the interior.  Thus, expect periods of rain, with dry periods in-between throughout the week.   The general flow will be southerly which will keep freezing levels above 5000’.  There may be a bit of light snow possible on the upper ridge overnight but no snow to speak in the long range outlook.

The Long Range:  Rain showers will remain in the forecast through the weekend.  The general temperature regime will remain seasonally normal with no out of the ordinary cold air influences expected.

Precipitation Ending at 4am: Today 24hr water = .10  Snow = 0 Tomorrow’s 24hr water = <.10 snow = 0 Trend and Timing: Light rain showers show up this afternoon with tomorrow trending mostly dry.

24hr temperature ending at 4 am tomorrow:                                        Low: 32    High: 44 Freezing level: +5000’ Trend and Timing:    There will be a bit of early morning cooling with daytime temperatures rebounding into the mid 40’s.

24hr Winds (mph) ending at 4 am tomorrow: Base:  5-10 E Ridge Top:  5-10 ESE Trend and Timing: Easterly flow at the surface with southerly flow aloft will be the wind game for the next 24-36hrs.

jM

WINTER CLIMATE

Below is a web site with a good video on La Nina winter climate prediction.

http://unofficialnetworks.com/2016/10/noaas-official-2016-2017-winter-weather-forecast

Enjoy

jM

MOUNTAIN WEATHER FORECAST

Time and Day:  0900 Wednesday

The Snapshot:  Today will be mostly dry with some clear periods, the rain machine begins again tonight with several storms in route to the PNW.  

The Science:  Storms being pushed by a strong NW jet stream will continue to track through the PNW for the next 5+ days.   Freezing levels will remain around their seasonal norm elevations - +-5000-7000’.    There will be periods of cold air providing some mixed snow in the base area, but for the most part, the snow line will remain at or above the upper ridge.  

The Long Range:  The weather will remain active well into next week with storms moving through every 12-24hrs. 

MOUNTAIN WEATHER FORECAST

Time and Day:  0900 Monday

The Snapshot:  One could say that the mountains are a bit soggy this morning.  The rain showers will linger in the mountains today and then slowly diminish over the next 24-36hrs.  Wednesday may be the nicest day of the week with more of rain expected on Thursday.  

The Science:  Unstable onshore flow, leftover from the weekend’s PNW Typhoon, will keep rain showers persisting through tomorrow.  A weak upper-level ridge will begin to break up the showers and allow some clearing to develop over the next few days.  This will also allow some cooler air to settle in with early morning temperatures dropping below freezing.       

The Long Range:   A warm front will bring more rain and rising freezing levels on Thursday.   The weekend appears to be dry with high pressure building off the west coast. 

Precipitation Ending at 4am: Today 24hr water = .25  Snow =  trace Tomorrow’s 24hr water = .10 snow = trace Trend and Timing: Rain showers slowly taper off through tomorrow.

24hr temperature ending at 4 am tomorrow:                                        Low:  36   High: 44 Freezing level: +- 4500 - 5000’ Trend and Timing:    Temperatures will hold steady for the next 24hrs.  Cooler Wednesday morning.

24hr Winds (mph) ending at 4 am tomorrow: Base:  0-5 W Ridge Top: 5-10 W Trend and Timing:  Light westerly winds today and tomorrow.

jM

STORM WATCH

An Impressive Storm:

Western Washington prepares for hurricane force winds and flooding rains. See below for an excerpt from this morning’s NWS discussion. 

So what can be Stevens Pass expected from this storm?   This storm is tracking south to north with most of the energy remaining west of the Cascade Crest.  This storm is also moving fast which tends to decrease the sustained rain events. Models have some upper level ridging behind the storm late tonight which could create some breaks in the precipitation tomorrow. The atmosphere will remain unstable enough to have rain showers in the forecast into early next week.  

Rain:  Water values for the Stevens are +-75” for the next 24hrs.  Compared to the coast, the rain will be relatively light in the mountains.  

Snow:  Snow levels this morning are around 4500’ with freezing levels 5500’.  Temperatures are on the rise with warm air accompanying this storm.  Freezing levels are expected to climb to 7000’ or higher this afternoon/evening and then drop back to +-5500 tomorrow.  The upper mountain has some nice snow on it from yesterday and will likely stick around for awhile.

Wind:  The winds will shift from east to south/southwesterly later today.  Stevens Pass is usually protected from strong south-southwest winds.  However, some models are forecasting 70+ mph winds hitting the coast - so the potential for damaging winds at Stevens Pass is there.

National Weather Forecast Discussion for 10/15 3am.

A powerful storm that will impact the area later today was

presently near 43N 132W at this time. Earlier, while frontogensis

was still occurring, a ship reported sustained winds of 45 knots

(52 mph) just west of the low center. This system continued to

strengthen and is forecast to near 970 mb before moving across or

in the vicinity of Cape Flattery. This is classic set-up for a

major windstorm for western WA, especially since it contains the

remnants of Typhoon Songda. Therefore, expect fairly widespread

high winds later today through this evening, especially over the

coast and areas north of Everett. The GFS MOS guidance has

sustained winds of 37 knots (43 mph) at Hoquiam late today and 41

knots (47 mph) at Oak Harbor this evening. Winds this strong,

accompanied by 60+ mph gusts, could cause quite a bit of damage.

The storm is fast-moving; therefore, wind should rapidly diminish

after midnight tonight.

The main concern is the potential for stronger winds than

currently forecast. The bent-back occlusion is expected to move

across the coastal waters, possibly clipping the far north coast,

later today through early this. There is a real possibility that

winds could reach hurricane force over parts of the coastal

waters, with 75 mph (or higher) over the adjacent land areas. Will

need to monitor this closely over the next few hours.

The air mass will become unstable behind the front late tonight

for isolated thunderstorms over the coastal waters. Expect showery

conditions on Sunday across the entire CWA. There may be a threat

of thunderstorms over the coast and southwest interior during the

day Sunday but confidence was not high; therefore, thunderstorms

were left out of the forecast.

La Nina Watch

Below is the monthly climate prediction statement:

The Gist:

La Niña is favored to develop (~70% chance) during the Northern Hemisphere fall 2016 and slightly favored to persist (~55% chance) during winter 2016-17

Neutral conditions are currently in effect with model predictions favoring the development of a weak La- Nina for the 2016/17 winter.

Enjoy

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/index.shtml

An impressive PNW Storm in the works:

The remains of a Pacific Typhoon will hit the PNW over the next 24-48hr.   Low pressure values in the 980 mb range with a strong fetch of moisture in tow, will create a nice storm stew of strong coastal  and mountain winds (+-65mph) and flooding water equivalents.  

Be safe out there. 

MOUNTAIN WEATHER FORECAST

Time and Day:   1300 Friday

The Snapshot:   The wind and rain will continue to batter the mountains through the weekend.   Dryer weather develops early next week.    

The Science:  The radar is lit up with heavy precipitation throughout western Washington.  Mixed rain and snow is falling around 5500’ with the snow line around 6500’.   Stevens Pass has received just under 3” of rain over the past 36hrs with an additional .75-1 possible today.   Along with the moisture, warm southwest flow will also push freezing levels to +- 6000’ over the next few days.

The Long Range:  Things begin to dry on out on Tuesday/Wednesday with high pressure expected to build over the PNW.  

Precipitation Ending at 4am: Today 24hr water = .75-1  Snow = 0 Tomorrow’s 24hr water = .75  snow = 0 Trend and Timing: Rain will continue today with intermittent showers persisting through the weekend.

24hr temperature ending at 4 am tomorrow:                                        Low: 36     High: 42 Freezing level: +6000’ Trend and Timing:    Temperatures will be warming through the next 24hrs.

24hr Winds (mph) ending at 4 am tomorrow: Base:  5-10 SW Ridge Top: 5-15 SW Trend and Timing:  Gusty SW winds today.  Winds shift easterly over the weekend.

jM

MOUNTAIN WEATHER FORECAST

Time and Day:  9:00 am Wednesday

The Snapshot:  Turning partly cloudy today with a series of heavy rain events starting tomorrow.  Clouds will begin to move in later today in response to the incoming weather systems.  It’s going to be wet for awhile.  

The Science: A large, powerful low-pressure system churning in the Gulf of Alaska will spin several storms through the PNW over the next 5 days or so. These storms are packing a punch with heavy precipitation and high winds for the Cascades Mountains. Freezing levels are expected to be above 5000’ through the weekend, so no snow likely at Stevens Pass.   Storm totals by the end of the weekend could exceed 5” of rain.

The Long Range:  The storms appear to keep right on coming into next week.   Freezing levels will be near seasonal norms (6-8k) through the middle of next week.   Therefore, no significant snow for Stevens in the long range outlook.  

Precipitation Ending at 4 am: Today 24hr water = .25 Snow = 0 Tomorrow’s 24hr water = 1-2”  snow =  0 Trend and Timing: Rain will begin sometime after midnight and increase tomorrow.

24hr temperature ending at 4 am tomorrow:                                        Low:  30   High: 50 Freezing level:  +5000’ Trend and Timing:    Temperatures will peak near 50 today with the aid of the sun.  Freezing levels are on the rise with snow levels being around 6500’ by tomorrow.

24hr Winds (mph) ending at 4 am tomorrow: Base:  0-5 E SE Ridge Top: 5-10 E SW Trend and Timing: Winds will be easterly and light today.  Strong SW winds will be associated with the approaching storms.

jM

MOUNTAIN WEATHER FORECAST

Time and Day:  Monday 10/10/2016

The Snapshot:   It’s wonderful to see snow on Cowboy Ridge.  This morning’s radar has dry conditions over most of the state with the recent weather system heading into northern Montana.   The week will start out dry with a clearing trend.  A series of storms arrives mid-week with another wet weekend ahead.  

The Science:  2.56” of water fell over the weekend with last night’s freezing levels dropping to around 5000’.  The barometric pressure is on the rise with the atmosphere stabilizing over the PNW during the next 24hrs.   Therefore, clouds should begin to break up today with mostly dry conditions prevailing.  We should see a bit more sunshine tomorrow with clouds developing on Wednesday.    

The Long Range:  A large low-pressure system developing in the Gulf of Alaska this week will drive another series of storms through the PNW starting late Wednesday night or early Thursday.   Early forecast models have the freezing levels between 6000’ and 8000’ through the weekend. 

Precipitation Ending at 4am: Today 24hr water = 0 Snow = 0 Tomorrow’s 24hr water =  0 snow = 0 Trend and Timing: Dry today and tomorrow.

24hr temperature ending at 4 am tomorrow:                                        Low: 28    High: 38 Freezing level: 4500.' Trend and Timing:    Freezing levels will hover around 4500’ with early morning temps dropping below freezing.  Daytime temps will recover into the low 40’s tomorrow.

24hr Winds (mph) ending at 4 am tomorrow: Base: 0-5 NW Ridge Top: 0-10 WNW Trend and Timing: Light northwesterly winds today shifting easterly tomorrow.

jM

MOUNTAIN WEATHER FORECAST

Time and Day:  9:00 Thursday.

The Snapshot: Light rain showers with partial clearing today, heavy rain begins tonight with a potential wet weekend ahead.  Snow in the higher elevations (+5500’) likely tonight.  

The Science:  Some weak mid-level ridging will create a relatively quiet weather day today.  A strong, fast-moving low-pressure system will hit the coast today with heavy precipitation and wind heading into the mountains tonight.  This system will mix with some cold air as it compresses against the mountains, so snow above 5500’ with mixed rain and snow at Stevens will be possible.   The storm will quickly move through overnight with intermittent showers left in its wake tomorrow.

The weekend could be rather wet at Stevens Pass with a steady flow of precipitation making its way into the Puget Sound Convergence Zone.  Freezing levels rise to 8000’ on Saturday so any snow accumulation will quickly liquefy.  Models disagree on where the Convergence Zone will settle, the bulk of the moisture could be pushed north, time will tell. 

The Long Range:   Next week will start out dry with another series of wet storms arriving mid-week.

Precipitation Ending at 4am: Today 24hr water = .5  Snow = trace Tomorrow’s 24hr water = .25 .5snow = trace Trend and Timing: Mixed snow and rain arrive after sunset tonight.  Heavy rain expected overnight with intermittent showers tomorrow.

24hr temperature ending at 4 am tomorrow:                                        Low: 36    High: 44 Freezing level: +- 5500’ Trend and Timing:    Temperatures will hover near 400f  through the night with early morning lows in the mid 300f .

24hr Winds (mph) ending at 4 am tomorrow: Base:  0-10  E shifting W strengthening Ridge Top: 5-10 SW strengthening Trend and Timing:  A high wind advisory will begin early tomorrow morning with SW ridge top winds +50mph possible.

jM