January 31, 2014

start time 8:00 saturday

MOUNTAIN WEATHER FORECAST


Time and Day: 1000 Friday

The Snapshot: Light snow showers slowly diminishing through the day.  The weekend will be mostly dry with a few light snow showers possible.  


The Science:  A weak cold front that dropped through the region this morning will generate light snow showers and lowing temperatures.  A very cold air mass will settle over the region during the next few days.  Light snow showers with sun breaks will be on the weather menu for the weekend.


4-7day Long Range:  Next week will be dry and cold as another high pressure ridge develops.  Cold arctic air will flow in from Canada dropping temperatures into the single digits or lower by the middle of next week.

 
Precipitation:
Water by 4am = .10  Snow =0-1
24hr total inches of water ending at noon tomorrow =.10
24hr total inches of snow ending at noon tomorrow = 0-1
 
Trend and Timing:
Most dry with a chance of some very light snow showers through the weekend.
 
 
Base Temp and Freezing levels: 
Low: 14    High:  24
Freezing level: +- 1000’
 
Trends and Timing
Freezing levels will remain well below Pass level well into next week.
 
 
Winds (mph)
Base: 0-5 W
Ridge Top:0-10 W
 
Trend and Timing:
Light westerly flow will continue today and slowly turn northeasterly as the weekend progresses.
 

January 30, 2014

8am Start Time Friday

MOUNTAIN WEATHER FORECAST

Time and Day: 0900 Thursday

The Snapshot: Cooler with snow showers today.  Drying trend begins tomorrow.  

 
The Science:  The low pressure system that brought us this nice snow will weaken and drift east today leaving moderate to heavy snow showers in its wake.  The snow will slowly taper off tomorrow afternoon as high pressure builds off the western coast.


4-7day Long Range:  The weekend will trend dry under cool northwesterly flow. There will be a chance for occasional light snow showers passing through from time to time.  This pattern will persist into the coming week.



Precipitation:
Water by 4am =.5-.75  Snow = 6-8
24hr total inches of water ending at noon tomorrow = .75
24hr total inches of snow ending at noon tomorrow = +-8
 
Trend and Timing:
The Puget Sound Convergence Zone is expected to develop this today.  This should produce a 4-6hr period of heavy snow this afternoon and evening.  Snow will taper off early tomorrow morning.
 
 
Base Temp and Freezing levels: 
Low: 16    High: 28
Freezing level: 3000’      1500’
 
Trends and Timing
Freezing levels will continue to fall with low freezing levels continuing into the weekend.
 
 
Winds (mph)
Base: 5-10 W shifting E
Ridge Top: 5-15 W shifting E
 
Trend and Timing:
A period of gusty westerly winds will occur during the convergence period this afternoon.  Winds will diminish and shift easterly overnight.
 

 

January 29, 2014

6:15am Start Time Thursday

MOUNTAIN WEATHER FORECAST

Time and Day: 1130 Wednesday

The Snapshot: Finally some snow, and more on the way. 

The Science:  After enduring a spike in temperature today freezing levels will begin to fall. A low pressure system tracking through the region will keep the snow falling tonight with the precipitation gradually tapering off by the end of the week.


4-7day Long Range:   A dry, cool and partly sunny weekend is developing as our friend high pressure returns.   


Precipitation:
Water by 4am = .75”  Snow = 6-8”
24hr total inches of water ending at noon tomorrow = .75 -1
24hr total inches of snow ending at noon tomorrow = 8-10”
 
Trend and Timing:
The steady snow will begin to diminish late tonight with the early morning hours being mostly dry.  Expect intermittent snow through the day tomorrow.
 
 
Base Temp and Freezing levels: 
Low: 20    High: 34
Freezing level: 5000’      2500’
 
Trends and Timing
Freezing levels will begin to drop this evening with a cooler airmass settling over the region for the rest of the week.
 
 
Winds (mph)
Base: 0-5 W
Ridge Top: 5-15 W  
 
Trend and Timing:
Winds will remain westerly for the rest of the day.  Winds shift north than northeast tomorrow with east flow strengthening on Friday.
 

January 28, 2014

Start Time Wednesday---8am

MOUNTAIN WEATHER FORECAST

Time and Day: 1000 Tuesday

The Snapshot: Cold air from the east and warm air from the west will make for an interesting mix of precipitation today.  Expect snow tomorrow and Thursday.


The Science:  A warm front lifting up from the south will bring rising freezing levels and a mixed bag of precipitation today.  Another warm front followed by a strong cold front will push through tomorrow.   This will eventually lower freezing levels and change the precipitation to snow.


4-7day Long Range:  Snow showers with sun breaks are expected to continue into Friday.  With some luck, there could be +10” of snow by the weekend.  A cold stable air mass dropping in from the north will create a mostly dry and cold weekend.

 
Precipitation:
Water by 4am = .25  Snow = 2-4
24hr total inches of water ending at noon tomorrow = .5-.75
24hr total inches of snow ending at noon tomorrow = 4-6
 
Trend and Timing:
Mix snow and rain, freezing rain and other types of precipitation will continue through the night.   The main bulk of moisture will arrive after 7pm tonight and continue through tomorrow.   The moisture should turn to all snow through the day tomorrow.   
 
 
Base Temp and Freezing levels: 
Low: 24   High:  32
Freezing level: +-4500’
 
Trends and Timing
Freezing levels will hover near 4500’ through tomorrow.  East flow will help hold surface temperatures at or just below freezing.  Warm air aloft will contribute to the temperature fluctuations.
 
 
Winds (mph)
Base: 0-5 E
Ridge Top: 0-10 W
 
Trend and Timing:
East flow at Pass level with westerly flow aloft.  Westerly flow will strengthen tomorrow with +20mph ridge top winds likely.  
 
 

January 27, 2014

Why the Strange Weather?

Blame it all on the jet stream. Specifically the Omega Block (Ω)

When a persistent high pressure ridge forms over the west coast, the jet stream becomes so pronounced that it takes the form of the Greek letter omega, (Ω).   The overall weather pattern comes to a standstill, and the storm track, driven by the jet stream, cannot penetrate the block.  The result has been persistent warm and dry weather for most of the west coast. This is also the source of frigid temperatures and snow in Midwest and East.  The top of the omega ridge extends into the arctic north.  Cold air is then pulled with the jet stream as it dives south into the center of the country.

today's jet.  See the (Ω)?


The Good News.
The long term Jet Stream models have it flattening and becoming more west to east during the next 30days. If this comes true, the overall pattern will return to “normal”.   The current climate predictions reflect this trend.  

NOAA, Climate Trend Prediction of the West Coast:

1 - 15 days = below normal temperatures and below normal precipitation.  

30 -90 days = normal temperatures and normal precipitation.  
Time and Day: 0900 Monday

The Snapshot: Thickening clouds and colder with very light snow today; mixed rain and snow tomorrow.

 
The Science:  As expected, the high pressure ridge has weakened and shifted east.  This has opened the door for a low pressure system to reach the region.   Radar shows a stratus layer of clouds with light scattered snow showers entering the mountains this morning.  A strong temperature gradient divided by the Cascade Crest will build strong easterly flow through tomorrow.  A warm front followed by a cold front will create a mixed rain and snow event tomorrow with snow on Wednesday.   

 
4-7day Long Range:  The week will trend colder and dryer under developing northerly flow. 


Precipitation:
Water by 4am = .10  Snow = 0-1
24hr total inches of water ending at noon tomorrow = <.25
24hr total inches of snow ending at noon tomorrow = 1-3
 
Trend and Timing:
Light snow showers expected through the night with little accumulation.  Snow changing to mixed rain and snow tomorrow afternoon.
 
 
Base Temp and Freezing levels: 
Low:  22   High: 26
Freezing level: 2500’    3500’
 
Trends and Timing
Freezing levels are +- 2000’ east of the summit and +- 4000’ along the western slopes.  Freezing levels rise to 5000’ by tomorrow night.
 
 
Winds (mph)
Base: 5-10 E
Ridge Top: 5-15 ESE
 
Trend and Timing:
Strong easterly winds this morning will weaken later today.  East flow will continue through tomorrow and shift westerly early Wednesday.
 

Start Time Tuesday---8am

January 25, 2014

8:00 start sunday

MOUNTAIN WEATHER FORECAST


Time and Day: 1100 Saturday

The Snapshot:  Temperatures will rise into the 40’s today with sunny conditions continuing through the weekend.   Change is on the way.


The Science:  The high pressure is expected to weaken and shift east during the next 24hrs.  Cold arctic air dropping into the center of the country will also extend far enough west for a cooler temperature profile for the Cascades.  

 
4-7day Long Range: A westerly flow pattern takes shape for a more typical winter weather pattern next week.  The first moisture should reach the mountains on Tuesday with another system expected a few days later.   Freezing levels, with east flow influence, should be on our favor for snow.  Cooler NW flow develops during the ladder part of the week.   These systems aren’t packing much energy so significant snow is unlikely, but it is a change for the better.


Precipitation:
Water by 4am =0  Snow = 0
24hr total inches of water ending at noon tomorrow = 0
24hr total inches of snow ending at noon tomorrow =0
 
Trend and Timing:
No precipitation expected until early Tuesday morning.
 
 
Base Temp and Freezing levels: 
Low: 28     High: 44  
Freezing level: +- 6000’  
 
Trends and Timing
Freezing levels will rise above 6000’ today.  Cool air streaming in from the NW will drop freezing levels tomorrow night.
 
 
Winds (mph)
Base:
Ridge Top:
 
Trend and Timing:
The winds have shifted south westerly this morning. 

 

 

 

January 24, 2014

8:00 start saturday

MOUNTAIN WEATHER FORECAST

Time and Day: 0930 Friday

The Snapshot:  Abundant sunshine and warmer through the weekend.  Hope for some snow next week.


The Science:  A warmer air mass will move up from the southwest resulting in higher daytime temperatures for the weekend.  A shift from easterly flow to westerly flow and warmer temperatures should scourer out the inversion layers trapped in the valley on both sides of the crest.   


4-7day Long Range:  The long range models are starting to agree on a pattern change starting early next week.  The large cold air mass sinking into Montana will provide cooler air for eastern Washington; this should help with lowering freezing levels for the incoming moisture.  So for now, expect snow around the middle of next week.    


Precipitation:
Water by 4am = 0 Snow = 0
24hr total inches of water ending at noon tomorrow =0
24hr total inches of snow ending at noon tomorrow = 0
 
Trend and Timing:
0
 
 
Base Temp and Freezing levels: 
Low: 28    High: 44
Freezing level: 4500’      7000’
 
Trends and Timing
Freezing levels will rise to 7000’ or higher through the weekend.
 
 
Winds (mph)
Base: 0-5 E shifting W
Ridge Top: 0-10 ESE
 
Trend and Timing:
Light easterly flow will continue through the night with winds shifting westerly tomorrow.
 

8:00am Start for Friday 3/29/2024 No ABS

 Warm and dry weather is on the way.