November 30, 2016

8:00 start Dec 1st no abs

MOUNTAIN WEATHER FORECAST

Time and Day: 0700 Wednesday

The Snapshot: Snow and wind today, snow tapering to showers tonight, light snow with sun breaks tomorrow, more snow on Friday and Saturday.  Much cooler and dry for the start of next week.

The Science:  The advertised storm arrived right on time with around 2” of snow thus far this morning. Once the approaching occluded front passes east of the mountains, the winds will shift westerly and strengthen.  The snow should be consistent with good upslope orographics through the day. The Puget Sound Convergence zone will likely be south of Stevens.   The snow will begin to diminish tonight as an upper-level ridge between storms moves in.  Therefore, expect light snow with partial clearing to greet the day tomorrow.  

The Long Range: A progressive warm front enters the region on Friday.  Heavy precipitation (snow) is expected for the weekend.  A cold dry air mass fills in behind the weekend storm that will likely produce the coldest temperatures of the season thus far.  There is another storm in the works for the middle of next week.    

Precipitation Ending at 4am:

Today 24hr water = .75  Snow = 5-8

Tomorrow’s 24hr water = .24  snow = 1-3

Trend and Timing:
Snow will be consistent through the day and turn to light showers overnight.


24hr temperature ending at 4 am tomorrow: 
                                     
Low: 27    High: 32
Freezing level: +-4000’

Trend and Timing:   
Freezing levels will remain around 4000’ with normal night time cooling.  

 
24hr Winds (mph) ending at 4 am tomorrow:
Base: 0-10 W
Ridge Top: 10-15 W gusty

Trend and Timing:
The wind will shift westerly and strengthen this morning.  Watch for ridge top winds with gust +25pmh at times.



jM

November 29, 2016

8am Start Wednesday, November 30 NO ABS

Great way to start the season, skiing POW! Good job everyone getting the show up and running today.

-253

Mountain Weather Forecast

Time and Day: 9:00 Tuesday

The Snapshot: Dry and mild today, partly cloudy. Snow starting early Wednesday morning becoming moderate to heavy Wednesday afternoon and evening.

The Science: A transitory high pressure ridge will move across Washington State today during the daylight hours, with the next low pressure trough and associated front directly on its heels. After the front crosses the Cascade Crest early Wednesday morning, the mid and upper level flow will be favorable for supporting orographic snow showers at Stevens Pass. A Puget Sound Convergence Zone looks likely to set up, the question is whether it will be positioned over Stevens Pass, or further south.

The Long Range: Thursday provides a relative break in the active weather, looking mostly dry currently. Friday brings a weakening system with slightly rising freezing levels (~4,000”). The next one to watch is Saturday night/Sunday, which currently looks like a good snow producing event for the Washington Cascades.


Precipitation Ending at 4am:

Today 24hr water =.10 Snow = 0-2”

Tomorrow’s 24hr water = .75-1.0   Snow = 8-10”

Trend and Timing: Light snow beginning early Wednesday morning, intensifying during the day, becoming moderate to heavy Wednesday afternoon/evening.

24hr temperature ending at 4 am tomorrow: 
                                     
Low: 27    High: 32
Freezing level: 4000’, then 3,000’

Trend and Timing:   
Daytime temps should peak this afternoon ahead of the front, rapid cooling early Wednesday morning.
 
24hr Winds (mph) ending at 4 am tomorrow:
Base: W 5mph, then E 5-10
Ridge Top: SSW 5-10, then S 10-15

Trend and Timing:
 Light west winds should give way to east flow through the passes Tuesday afternoon.

DV

November 28, 2016

7:00am Start, Tuesday November 29th


MOUNTAIN WEATHER FORECAST

Time and Day:  0700 Monday

The Snapshot:  Windy, cooler with diminishing snow showers today, more snow expected tomorrow night with the week ending dry.

The Science:  It looks like we have received around 11” so far this morning with a few more on the upper mountain – nice.   The frontal system that brought the snow is now heading into the intermountain west (Idaho, Montana).  Strong NW flow is filling in and will bring a windy day with snow showers beginning to taper off tonight.  

The next front is now timing out to arrive early Wednesday morning.  Storm totals for this system are +-.5” of water 3-5” of snow.   Thursday and most of Friday will be dry with clear period due to building high pressure. 

The Long Range:  Another series of storms are in the works for the weekend. The first is currently timing out to arrive sometime late Friday and then another on Sunday.  Models disagree on the timing and strength of these storms so no need to dwell on any details just yet.

Precipitation Ending at 4am:

Today 24hr water = .25 Snow = 2-4

Tomorrow’s 24hr water = .25-.5 snow = 3-6

Trend and Timing:
Snow showers slowly taper off today.  Tomorrow will be mostly dry with a few light snow showers possible.   The next front hits late Tuesday night or early Wednesday morning.


24hr temperature ending at 4 am tomorrow: 
                                     
Low:  26   High: 30
Freezing level: +-3500’

Trend and Timing:   
Temperatures will fall into the mid to upper 20’s today.  Freezing level will be around +-3500’ through tomorrow. 

 
24hr Winds (mph) ending at 4 am tomorrow:
Base: 5-10 NW
Ridge Top: 5-15 gusts 20+

Trend and Timing:
Gusty NW winds will persist today.




jM

November 27, 2016

MOUNTAIN WEATHER FORECAST

Time and Day: 0700 Sunday

The Snapshot:  Light precipitation today with moderate to heavy snow, wind and cooler tonight, diminishing snow showers tomorrow with another storm developing Tuesday night.  The week ends dry with clearing.

The Science:  A triple point (warm, cold, occluded) frontal system  approaching the PNW will bring a nice dose of snow to Stevens Pass tonight.  With some luck, Stevens could receive a foot of snow with enhanced  orographics and persistent snow showers tomorrow. 

The main action starts later today with the passing of the warm front.  Freezing levels will remain around 4000’ and even bump up a bit with the passing of the first front.  There could be a short Puget Sound Convergence period tonight, which could be the heaviest snow period. Snow totals will be dependent on where and how long the convergence zone decides to live.

The cold front quickly follows which will lower temperatures and turns the general flow to NW; this will likely shift the convergence zone south of Stevens.  The snow will slowly shift to showers tomorrow with a high pressure ridge moving in on Tuesday.
  
The Long Range:  Long range models are being very fickle, so confidence is low with the +- 7 day outlook.  As of this morning, Tuesday’s storm appears to be gaining some energy and should produce some more snow.  High pressure will likely bring a few days of dry weather for end the week.   

Precipitation Ending at 4am:

Today 24hr water = .75-1 Snow = 7-12

Tomorrow’s 24hr water = .25-.5  snow = 3-5

Trend and Timing:
Light mixed rain and snow showers today, main precipitation hits after 4pm, snow showers persisting tomorrow. 


24hr temperature ending at 4 am tomorrow: 
                                     
Low: 27    High: 34
Freezing level: 4000’  3000’

Trend and Timing:   
Freezing levels will stick around 4000’ today and then fall in the wake of the cold front later tonight. 

 
24hr Winds (mph) ending at 4 am tomorrow:
Base:  5-10 W
Ridge Top: 5-15 NW

Trend and Timing:
Winds will intensify tonight with gusty NW flow for the next 24-48hrs.




jM

November 26, 2016

MOUNTAIN WEATHER FORECAST

Time and Day: 0830 Saturday

The Snapshot:  Snow today diminishing to light snow showers overnight.  More snow arrives tomorrow night with next week trending dry.

The Science:  Two low-pressure troughs will swing through the Cascade Mountains over the weekend.  Cooler temperatures, northwesterly flow with light to moderate snow will fill in behind these fronts.  A brief lull will occur overnight with the next frontal system arriving tomorrow night.  

The Long Range:  Long range model are now building a high pressure ridge over the PNW starting on Monday.  This is a significant change in the forecast models and they don’t sync up very well.  So as of now, with the exception of a weak system moving through on Wednesday night, next week will be mostly dry.

Precipitation Ending at 4am:

Today 24hr water = .25  Snow = 1-3

Tomorrow’s 24hr water = .5 snow = 3-5

Trend and Timing:
Light rain and snow today below 4500’.   The precipitation will diminish tonight with the next wave of snow arriving after 4pm tomorrow afternoon.


24hr temperature ending at 4 am tomorrow: 
                                     
Low: 26    High: 34
Freezing level: +-4500’  - 3500’

Trend and Timing:   
Freezing levels will fall overnight as NW flow develops. 

 
24hr Winds (mph) ending at 4 am tomorrow:
Base: 0-5 E
Ridge Top: 0-10 ESE

Trend and Timing:
East flow will persist today and slowly shift westerly tomorrow.




jM

November 25, 2016

MOUNTAIN WEATHER FORECAST

Time and Day: 0700 Friday

The Snapshot:  Light snow showers with sun breaks today, snow tonight with mixed snow and rain showers tomorrow, dryer with some clear periods on Sunday, more snow on the way next week.

The Science:  Telemetry says somewhere in the neighborhood of 7-11” of snow fell during the last 24hrs. A low-pressure trough that has formed off the Washington coast will spin the next band of moisture up through the state tonight. This will be followed by another weak ridge high pressure for a repeat of today on Sunday with snow developing late Sunday night. 

The Long Range:  Unstable NW flow will keep this pattern of a storm every other day or so coming; Sunday/Monday and then again late Tuesday night, all should be good snow producers for Stevens Pass.

Precipitation Ending at 4am:

Today 24hr water =  .25 Snow = 1-3

Tomorrow’s 24hr water = .25-.5 snow = 2-5

Trend and Timing:
Snow after 7pm tonight.  Snow with a chance of rain in the base area early tomorrow morning.  The precipitation tapers off late tomorrow afternoon with Sunday trending dry.


24hr temperature ending at 4 am tomorrow: 
                                     
Low: 30    High: 34+
Freezing level: +-4500’

Trend and Timing:   
Freezing levels will remain steady around 4-4500’.   Sun breaks today could push surface temperatures above freezing.   Pockets of warm air will move through tomorrow which could temporarily bump up temperatures.   

 
24hr Winds (mph) ending at 4 am tomorrow:
Base: 0-10 E  
Ridge Top: 5-10 ESE

Trend and Timing:
Winds will be mostly E with southerly flow aloft.  Winds will shift westerly with the passing of the fronts. 




jM

November 24, 2016

MOUNTAIN WEATHER FORECAST

Time and Day: 0830 Thursday

The Snapshot:  Snow today, snow diminishing overnight, relatively dry tomorrow with snow expected on Saturday.  More storms on the way next week.  

The Science:  This morning’s radar has the leading edge of an approaching cold front entering the Olympic Peninsula.  Snow will intensify as the front marches east.  Another pulse of moisture will push up from the south tonight with a short period of some rain in the mix; this should be short lived if at all.  Freezing levels will be around 4000’ so the snow will be wet and heavy.   Good base making.   

Pressure gradients will ease with some mid level ridging tomorrow which will bring and end to the steady precipitation and even produces some clearing. A weak low-pressure system will swings through on Saturday with few more inches of snow possible during the day.  

The Long Range: Saturday night and Sunday will be mostly dry with partial clearing.  Active NW flow continues more snow for the final week of November.  

Precipitation Ending at 4am:

Today 24hr water = .75-1 Snow = 8-12

Tomorrow’s 24hr water = .25 snow = 1-3

Trend and Timing:
Snow has begun to fall; there will be a brief lull this afternoon with a pulse of heavy snow around midnight.  Snow quickly tapers off tomorrow with little snow expected after 7am tomorrow.


24hr temperature ending at 4 am tomorrow: 
                                     
Low:  28   High: 34
Freezing level: +-4000’

Trend and Timing:   
Temperatures will be consistent around 300 f through Saturday night.  Sun breaks could push temps up a few degrees tomorrow. 

 
24hr Winds (mph) ending at 4 am tomorrow:
Base:  0-10 E
Ridge Top: 5-10 ESE

Trend and Timing:
East flow at the surface with southeasterly flow aloft will continue into Saturday.




jM

November 23, 2016

NWAC Starting Avalanche Forecasts Thursday, November 24

AKA Thanksgiving. First avalanche forecast of the season should go out around 6:00pm tomorrow. NWAC is also currently issuing daily weather forecasts in the early afternoon until their regular winter schedule starts.

-253 Dan

MOUNTAIN WEATHER FORECAST

Time and Day: 0930 Wednesday

The Snapshot:  Light snow showers today, snow tomorrow, dry on Friday, more snow for the weekend.

The Science:  .25” of water with around 3” of snow fell overnight. Light snow showers have been left in the wake of the occluded front that moved east of the Cascade Crest earlier this morning.   Two, very close fronts, will move through the region starting early tomorrow.  The first should produce some nice snow for Stevens tomorrow.  A cut-off low with an embedded warm front forms behind the first wave and will swing north through the mountains tomorrow night.  Freezing levels will briefly spike up to near 5000’ as a pocket of warm air makes its way up the westerly slopes.  Therefore, expect a little mixed rain with the snow after sunset tomorrow.   The precipitation tapers off on Friday with some partial clearing.

Storm totals = 4am tomorrow – 4am Saturday = +-1.5” of water, 10-15” of snow.

The Long Range: A weak low-pressure system will track through on Saturday with more snow showers.  A more organized system arrives late Sunday with more snow for Stevens Pass to start the new week.   High pressure building off of western coast will begin to dry and warm things up for the middle of next week.

Precipitation Ending at 4am:

Today 24hr water = .25 Snow = 1-3

Tomorrow’s 24hr water = .75-1 snow = 6-10

Trend and Timing:
Light snow showers today, snow arriving early tomorrow morning (+-4am)


24hr temperature ending at 4 am tomorrow: 
                                     
Low: 29   High: 32
Freezing level: +- 4000’

Trend and Timing:   
Freezing levels will hover near 4000’ through tomorrow. 

 
24hr Winds (mph) ending at 4 am tomorrow:
Base:  0-5 W shifting E
Ridge Top: 0-10 W shifting E

Trend and Timing:
 Light westerly flow will shift easterly early tomorrow morning.




jM

November 22, 2016

MOUNTAIN WEATHER STAT UPDATE

Time and Day: 1000 Tuesday

Current models are not in agreement on the timing or intensity of these next few storms.  Therefore, confidence is low.  

Storm total numbers for the week:   

4pm today – 4pm tomorrow = .25 water,  2-4” snow

4pm Wednesday – 4pm Thursday  .5-.75 water  3-8”  snow

4pm Thursday – 4pm Friday  = .5” water 3-7” of snow

Low end of snow accumulation by 4pm Friday 8” -   high end 18” 

MOUNTAIN WEATHER FORECAST

Time and Day: 0800 Tuesday

The Snapshot:  Snow this afternoon, flurries tomorrow, snow on Thursday and Friday.

The Science:  The leading edge of the approaching frontal system has just made landfall and is expected to enter the mountains later today.   This approaching system has a fast moving warm front leading the charge but will be quickly followed by a cold front.  East flow should hold temperatures at or below 320 with freezing level falling in the wake of the cold front later tonight.  Snow will diminish overnight with snow showers persisting tomorrow. 

*I will post Thursday/Friday storm totals later today with fresh model data. 

The Long Range:   Cool unstable NW flow will keep the snow in the forecast through the weekend.  Another storm is starting to take shape for Sunday(?) with next week starting out dry and a bit warmer.

Precipitation Ending at 4am:

Today 24hr water = +.25 Snow =2-5

Tomorrow’s 24hr water = <.25  snow = 1-2

Trend and Timing:
Snow should begin this afternoon and taper off early tomorrow morning.  Tomorrow will have light snow showers with the next wave of moisture arriving Thursday morning.


24hr temperature ending at 4 am tomorrow: 
                                     
Low:  26   High: 34
Freezing level: 4000’   3000’

Trend and Timing:   

 
24hr Winds (mph) ending at 4 am tomorrow:
Base:  0-10 E shifting W
Ridge Top: 5-10 E shifting W

Trend and Timing:
 East flow will persist through the night and shift westerly tomorrow. 




jM

November 21, 2016

MOUNTAIN WEATHER FORECAST

Time and Day: 1000 Monday

The Snapshot:  Lights snow showers today with snow likely tomorrow night.   More storms with favorable temperatures arrive for the second half of the week.    

The Science:  This morning’s radar has scattered showers moving into the Cascade Mountains with freezing levels around 4500’.    Some weak upper-level ridging could allow the sun to peak through from time to time.

Cooler NW flow develops today with first of several frontal systems arriving tomorrow.   The frontal band is expected to stall a bit before progressing east.  Stevens won’t likely see any snow until late tomorrow.  This first storm isn’t packing much of a punch so only a few inches of snow is likely.  

The Long Range: The next front e.t.a.  is Thursday and then again on Friday.  These storms are packing more of a punch with good (snow) freezing levels remaining in place into the weekend.   

Early storm total estimates from 4pm Tuesday through 4pm Friday = 10-16” of snow.

Precipitation Ending at 4am:

Today 24hr water = <.25  Snow = trace

Tomorrow’s 24hr water = +.25 snow = 2-4

Trend and Timing:
Light snow flurries today with sun break.  Snow arrives after 2pm tomorrow.

24hr temperature ending at 4 am tomorrow: 
                                     
Low: 26    High: 30
Freezing level: +- 4000’

Trend and Timing:   
Freezing levels will hover around 4000’ through tomorrow.

 
24hr Winds (mph) ending at 4 am tomorrow:
Base: 0-5 W shifting E
Ridge Top: 0-10 W shifting E

Trend and Timing:
 Light westerly flow will shift easterly overnight and strengthen tomorrow.




jM

0800 Thurs March 28th, No ABS