Part I - January 2020 Weather Discussion for the PNW

[Frontal Snowsquall]

Current Rod Hill forecast for PDX.

 

Tue: 36/32

Wed: 30/26

Thu: 30/26

Fri: 32/27

 

Monday Night: Likely showers, moisture becomes mostly snow with morning accumulations of 1-3" possible in scattered locations.

 

Tuesday: Possible snow accumulation early morning, snow showers likely during the day. Look for a grassy dusting to 3 inches of total snow.

 

Tuesday Night: Gusty east winds develop, snow flurries overnight.

 

Wednesday: Morning flurries, then increasing snow mid to late afternoon. Cold wind chills with gusty east winds to 45 mph near the Gorge.

 

Wednesday Night: Increasing snow with possible accumulations of 6" by morning. This is a forecast possibility - watch for updates.

 

Thursday: Snow or an icy mix. Forecast is still uncertain, as to south verses east winds and a wintry mix or all snow. Possible 6" total snowfall.

 

Thursday Night: Snow or wintry mix of showers.

 

Friday: Snow showers or a wintry mix.

 

http://portlandweather.com/areas/portland-7-day

[MR.SNOWMIZER]

Beautiful day..

[MR.SNOWMIZER]

The system is further south by a couple hundred miles according the the 18z gfs. It looks to be hauling a**.

[Prairiedog]

Current Rod Hill forecast for PDX.

 

Tue: 36/32

Wed: 30/26

Thu: 30/26

Fri: 32/27

 

Monday Night: Likely showers, moisture becomes mostly snow with morning accumulations of 1-3" possible in scattered locations.

 

Tuesday: Possible snow accumulation early morning, snow showers likely during the day. Look for a grassy dusting to 3 inches of total snow.

 

Tuesday Night: Gusty east winds develop, snow flurries overnight.

 

Wednesday: Morning flurries, then increasing snow mid to late afternoon. Cold wind chills with gusty east winds to 45 mph near the Gorge.

 

Wednesday Night: Increasing snow with possible accumulations of 6" by morning. This is a forecast possibility - watch for updates.

 

Thursday: Snow or an icy mix. Forecast is still uncertain, as to south verses east winds and a wintry mix or all snow. Possible 6" total snowfall.

 

Thursday Night: Snow or wintry mix of showers.

 

Friday: Snow showers or a wintry mix.

 

http://portlandweather.com/areas/portland-7-day

Not sure he generated that.  He had PDX up to 40f on Friday yesterday. 

[MikeInEverett]

Gonna be optimistic and expect 3-5” tomorrow evening here. Hope that low stays on its current track so the location of the CZ stays the same.

[Requiem]

The system is further south by a couple hundred miles according the the 18z gfs. It looks to be hauling a**.

 

In terms of actual surface analysis compared to the GFS?

[MR.SNOWMIZER]

In terms of actual surface analysis compared to the GFS?

Yes compare 18z gfs to sat pic

[TT-SEA]

Looking forward to a tasteful 3” - 6” of snow by Monday and a Seahawks win tomorrow (not sure which is more wishful thinking)

I am not feeling it for us now. ECMWF shows tomorrow evening is about the same as this evening. Pretty strong SW wind south of the c-zone. Our house has been shaking in the wind the last couple hours and it's totally dry now.

[TT-SEA]

Gonna be optimistic and expect 3-5” tomorrow evening here. Hope that low stays on its current track so the location of the CZ stays the same.

You might be in the best spot of all of us. Even better than Randy tomorrow evening.

[bainbridgekid]

Gonna be optimistic and expect 3-5” tomorrow evening here. Hope that low stays on its current track so the location of the CZ stays the same.

I like your chances there.

[Requiem]

Yes compare 18z gfs to sat pic

 

Hmm... hopefully that bodes well. I'm expecting 2-4 inches by the end of the week-- optimistically.

[seattleweatherguy]

nws going for this in bothell not sure if that will pan out. id be happy with an inch personally

 

Rain before 4pm, then rain and snow. The snow could be heavy at times. High near 39. West southwest wind 7 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 100%. New snow accumulation of 1 to 2 inches possible.

Sunday Night

Snow, mainly before 10pm. The snow could be heavy at times. Low around 28. Wind chill values between 16 and 26. Northwest wind 13 to 16 mph, with gusts as high as 21 mph. Chance of precipitation is 90%. New snow accumulation of 2 to 4 inches possible.

[jcmcgaffey]

A winter weather advisory would have made more sense

at this point the mets can start to see the setup to everything happening so they can prob get an idea of any rough changes. They can probably even extrapolate a bit like if the ridge is forming further west than models and can get an idea of what that will mean. They are probably doing that to figure we might get more snow than the models are currently showing.

[snow_wizard]

Beautiful day..

 

That almost look like really thick frost on the trees.  Gorgeous!

[MR.SNOWMIZER]

I like your chances there.

Thinking back at these situations in the past there have been many that had forecasted couple inches and places ended up getting 10. I would be surprised if my place gets anything with this first round but I will score the rest of the week for sure. I would expect mossman to get around 8 inches no problem. The sw wind heading up the sound is what's going to fuel this thing and if some cold air can get mixed in there in time it could be a good show.

[TT-SEA]

Thinking back at these situations in the past there have been many that had forecasted couple inches and places ended up getting 10. I would be surprised if my place gets anything with this first round but I will score the rest of the week for sure. I would expect mossman to get around 8 inches no problem. The sw wind heading up the sound is what's going to fuel this thing and if some cold air can get mixed in there in time it could be a good show.

You are in the sweet spot from Wednesday-Friday.

[snow_wizard]

The 18z GFS graph has a much nicer look to it.   A long sustained run of sub -5 850s over Seattle and a nice dip after the mid week snow that is looking better.

[runninthruda206]

The system is further south by a couple hundred miles according the the 18z gfs. It looks to be hauling a**.

 

 

Really?! Interesting!

[bainbridgekid]

Thinking back at these situations in the past there have been many that had forecasted couple inches and places ended up getting 10. I would be surprised if my place gets anything with this first round but I will score the rest of the week for sure. I would expect mossman to get around 8 inches no problem. The sw wind heading up the sound is what's going to fuel this thing and if some cold air can get mixed in there in time it could be a good show.

That thought has crossed my mind as well. 

 

The area the CZ hits the hardest almost always gets significantly more than any forecast.

[Perturbed Member]

Hmm... hopefully that bodes well. I'm expecting 2-4 inches by the end of the week-- optimistically.

 

 

You will do well, your elevation should be enough to get something Monday.

[MR.SNOWMIZER]

That almost look like really thick frost on the trees.  Gorgeous!

One thing I have figured out about this area is certain elevations and how much its effects the weather here. That place is 5000ft and pretty much from mid November to mid march it never goes above freezing. You are right that is heavy frost and snow as it's always socked in the clouds. 4000ft and up in this area the trees look like that almost all winter.

[TT-SEA]

Just keeping it real here... satellite images can be misleading. Every single model has the same track of the low tomorrow now. It's going to follow that general track. Cold air has been a little slower to come down as well in all the models... including on the 18z ECMWF. So the models have a good handle on that as well.

[MR.SNOWMIZER]

You are in the sweet spot from Wednesday-Friday.

I know you want to watch the game but if that zone gets pushed se into the cascades you will get hammered like in the past. Maybe even with the sw wind because this storm has a pretty cold tap of air wrapping around it's core.

[Frontal Snowsquall]

Great. Split flow is forecast to come back after this is over. Looks like it’s back to hardpack and ice skiing while watching California get slammed.

 

Who’s ready for yet another warmer than average spring?

[TT-SEA]

I know you want to watch the game but if that zone gets pushed se into the cascades you will get hammered like in the past. Maybe even with the sw wind because this storm has a pretty cold tap of air wrapping around it's core.

ECMWF would show something for here at this point.

[snow_wizard]

That thought has crossed my mind as well. 

 

The area the CZ hits the hardest almost always gets significantly more than any forecast.

 

The zone will slide south as the Arctic air works its way down as well.  That should fill in places further south.

[MikeInEverett]

Just keeping it real here... satellite images can be misleading. Every single model has the same track of the low tomorrow now. It's going to follow that general track. Cold air has been a little slower to come down as well in all the models... including on the 18z ECMWF. So the models have a good handle o that as well.

Yeah, I’ve noticed over the years before these events images of the satellites are always posted and people like to say that it’s completely different than what the models show, and it ends up going as the models show basically every time.

[Poulsbo Snowman]

Anyone having fun?  I am.  Should be good for a couple to a few inches tomorrow night, followed by 2 days of cold--followed by more snow.   Not bad.  Love watching the model riding.   

[snow_wizard]

One thing I have figured out about this area is certain elevations and how much its effects the weather here. That place is 5000ft and pretty much from mid November to mid march it never goes above freezing. You are right that is heavy frost and snow as it's always socked in the clouds. 4000ft and up in this area the trees look like that almost all winter.

 

Wow!  Some amazing climates in this state.  Some places really have big time winters.

[MR.SNOWMIZER]

Just keeping it real here... satellite images can be misleading. Every single model has the same track of the low tomorrow now. It's going to follow that general track. Cold air has been a little slower to come down as well in all the models... including on the 18z ECMWF. So the models have a good handle on that as well.

Make sure I'm looking at this right but the center of the low on the 18z at 4pm looks further up the coast than what sat pic shows. Just an observation. It sure looks to be moving really fast. And yeah we are to close for a sudden south trend.

[snow_wizard]

I'm glad everyone is feeling good again.  

[TT-SEA]

The zone will slide south as the Arctic air works its way down as well. That should fill in places further south.

There is no arctic air over Seattle even on Tuesday.

[MR.SNOWMIZER]

There is no arctic air over Seattle even on Tuesday.

according to the euro or gfs or both?

[TT-SEA]

according to the euro or gfs or both?

ECMWF for sure. Shows a high of 34 with a SW wind. It's not arctic. You can call it that... but it's not. And the 18Z ECMWF trended a little warmer.

[MR.SNOWMIZER]

Ok so every professional met in the northwest agrees there will be arctic air over the area Tuesday But according to this forum there is not?

[MR.SNOWMIZER]

ECMWF for sure. Shows a high of 34 with a SW wind. It's not arctic. You can call it that... but it's not. And the 18Z ECMWF trended a little warmer.

Let's get scientific here. What does all the other world models show for highs then let's make a blanket statement with ALL the information not just from 1 preferred model.

[The Swamp]

ECMWF for sure. Shows a high of 34 with a SW wind. It's not arctic. You can call it that... but it's not. And the 18Z ECMWF trended a little warmer.

what daytime temperature would you call arctic?

[TT-SEA]

Let's get scientific here. What does all the other world models show for highs then let's make a blanket statement with ALL the information not just from 1 preferred model.

I said all the models showed the same track of the low. Even the goofy NAM.

[Jesse]

Anyone having fun? I am. Should be good for a couple to a few inches tomorrow night, followed by 2 days of cold--followed by more snow. Not bad. Love watching the model riding.

We spent a few days in Poulsbo the week before Christmas. Great little town, I really liked it. A lot of cool Scandinavian heritage.

 

How does that area generally do for snow? I know some spots on the Kitsap can do quite well thanks to the topography/influence of cold air damming along the Olympics.

[TT-SEA]

what daytime temperature would you call arctic?

Ask Matt or Justin.

 

Lower than 34 with a SW wind.