Michaels Weather Blog

Flooding Rains and a Cascade Snowstorm.

2012-03-19T18:19:00.001-07:00

After a week of cold wet weather with a few snow showers on Sunday we are continuing this stubborn weather that just wont go away.

Starting tonight a big slug of moisture will begin hitting it us bring lots of rain through the next 2-3days.

So just how much rain? Well models are showing the 3 day rain fall totals reaching near the 3 inch mark. Now if that much rain will fall then there could be some serious flood threats to already high rivers.

The image below is the 3 day rainfall forecast ending Thursday morning

Now this rain will not be a warm pineapple express but instead a cold frontal 40 degree rain. The thing is this being a cold rain will mean snow up in the hills. Now a usual precip to snow ratio is 1 to 10 inches, which means 1 inch of rain is equal to about 10 inches of snow and if you look at the forecast rain totals above and change that to snow, places in the Cascades could get nearly 3 feet of snow in the next 3 days.

The image below shows the 24 hour forecast snowfall totals ending 5pm Wednesday

Ranging from 20 to 40 inches in spots!

Later in the evening on Wednesday as the cold front begins to move things could get interesting. Cold air advection will begin taking place and bottling up cold air along the west slopes of the Cascades. This will lead to lowering snow levels, now if the enough cold air bottles up it could lower the snow level down to the valley floor in the eastern part of the metro area, such as Battle Ground, Gresham, Oregon City, Camas...ect. But for now I am saying that we will only get a rain/snow mix with the snow level staying above 500ft.

Thanks for reading

-Michael

Historic Coastal Snow Storm

2012-03-13T19:17:00.000-07:00

What a wild few days of weather it has been! Lets start off with the wind.

Early Monday morning a deep low pressure rapidly developed and gave the coastal areas and some valley locations very strong winds.

The image below is a water vapor satellite image of the low

Here are some of the peak gusts recorded

- Pacific City (87mph)
- Garibaldi (82mph)
- Cape Foulweather (81mph)
- Clatsop Spit (81mph)
- Lincoln City (77mph)
- Cape Disappointment (75mph)
- Cannon Beach (65mph)
- Ocean Park (56mph)
- Salem (56mph)
- Eugene (51mph)
- Portland (49mph)
- Kelso (43mph)

Later on in the day the cold front passed the coast and started to drop the temperatures. Pretty quickly the rain began to turn to snow and stick. Meanwhile here in the Portland area we were getting heavy rain.

In the evening something almost unheard of happened, Lincoln city was getting dumped on with snow meanwhile Government camp was getting rain

Here are the ODOT images taken at the same time.

Now what caused this phenomenon to happen?

This was caused by a cold front stalling out just to the east of the Portland area and providing lots of moisture to the whole area, but the cold front stalling just to the east of the metro area caused the cold air at the coast not to be pulled in to our area until later when the front began moving again..

The image below shows the location of where the front stalled out (blue barbed line)

In fact so much snow fell on the cost that it will be one that goes down in the record books

So how much snow did fall?

Coast:

Tillamook: 8.5 inches

Newport: 6.0 inches

Waldport: 6.0 inches

Florence: 5.0 inches

Valley:

Happy Valley: 5.0 inches

Boring: 4.0 inches

Camas: 2.0 inches

Milwukie: 1.2 inches

Salem: 1.0 inch

SE Portland: 1.0 inch

Forecast:

The next several days are just going to be very wet, models are showing the jet stream taking aim directly at us and bringing us lots of moisture.

The image below is the NOGAPS model showing the jet stream on Thursday

On Saturday and Sunday another cold batch of air will come down, now snow is not looking likely due to the lack of precipitation with this cold air.

The image below shows the jet stream buckling and allowing the cold air to come down

My forecast:

Thanks for reading

-Michael

Coastal Bomb

2012-03-11T11:54:00.002-07:00

Tonight a major storm in the Pacific will develop very rapidly

Now this rapid intensification is called a meteorological bomb which means the pressure has dropped 24 millibars in 24 hours.

Here is an image of the low at 2pm Sunday

It might be hard to see but the small low is at 998 millibars

Here is that low 15 hours later heading toward Van. Island

Notice its down to 974 millibars! That is 24 millibars in 15 hours!

Now if this storm would come 100 miles more to the east then we would be in for a big storm here in the Portland area.

Here is the 12z WRF-GFS wind gust forecast

Notice how there are 70+ knot (80 mph) wind gusts along the coast...so if you want to go storm watching head on over to the coast tomorrow, as for us in the valley we will only receive a breezy 25 to 30 mph wind with a few gusts near 40 mph.

Thanks for reading

-Michael

Back to Stormy and Wet.

2012-03-08T21:30:00.001-08:00

Well I hope you enjoyed the last few days of sun because starting tomorrow night the rain is back.

Today was the warmest day so far in 2012, PDX officially hit 65 degrees with some places hitting near 70.

Now tomorrow as the day progresses clouds will roll in but the the front with the rain should hold till the overnight hours. After this front the jet stream will take aim directly at us.

The image below shows the jet stream taking aim at us on Saturday

As you can see the Jet stream delivers lots of moisture with it which gives us rain.

Now the catch is this jet stream is not moving anywhere, here it is again next Thursday

So just how much rain will we get?

Well the 12z WRF-GFS below gives us 1.5 inches of rain in 72 hours by Tuesday morning

Also on Monday a deep low pressure system will pas to our northwest giving the coast winds sustained near 60mph, now depending on how far west this low pressure will go will depend if the valley will get good wind.

The image below is the 00z WRF-GFS showing the low pressure producing winds of 50 knots of the coast.

My forecast:

Thanks for reading

-Michael

Weather Roller Coaster

2012-03-03T14:47:00.000-08:00

Last Wednesday night the forecast went wrong instead of having some light snow showers we got almost a widespread inch of snow with 2 inches in some places.

Now what went wrong?

Models were showing the big surface low moving off tho the east and drying us out, now that did happen but what models did not depict is that small little disturbance (called a vorticity maximum) would approach our area and give us steady precipitation.

The image below shows the little disturbance approaching our coast.

Now moving on to this week. After a warm and dry day on Sunday a cold front will come though our area on Monday afternoon and drop snow levels down to 500-1000ft once again

The best chance for valley snow will be after about 10 pm till Tuesday morning before the air drys out.

The image below shows the sharp cold front coming through on Monday afternoon

Now the following Wednesday high pressure will build over our area giving us possibly of first 60 degree day.

The image below is the 12z GFS ensembles showing the weather roller coaster then lots of disagreement beyond Friday.

My forecast:

Thanks for reading

-Michael

Update on Snow.

2012-02-28T17:25:00.001-08:00

As many of you heard already there is a chance of snow tonight and tomorrow.

Now this evening the chance of sticking snow is very low, however tonight around 11pm a cold front will come through and bring the snow levels down to about 500-1000ft

The Image below shows the placement of the cold front at 4:30pm

What to expect:

Now-11pm:

Rain/snow turning to all rain
Breezy winds becoming southerly

11pm-11am:

Rain/Snow showers becoming all Snow
Accumulations will stay mostly above 500ft
Accumulations below 500ft will be brief and only a trace -1 inch

12pm +

Snow showers will become rain/snow showers
T'storms will be possible as the air will be unstable

Long range:

In the long range models are in disagreement just look at the ensembles below some say warm weather other say it will stay cool

My forecast:

Thanks for reading

-Michael

A Snowy Update

2012-02-25T16:12:00.001-08:00

I'm sure most if not all have already seen some snow mixing in with rain today but its not over yet.

Info on snow:

Everyone will see snowflakes.
Best chance for snow will be tonight and Sunday morning
Spotty accumulations of a trace to1 inch
Accumulating snow will mostly stay above 500ft
Daytime highs 40-45
Sun breaks will melt any accumulated snow below 1000ft
Sunday evening moisture dissipates and leaves us dry
Monday will be cool and dry

Tuesday:

Now Tuesday morning models are not all in agreement on the position of a low but if that low does come far enough south then we would get an offshore flow which would give us a snow to rain transition.

The image below is the 12z WRF-GFS on Tuesday morning

Notice how the wind barbs circled in red are pointed offshore that indicated wind blowing from the east.

The image below is an explanation of the setup that we will have.

Now is this does setup right we could get 1-2inches of snow then rain. But if the low tracks farther north then we will get south winds and rain.

My forecast:

Thanks for reading

-Michael

Too Warm in the Lowlands for Snow.

2012-02-22T21:31:00.000-08:00

As I mentioned in the last post a trough of cold air is going to arrive over us this weekend.

Saturday the 25th

Now earlier this week models were supporting temperatures cold enough for snow down to sea level. however over the past few days models have warmed that cold air just slightly but enough to not give us snow.

The image below is the WRF-GFS cross section forecast

The dotted purple line is 32 degrees or freezing the solid blue line represents 1000ft, notice how the dotted line barely goes below the 1000ft mark.

Also when the coldest air arrives in Monday the air dries out and we have no precip.

So what will we see?

Snow levels 1000-1500ft
Possible rain/snow mix in showers Sunday night
NO ACCUMULATING SNOW in the valleys.
Scattered cold rain showers
Cold but dry Monday morning

My forecast:

Colder Weather Pattern with a Possibility of Snow?

2012-02-19T17:55:00.000-08:00

For the past few weeks we have been in a relatively warm and quiet weather pattern. Starting next week end a cold trough from the north will drop down and bring us cold air.

Now models are still disagreeing on exactly how cold the air will be but most are in agreement that it will be between -6 to -8c at 850mb (5000ft) over our area. now in the middle of winter -8c at 850mb will give you snow however during this time of year we would need about -9c to produce snow with an onshore flow.

2 Problems for snow:

1. Onshore flow:

The image below explains how onshore flow is a problem for snow.

2. Its the end of February:

At the end of February the sun angle is higher which gives us warmer temperatures.

Bottom line:

Snow level will be most likely be around 1000ft.
Best chance of brief accumulation at the valley floor would be Sunday morning.
Any accumulation would be spotty and brief.
this is one week away and it could change.

My forecast:

Thanks for reading

-Michael

One Last Grasp of Winter.

2012-02-16T18:18:00.000-08:00

As I explained in my last post that after we enter March our chances of lowland snow/arctic blast decreases dramatically.

However winter has decided to attempt to visit us one last time.

Saturday-Monday (18th-20th):

A trough of low pressure will arrive over our area and allow some cold air to seep into our region (shown below). Now this cold air will lower the 850 mb (5,000ft) temps down to about -6c which means the snow levels will be 1,000 ft to 1,500ft. Now the snow levels being up there does not rule out the chance of a rain/snow mix down to almost sea level in the heavier showers.

The image below is the 18z GFS ensembles showing the trough over our area on Saturday.

Tuesday-Thursday(21st-23rd):

A ridge of high pressure will build just to the west of us and give us drippy conditions.

The image below shows the 12z WRF-GFS showing the setup.

Notice how the high pressure gives us an onshore flow. Now what does an onshore flow do? Well it usually gives us lots of low clouds, fog, or drizzle. This is also known as a "Dirty Ridge"

Saturday+ (25th+):

Models are now starting to agree on that a trough of low pressure will drop down over us and drop snow levels down to 500-1500ft. However how low the snow level goes will depend on where the upper level high will be located.

The image below is the 12z Euro ensembles showing the trough bringing cold air to our region.

My forecast:

Timberline Forecast via NWS:

Friday: Snow, mainly after 10am. High near 34. Southwest wind between 17 and 21 mph, with gusts as high as 31 mph. Chance of precipitation is 90%. New snow accumulation of 2 to 4 inches possible.

Friday Night: Snow showers. Low around 19. Breezy, with a west southwest wind around 25 mph, with gusts as high as 40 mph. Chance of precipitation is 100%. New snow accumulation of 5 to 9 inches possible.

Saturday: Snow showers. High near 21. Wind chill values as low as zero. Windy, with a west wind between 26 and 30 mph, with gusts as high as 48 mph. Chance of precipitation is 100%. New snow accumulation of 6 to 10 inches possible.

Saturday Night: Snow showers. Low around 16. Breezy, with a west wind between 20 and 28 mph, with gusts as high as 45 mph. Chance of precipitation is 100%. New snow accumulation of 5 to 9 inches possible.

Sunday: Snow likely, mainly before 10am. Mostly cloudy, with a high near 26. Chance of precipitation is 70%. New snow accumulation of 1 to 2 inches possible.

Sunday Night: Snow likely. Mostly cloudy, with a low around 20. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.

Washington's Birthday: A chance of snow showers. Mostly cloudy, with a high near 30.

Monday Night: A chance of snow. Mostly cloudy, with a low around 22.

Thanks for reading

-Michael

Is Winter Over?

2012-02-11T19:15:00.000-08:00

Well the answer on the calendar is no, but meteorologically it might be over, let me explain.

Here in the Pacific Northwest our winter usually ends after about February 25-28. In March our chances of an arctic outbreak or any lowland snow dramatically decrease, however mountain snow and wind events are still possible. You might be thinking so what, its only the 2nd week of February.

Here is why I think our lowland winter is over.

Currently we have a big ridge of high pressure sitting just to the west of us causing the storm track (jet stream) to go over us and giving us mild temps.

Now here is an image of the 18z GFS ensemble mean 500mb heights at hour 288 (2/23/12)

Notice the ridge of high pressure is still sitting there almost 2 weeks from now.

However there is only one last chance of winter that models are hinting at.

The image below is the 18z GFS ensemble mean 500mb heights at hour 324 (2/25/12)

Notice how the ridge moves to the northwest allowing the cold air to seep in.

Now if this does not happen then our winter is over for the lowlands.

My forecast:

Timberline Forecast via NWS:

Sunday: Increasing clouds, with a high near 32. West wind between 5 and 8 mph.

Sunday Night: Snow likely. Cloudy, with a low around 23. West southwest wind between 5 and 8 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 3 inches possible.

Monday: Snow showers likely, mainly before 4pm. Cloudy, with a high near 24. Northwest wind around 8 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 3 inches possible.

Monday Night: A 30 percent chance of snow showers, mainly before 10pm. Cloudy, with a low around 22. North northwest wind between 6 and 8 mph. Little or no snow accumulation expected.

Tuesday: A 30 percent chance of snow, mainly after 10am. Mostly cloudy, with a high near 26. Little or no snow accumulation expected.

Tuesday Night: A 40 percent chance of snow showers. Mostly cloudy, with a low around 21. Little or no snow accumulation expected.

Wednesday: A chance of snow showers. Partly sunny, with a high near 28.

Wednesday Night: A slight chance of snow showers. Mostly cloudy, with a low around 27.

Thanks for reading

-Michael

Micro-climates and a Small Pattern Change

2012-02-06T18:46:00.000-08:00

This weekend was just gorgeous! Some locations have even received their first 60 degree day on Sunday.

Now what has been causing this beautiful weather? This is being caused by a big upper level high sitting just to the east of us driving all the weather systems around us.

The image below shows the upper level high making the storm track bend around and over our region.

I'm pretty sure all of you have felt that east wind out there. The east wind is being caused by low level high being bottled up against the cascades in the Hood River Valley. Winds gusted at crown point up to 77 mph on Friday and are still gusting up to 70 mph today(Monday). However Pressure gradients are still slowly climbing creating some very strong wind ( gusts 50-60) near the gorge.
Micro-climates:

Now this east wind is causing micro-climates, and a very noticeable one is in the Battle Ground/Hockinson area.

To show you this micro-climate, this image shows the temperatures at 12:00 am Monday.

Notice how the temps outside the red circle are considerably warmer by about 17 degrees in places.

Now What causes this Micro-climate? This is caused my Larch Mt. and Silver Star Mt. Blocking the east wind. You can really well see how the wind is blocked on this WRF-GFS run

Pattern change:

Models are now mostly agreeing on a small pattern change starting tomorrow night due to the upper level high deteriorating. now this pattern change will be more wet than it has been but not a complete washout.

My forecast:

Timberline Forecast:

Tuesday: Partly sunny, with a high near 34. South southeast wind between 13 and 17 mph, with gusts as high as 29 mph.

Tuesday Night: A 20 percent chance of snow after 10pm. Mostly cloudy, with a low around 23. South wind 8 to 10 mph becoming west.

Wednesday: A 20 percent chance of snow. Partly sunny, with a high near 35. West wind between 8 and 10 mph.

Wednesday Night: Partly cloudy, with a low around 26. West wind between 3 and 10 mph.

Thursday: Mostly sunny, with a high near 41.

Thursday Night: Mostly cloudy, with a low around 25.

Friday: A slight chance of snow. Mostly cloudy, with a high near 38.

Friday Night: A chance of snow. Mostly cloudy, with a low around 25.
Saturday: A chance of snow showers. Mostly cloudy, with a high near 34.

Thanks for reading

-Michael

A Very Dry Start To February.

2012-01-31T21:18:00.000-08:00

This February will start out very dry and mild as a big ridge of high pressure will build over us.

the Images below are the CPC 6-10 day outlooks for temperature and precipitation.

Notice how the whole western U.S. is above average in temperature and below average in precip.

This dry weather will be caused by a big upper level ridge developing over us on Wednesday and sending the jet stream way to our north.

The image below is the 00z GFS-WRF showing the upper level high on Thursday.(indicated by the "H")

This setup will also create quite strong east winds especially near the gorge.

Now the reason for the east wind will be low level high pressure will bottle up against the cascades in the Columbia River valley, and will cause the pressure gradient to be around 7-8mb between PDX and DLS which would give the gorge good winds, but in addition to that a shallow layer of cold air will be present and the big difference in temperature should increase the winds even more.

In the image below the 00Z GFS-WRF shows the high pressure bottled up behind the cascades on Friday.

If you really like strong wind head up to Crown Point on Friday or Saturday, winds will be gusting around 80-100 mph there!

My forecast:

Timberline forecast:

Wednesday: Snow showers, mainly before 10am. High near 32. West wind around 21 mph, with gusts as high as 33 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 2 inches possible.

Wednesday Night: A 20 percent chance of snow showers before 10pm. Mostly cloudy, with a low around 24. Northwest wind between 5 and 9 mph.

Thursday: Mostly sunny, with a high near 35. East southeast wind between 5 and 8 mph.

Thursday Night: Partly cloudy, with a low around 24. South wind between 9 and 11 mph.

Friday: Mostly sunny, with a high near 36.

Friday Night: Partly cloudy, with a low around 25.

Saturday: Mostly sunny, with a high near 37.

Saturday Night: Partly cloudy, with a low around 24.

Sunday: Mostly sunny, with a high near 34.

Sunday Night: Mostly cloudy, with a low around 24.

Thanks for reading

-Michael

Back to Slow Weather

2012-01-27T20:13:00.000-08:00

After this wild middle of January we are now heading into much slower weather pattern . Now what do I mean by "slower"? Well I mean long period of morning fog turning to afternoon sun with occasional shots of rain.

Now what will be causing this?

This will be caused by an upper level high developing on Thursday over the central U.S. causing the storm track to go to the north and keeping us dry.

The image below shows the upper level high driving the jet stream to the north.

Now look what happens the Monday after that

The high develops even stronger over our area pushing the storm track way into Canada.

Once we get past the middle of February our chances of an arctic outbreak will keep getting smaller, so it is possible but unlikely that we will get an arctic outbreak this winter.

My forecast:

Timberline Forecast:

Saturday: Partly sunny, with a high near 39. West northwest wind between 13 and 15 mph, with gusts as high as 22 mph.

Saturday Night: Mostly cloudy, with a low around 26. Breezy, with a west southwest wind between 20 and 23 mph, with gusts as high as 34 mph.

Sunday: Snow. High near 35. Windy, with a west southwest wind around 30 mph, with gusts as high as 46 mph. Chance of precipitation is 90%. New snow accumulation of 3 to 7 inches possible.

Sunday Night: Snow showers. Low around 24. Breezy, with a west wind between 26 and 29 mph, with gusts as high as 44 mph. Chance of precipitation is 90%. New snow accumulation of 8 to 12 inches possible.

Monday: Snow showers likely. Mostly cloudy and breezy, with a high near 32. Chance of precipitation is 70%. New snow accumulation of 3 to 5 inches possible.

Monday Night: Snow likely. Cloudy, with a low around 25. Chance of precipitation is 70%. New snow accumulation of 1 to 2 inches possible.

Tuesday: Snow likely. Cloudy, with a high near 33.

Tuesday Night: Snow likely. Cloudy, with a low around 25.

Thanks for reading

-Michael

Last Round of Rain Then Dry.

2012-01-23T17:19:00.000-08:00

I haven't posted in a while due to a busy schedule...anyways lets recap last week.

PDX officially received 2.2 inches of snow from the system on Tuesday night, on Friday lots of flooding happened in the Salem area due to 5-6 inches of rain in 3 days.

Also the ski resorts had lots of new snow, the image below shows 1 week snowfall totals as of 1/22/12

Now tomorrow a warm front will bring a large amount of moisture to our area (image below)

Rainfall totals will be around 1-2 inches in the valley and 4-5 inches in the coast range

After this system clears out of here on Thursday night a ridge of high pressure will develop and push the jet stream up to our north, which makes the storms from the pacific ride over the high pressure. (image below)

Now due to the high pressure we will most likely get an inversion due to the lack of mixing, which will create fog.

My forecast:

Timberline Forecast:

Tuesday: Snow before 4pm, then rain and snow. The snow could be heavy at times. High near 32. Windy, with a south southwest wind around 32 mph, with gusts as high as 50 mph. Chance of precipitation is 100%. New snow accumulation of 9 to 13 inches possible.

Tuesday Night: Rain. Snow level 7000 feet. Steady temperature around 31. Windy, with a west wind between 38 and 44 mph, with gusts as high as 70 mph. Chance of precipitation is 100%. New precipitation amounts between three quarters and one inch possible.

Wednesday: Snow. High near 34. Windy, with a west wind around 31 mph, with gusts as high as 50 mph. Chance of precipitation is 90%. New snow accumulation of 3 to 7 inches possible.

Wednesday Night: Snow. Low around 27. Southwest wind between 18 and 21 mph, with gusts as high as 31 mph. Chance of precipitation is 100%. New snow accumulation of 7 to 11 inches possible.

Thursday: Snow. High near 32. Breezy. Chance of precipitation is 80%. New snow accumulation of 3 to 5 inches possible.

Thursday Night: A 20 percent chance of snow showers. Mostly cloudy, with a low around 23.

Friday: Mostly sunny, with a high near 33.

Friday Night: Partly cloudy, with a low around 25.

Thanks for reading

-Michael

Snow Totals.

2012-01-18T15:13:00.000-08:00

Here are snowfall totals from today's storm (in inches)

Washington:

Toutle: 18"
LaCenter: 13"
Yacolt: 12"
Longveiw: 9"
Carson: 7.5"
Stevenson: 6"
Camas: 4.75"
Battle Ground: 4.5"
Vancouver 3"

Oregon:

Parkdale: 13"
Rainier : 12"
Forest Grove: 11"
Scappoose: 10"
Hood River: 8"
Happy Valley: 4"
Portland: 2"

Now what was the reason for the snow switching over to rain?

Here let me explain with this image

While we were in the cold air the low pressure came and gave us moisture. Now early this morning a warm front came and brought us warm air and it changed over to rain.

Here are a few images of today's snowfall

Dufur, Oregon

Vernonia, Oregon, taken by Garrey Kinney

Forest Grove, Oregon, taken by Erik Lentz

Cascade Locks, Oregon, Taken by Serge Tishchenko

My Forecast:

Timberline Forecast:

Tonight: Snow. The snow could be heavy at times. Temperature rising to around 29 by 4am. Windy, with a west southwest wind between 29 and 34 mph, with gusts as high as 45 mph. Chance of precipitation is 90%. New snow accumulation of 12 to 18 inches possible.

Thursday: Snow. The snow could be heavy at times. High near 32. West southwest wind around 15 mph. Chance of precipitation is 100%. New snow accumulation of 20 to 26 inches possible.

Thursday Night: Snow. The snow could be heavy at times. Low around 24. West wind between 9 and 16 mph, with gusts as high as 20 mph. Chance of precipitation is 90%. New snow accumulation of 5 to 9 inches possible.

Friday: Snow. High near 30. Southwest wind between 15 and 21 mph, with gusts as high as 24 mph. Chance of precipitation is 90%. New snow accumulation of 4 to 8 inches possible.

Friday Night: Snow. The snow could be heavy at times. Low around 23. Breezy. Chance of precipitation is 100%. New snow accumulation of 10 to 14 inches possible.

Saturday: Snow. High near 29. Breezy. Chance of precipitation is 90%. New snow accumulation of 5 to 9 inches possible.

Thanks for reading

-Michael

Tonight's Snow Event.

2012-01-17T14:48:00.000-08:00

We are currently under a winter storm watch and it will be updated to a winter storm warning soon.

My thoughts on tonight's snow:

Now-8pm: rain/snow showers, snow above 500ft, turning to all snow
8pm-4am: snow, heavy at times
4am - 10 am: a warm front will come through and depending on the placement of the low the timing of the switch to rain will vary by location.

Accumulation:

South of PDX: 0 to 1 inch switch to rain at 2-3 am.
PDX: 1-3 inches switch to rain at 4 -5 am.
Clark County: 3-5 inches: switch to rain at 6-7 am.

Now why is the timing of the switch to rain so difficult? It is difficult because it all depend on the track of a low pressure system, If the system tracks to the north of Portland we would get strong south wind and switch to rain around 3 am . If the system goes over PDX then we would switch to rain around 6am,

Here is the 24 hour snowfall total ending at Wednesday 4pm

Wild Week With More Snow and a Possible Windstorm.

2012-01-15T15:12:00.000-08:00

Today morning many of you woke up with a dusting of snow. The official Portland snowfall total is 0.5 inches.

Now will it Snow again?

Some showers today will produce snow

The best chance for sticking snow once again will be tomorrow starting around 7pm.

On Tuesday the forecast is difficult, the GFS model suggests we warm up quickly, the euro model suggests that we warm up slowly in the afternoon, But the NAM model says that the 850mb temp will be around -7 to -8c (borderline for snow) all day. All of the models say there will be moisture available on Tuesday,

Now on Wednesday the chance of snow will depend on the placement of the low, too far north and we get rain.

The image below shows the GFS placing the low (red) to the north of Astoria, however for us to get snow the low must be in the blue zone.

End of the week:

all models are hinting at a very deep low coming in some time Thursday-Saturday. Now what does a deep low do? A deep low gives us a big pressure gradient witch gives us strong wind.

the image below is the 18z GFS on Friday

The pressure gradient from Eugene to Olympia is about 14mb witch would give us wind gusts of 45-50 mph

My forecast:

Timberline Forecast:

Tonight: Snow showers. Low around 9. Wind chill values as low as -10. West northwest wind around 18 mph, with gusts as high as 26 mph. Chance of precipitation is 80%. New snow accumulation of 2 to 4 inches possible.

M.L.King Day: Snow showers. High near 14. Wind chill values as low as -10. Windy, with a west wind 21 to 24 mph increasing to between 29 and 32 mph. Winds could gust as high as 45 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 5 inches possible.

Monday Night: Snow showers. Low around 12. Wind chill values as low as -10. Windy, with a west wind between 28 and 33 mph, with gusts as high as 47 mph. Chance of precipitation is 100%. New snow accumulation of 7 to 11 inches possible.

Tuesday: Snow showers. High near 20. Windy, with a west wind between 28 and 30 mph, with gusts as high as 41 mph. Chance of precipitation is 100%. New snow accumulation of 10 to 14 inches possible.

Tuesday Night: Snow. Low around 14. Windy. Chance of precipitation is 100%. New snow accumulation of 11 to 17 inches possible.

Wednesday: Snow. The snow could be heavy at times. High near 30. Windy. Chance of precipitation is 100%. New snow accumulation of 15 to 21 inches possible.

Thanks for reading

-Michael

Quick update on Snow.

2012-01-14T23:21:00.000-08:00

Quick late night post, will post more tomorrow
As many of you have seen we are getting snow showers mixing down into the lowest elevations.

Now some media has really hyped this event saying "Winter Storm" yet there live crews were standing in partly cloudy conditions.
So how much and where will it snow?

Trace to 2 inches is possible anywhere from tonight through Monday evening.
The only problem is that the shower are limited. The good news is that the HRRR model (below) is showing some snow being able to accumulate tonight.

In other words don't be surprised if you don't have snow but across town someone is saying they have over an inch of snow.
My forecast:

Outlook on Snow.

2012-01-11T16:43:00.001-08:00

As many of you have heard this weekend we might end up having snow, here are my thoughts on this...

First off very often when we have chances of snow we end up being too dry for snow this time however this time there will be plenty of moisture but not much cold air. Let me explain, for snow down here at the valley floor we need the 850mb (5,000ft) temp to be -8c or lower, so lets take a look at what the models say.

All the models agree on the 850mb temp on being -7 to -9c (very borderline for snow).

Now here's the problem, during this period there will be a slight south to north pressure gradient giving us a light southwest wind. Now whats the problem with southwest wind? The problem is the southwest wind is a warm wind and has killed many snow chances in the past.and this time they will probably give us rain/snow mix or very wet snow.

Where and how much will it snow?

Sunday-Monday

Lets go by elevation.(keep in mind this could change)

1500ft+:6-12 inches

500-1500:1-4 inches

Valley floor: trace-1 inch

Now there is great news for ski resorts that are suffering from lack of snow.

The image below is a forecast of 24 hour snowfall ending on Wednesday afternoon.

Over 30 inches (3 feet of snow!) in the cascades! that will put ski resorts back into business.

My forecast:

Timberline Forecast:

Thursday: Sunny, with a high near 32. Wind chill values as low as -16. East southeast wind around 14 mph.

Thursday Night: Mostly clear, with a low around 7. Wind chill values as low as -4. South southeast wind between 6 and 10 mph.

Friday: Sunny, with a high near 38. Calm wind.

Friday Night: Partly cloudy, with a low around 10. South southwest wind around 6 mph.

Saturday: Rain showers likely, mainly after 4pm. Snow level 6300 feet lowering to 5200 feet. Partly sunny, with a high near 40. Chance of precipitation is 60%.

Saturday Night: Rain and snow showers likely, becoming all snow after 10pm. Cloudy, with a low around 12. Chance of precipitation is 70%. Little or no snow accumulation expected.

Sunday: Snow showers. Mostly cloudy, with a high near 12.

Sunday Night: Snow showers likely. Cloudy, with a low around 2.

M.L.King Day: Snow showers. Cloudy, with a high near 17.

Monday Night: Snow showers likely. Cloudy, with a low around 4.

Thanks for reading

-Michael

Very Inconsistent Models and Berried in Snow

2012-01-09T18:20:00.000-08:00

Before I get to the inconsistent models I want to talk about were the snow has been.

So far this winter the whole nation has had very little snow. Well now it appears now that we have found where it has been...

The answer is...Alaska! yep Alaska just look at these photos by a member of the pacific northwest weather group in Cordova Alaska.

The town is literally Berried! Cordova's average yearly snowfall is 127 inches but so far this year over 216 inches (18 feet) has fallen and it has not stopped snowing for over 24 days in a row! The town has declared a state of emergency and the Alaskan coast guard is helping them clear the snow.

Here is another image of a ski lift on Mt. Eyak near the town.

Yes that little thing poking out is the chair lift!

and just one more photo to show how much snow there is

Now back to our weather...

Long term:

Models are still being very in consistent starting around Sunday night, however the European model (witch is one of the more reliable models) is showing a trend to colder weather.

The image below shows the 12z euro ensembles(separate models that support)

Note: for snow the 850 mb temp must be -8c or lower.

In the image notice how many of the ensembles take the 850 mb temp down to -8--10c. Meanwhile the GFS has 850mb temps at 0-5c at the same time.

My Forecast:

Timberline Forecast:

Tuesday: Mostly cloudy, then gradually becoming sunny, with a high near 30. Northwest wind between 3 and 11 mph.

Tuesday Night: Mostly clear, with a low around 24. East wind between 6 and 11 mph.

Wednesday: Sunny, with a high near 33. East wind between 3 and 10 mph.

Wednesday Night: Partly cloudy, with a low around 22. Light southeast wind.

Thursday: Mostly sunny, with a high near 34.

Thursday Night: Partly cloudy, with a low around 24.

Friday: Partly sunny, with a high near 34.

Friday Night: Mostly cloudy, with a low around 25.

Saturday: A slight chance of snow. Mostly cloudy, with a high near 34.

Thanks for reading

-Michael

Interesting Model Runs and a Dry Weekend .

2012-01-06T16:52:00.000-08:00

I have not posted for awhile now due to a vacation I took, anyways moving on...
Before I talk about the short term I want the talk about the long term.

Models runs in the long range are being very inconsistent however there is a trend toward more cool weather

let me show you what I mean by inconsistent...

This image is of the last 4 GFS model runs, now pay attention to the 850mb (5,000ft) circled in red.

Notice how the 12z got rid of the arctic air then the next run brings it back.

Now for us to get snow the 850 mb temp has to be -8c or lower.

Also the ensembles (separate model runs) are not totally agreeing with the model

Here is a look at the ensembles.

Notice how the operational run is one of the runs that stick out .

bottom line is that the arctic air is still up for debate .

Short term:

After today's system a ridge of high pressure will develop and give us dry weather for the weekend. Then on Monday a shortwave will come through giving us rain. Then on Tuesday a big ridge of high pressure will build over our area (indicated in red in the image below) giving us dry weather till next Saturday.

Forecast: I'm trying a new graphic

Timberline Forecast:

Tonight: Snow. Low around 25. West wind around 15 mph becoming south. Winds could gust as high as 20 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 2 inches possible.

Saturday: Partly sunny, with a high near 32. West northwest wind around 8 mph.

Saturday Night: Partly cloudy, with a low around 27. West northwest wind between 6 and 8 mph.

Sunday: Sunny, with a high near 38. West wind around 7 mph.

Sunday Night: Partly cloudy, with a low around 27.

Monday: A slight chance of rain. Snow level 6900 feet. Mostly cloudy, with a high near 40. Chance of precipitation is 20%.

Monday Night: Snow likely. Mostly cloudy, with a low around 28.

Tuesday: Mostly sunny, with a high near 36.

Thanks for reading

-Michael

Rain Totals and Low Snow Levels.

2011-12-28T17:26:00.000-08:00

The past 24 hours have been very wet. just look at the 24 hour rainfall totals.

The image below shows the 24 hour rainfall totals ending at 4:30pm in the east metro area.

6.56 inches at Log Creek!

Here are the 24 hour rainfall totals ending at 4:30pm in the west metro area.

5.24 inches of rain at Lees Camp!

All this precipitation has been rain in the mountains below 7.000 feet which is really bad for ski resorts
just look at this photo of a big puddle at Hoodo Ski Resort

however on Friday afternoon a cold front will come through and lower the snow lever below pass levels and dump close to a foot of new snow in the mountains.
That same cold front will drop snow levels down to about 1,500 feet on Friday afternoon giving us in the valley, hail or ice pellets in heavy showers.
Some other good news is that New Years is looking dry due to a ridge of high pressure building over our area.
The image below shows the ridge of high pressure(indicated in blue) over us on New Years day

Forecast:
Thursday: Dry in the morning, steady afternoon rain.high temp:52
Friday: Morning rain, afternoon showers mixed with hail or ice pellets. high temp 53 lowering to 42
Saturday: Morning showers then dry. high temp: 48
Timberline forecast:
Thursday: Snow. High near 37. Breezy, with a west wind between 25 and 29 mph, with gusts as high as 34 mph. Chance of precipitation is 90%. New snow accumulation of 3 to 7 inches possible.

Thursday Night: Rain and snow. Snow level rising to 7100 feet. Temperature rising to around 35 by 1am. Windy, with a west southwest wind between 23 and 32 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New snow accumulation of 7 to 11 inches possible.

Friday: Rain and snow showers, becoming all snow after 10am. High near 36. Windy, with a west wind between 28 and 32 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New snow accumulation of 5 to 9 inches possible.

Friday Night: Snow showers. Low around 26. Windy, with a west wind between 28 and 32 mph, with gusts as high as 38 mph. Chance of precipitation is 80%. New snow accumulation of 2 to 4 inches possible.

Saturday: A 50 percent chance of snow showers. Mostly cloudy, with a high near 33. Little or no snow accumulation expected.

Saturday Night: A 20 percent chance of snow showers. Mostly cloudy, with a low around 28.

Thanks for reading

-Michael

Wet Week and Possibility for Wind.

2011-12-26T21:32:00.000-08:00

The pattern has now officially changed to wet. This week is going to be very wet. How wet?

Well models (like the one below) are showing rainfall totals over 1.50 inches of rain in the valley.

This model run (the 00z WRF-GFS) shows rain fall totals in the valley over 1.5 inches and over 5 inches in the cascades/coast range!

Now whats causing all this rain?

The reason is a strong jet stream is aimed strait at us bringing in weather systems every 1-2 days.

The image below shows the forecast for the jet stream winds.

Notice how the strong winds are aimed directly at us.

So what, strong winds, how does that give us rain?

Here is a view of the water vapor satellite imagery (this shows the water vapor or moisture in the atmosphere)

Notice how a large amount of moisture (circled in red) is aimed for us (circled in yellow)

The strong jet stream winds drive the moisture at us and give us rain.

The Forecast:

Tuesday: light rain, getting heavier in the evening

Wednesday: steady afternoon rain

Thursday: steady rain dying down in the evening.

Friday: rain again!

Now what about the winds?

Tomorrow will be quiet breezy in the evening due to pressure gradient of about 5-6 millibars between PDX and Eugene.

However on Thursday/Friday models are being inconsistent in a low pressure system so it is very uncertain on the winds.

Timberline Forecast:

Tuesday: Snow. High near 36. Windy, with a west wind between 29 and 31 mph, with gusts as high as 38 mph. Chance of precipitation is 90%. New snow accumulation of 3 to 5 inches possible.

Tuesday Night: Snow before 10pm, then rain. Snow level rising to 8400 feet. Low around 32. Windy, with a west southwest wind 30 to 33 mph increasing to between 41 and 44 mph. Winds could gust as high as 55 mph. Chance of precipitation is 100%. New snow accumulation of 1 to 3 inches possible.

Wednesday: Rain. High near 42. Windy, with a west southwest wind between 32 and 37 mph, with gusts as high as 49 mph. Chance of precipitation is 90%. New rainfall amounts between three quarters and one inch possible.

Wednesday Night: Rain before 10pm, then snow. Snow level 7500 feet lowering to 6300 feet. Low around 32. Windy, with a west southwest wind between 37 and 39 mph, with gusts as high as 50 mph. Chance of precipitation is 100%. New snow accumulation of 1 to 2 inches possible.

Thursday: Snow. High near 39. Windy. Chance of precipitation is 90%. New snow accumulation of 2 to 4 inches possible.

Thursday Night: Snow likely. Cloudy and windy, with a low around 31. Chance of precipitation is 70%. Little or no snow accumulation expected

Thanks for reading

-Michael

Christmas Gift of a Pattern Change.

2011-12-21T16:55:00.000-08:00

Finally a pattern change and i'm not advertising this like Obama does.

So far this December has had a big ridge of high pressure sitting on top of us giving us dry and foggy weather

the image below shows the jet stream winds and I have indicated the ridge of high pressure in red

How does this give us dry weather? This gives us dry weather by making all the moisture ride the jet stream over and around the high. Now this week starting Christmas day that high pressure will move east and allow the jet stream to aim at us

The image above shows the forecast for the jet stream winds on Tuesday, notice how the strong winds (yellow color) are aimed strait at us.

Christmas Forecast:

Christmas eve: A weak warm front will move to the north of us giving us a few showers but we should stay mostly dry.

Christmas day: A cold front following the warm front will come through giving us rain followed by showers.

Following Christmas the week looks pretty wet.

I probably wont be posting till after Christmas so....

Timberline Forecast:

Thursday: Mostly sunny, with a high near 35. South southeast wind between 15 and 17 mph, with gusts as high as 25 mph.

Thursday Night: Mostly cloudy, with a low around 23. South southwest wind between 14 and 17 mph, with gusts as high as 23 mph.

Friday: A 50 percent chance of snow, mainly before 4pm. Mostly cloudy, with a high near 34. Breezy, with a west wind between 21 and 23 mph, with gusts as high as 32 mph. New snow accumulation of less than a half inch possible.

Friday Night: A 20 percent chance of snow before 10pm. Mostly cloudy, with a low around 25. West wind around 13 mph.

Saturday: Mostly sunny, with a high near 35.

Saturday Night: Mostly cloudy, with a low around 27.

Christmas Day: A chance of snow. Mostly cloudy, with a high near 33.

Sunday Night: A chance of snow. Mostly cloudy, with a low around 27.

Monday: A chance of snow. Mostly cloudy, with a high near 34.

Monday Night: A chance of snow. Mostly cloudy, with a low around 26.

Thanks for reading

-Michael