December 2016 Observations and Model Discussion for the Pacific Northwest

[Gradient Keeper]

❄ Happy Holidays ❄
-Model Countdown-
Next up
*00z GFS in 3 hours 18 minutes
00z GEM in 4 hours 18 minutes
00z ECMWF in 5 hours 37 minutes

 

The pattern sets up upstream over the GOA/AK in just 72 hours
❄ Think Cold and SNOW!!!! ❄

[ShawniganLake]

Depressing eh?

It really has been the last couple of weeks. Pounding rain with the odd wet snow flake hour after hour on multiple days recently.

[Goducks09]

❄ Happy Holidays ❄

-Model Countdown-

Next up

*00z GFS in 3 hours 18 minutes

00z GEM in 4 hours 18 minutes

00z ECMWF in 5 hours 37 minutes

 

The pattern sets up upstream over the GOA/AK in just 72 hours

❄ Think Cold and SNOW!!!! ❄

 

 

It is nice to have you back these past few days, Rob!  Hopefully you stick around as things unfold over the coming days.  

[luvssnow_spokane]

Yeah the minor details will sort themselves out as we get closer to the main event. The bigger picture with the block and trough look good. Onto the 00z models!

I honestly have not seen something so good since 2008 and I am totally primed for something wonderful. It is super exciting and not to concerned about the details at this point. Just can hardly wait for it to get here! Ya!!

[MossMan]

I honestly have not seen something so good since 2008 and I am totally primed for something wonderful. It is super exciting and not to concerned about the details at this point. Just can hardly wait for it to get here! Ya!!

This is going to be the LONGEST week ever!!! Can't wait! 

[MossMan]

Some pretty nice wind gust here tonight... Anyone else windy?

Pretty calm up here so far.

 

Edit: Quite blustery now! 

[SilverFallsAndrew]

Some pretty good evaporative cooling taking place right now as my temp has dropped 6 degrees in the past hour. Radar showing echoes over me, but nothing hitting the ground. 

[luvssnow_spokane]

This is going to be the LONGEST week ever!!! Can't wait! 

Yah... it is going to be painful and I can already see it impacting my work productivity...   

[MossMan]

I see Jaya is online...what are your thoughts on the upcoming pattern?

[snow_wizard]

I honestly have not seen something so good since 2008 and I am totally primed for something wonderful. It is super exciting and not to concerned about the details at this point. Just can hardly wait for it to get here! Ya!!

We did pretty good in this area in Nov 2010, Jan 2012, and to some extent in Feb 2011.

[snow_wizard]

This has to be the first time I haven't seen evaporative cooling in a case like this. Really no outflow winds this time. South winds are going to take over quickly tonight.

[HighlandExperience]

It really has been the last couple of weeks. Pounding rain with the odd wet snow flake hour after hour on multiple days recently.

 

How much snow have you gotten since beginning of December? Seems like some areas up there really got screwed recently. 

[SilverFallsAndrew]

Horse Creek which is about 7 or 8 miles east of my place and at about 3000' is sitting at 34, but with a dp of 17, so obviously there is some evaporative cooling of the mid level airmass at play here. 

[Timmy]

Dumping snow here now.

[ShawniganLake]

How much snow have you gotten since beginning of December? Seems like some areas up there really got screwed recently.

17". Roughly 50% of our seasonal average.

[Gradient Keeper]

It is nice to have you back these past few days, Rob!  Hopefully you stick around as things unfold over the coming days.  

Thanks. I imagine I'll be extremely busy over on my FB group, but I'll definitely try to be part of the madness over here. There's nothing quite like seeing Western Weather Forum going nuts when we have an event expected or unfolding. Fun chaos.

[SilverFallsAndrew]

Dumping snow here now.

 

Nice! I didn't think it would start as anything, but rain here, but I have dropped from 40 to 33 in the past hour and a half...

[Deweydog]

New 7 Day from KPTV. #prayforsnow

 

http://lmgcorporate.com/kptv/weather/ibs_web_7-day.jpg

Apparently it will drop three degrees EXACTLY at 11:53 p.m. Sunday night.

 

#arcticfront

[Deweydog]

You may be right. Part of me almost feels like the longer we avoid a truly major blast the longer we will stay in this same general pattern.

 

There are definitely a handful of ensembles that are colder than the 18z though....

Late January.

[Jesse]

17". Roughly 50% of our seasonal average.

That's pretty good considering December isn't even over.

 

I've probably seen 1.7" here.

[Jesse]

Late January.

If we get a cold pattern like the models are advertising the first 2/3 of the month and that all leads up to a late January main course we could be looking at QUITE a chilly month.

[Deweydog]

If we get a cold pattern like the models are advertising the first 2/3 of the month and that all leads up to a late January main course we could be looking at QUITE a chilly month.

So many sexy statistical possibilities!!!

[BLI snowman]

That's pretty good considering December isn't even over.

 

I've probably seen 1.7" here.

Have had 4.5" here. Probably also about halfway to average.

[MR.SNOWMIZER]

Really starting to come down good. 32 degrees.

[MossMan]

Actually a rain/snow mix here at my work now!

[luvssnow_spokane]

I know it does not mean much, but since the wind hit temp has gone down from 43 to 39 in about 40min... I was honestly suprised to see the wind though. It shook the house. I guess I just was not expecting it.

[SilverFallsAndrew]

Just saw a report of snow falling in Battle Ground.

[SilverFallsAndrew]

Really starting to come down good. 32 degrees.

Gorgeous

[MR.SNOWMIZER]

This is going to over perform tonight here.

[HighlandExperience]

I know it does not mean much, but since the wind hit temp has gone for 43 to 39 in about 40min... I was honestly suprised to see the wind though. It shook the house. I guess I just was not expecting it.

 

Your temp has dropped to 39? or gone up to 43?

[luvssnow_spokane]

Oops gone down... to 39 heading to 38

[ShawniganLake]

Have had 4.5" here. Probably also about halfway to average.

That's what I was thinking. Pretty comparable when looking at seasonal average.

[HighlandExperience]

Oops gone down... to 39

 

Yup 38 degrees here. Heavy rain. 

[SilverFallsAndrew]

Snowing at 780' at Timber Jct west of Portland

[MR.SNOWMIZER]

Mm5 showed 8 inches for me tonight

[MR.SNOWMIZER]

Mm5 showed 8 inches for me tonight

Of snow lol.

[jaya]

I see Jaya is online...what are your thoughts on the upcoming pattern?

The details will always be up in the air a bit with this type of pattern.  But, if you like cold and snow, the models couldn't look much better (big picture).  I see on these forums that there are an incredible number of model riders (a wild ride).  You'll probably get sea-sick.  But, this looks like it has some opportunity to be an interesting period for a couple of weeks or so.  Some of our biggest years have patterns that lock in this pattern. I don't look in details at indices (AO, EPO, ...) as I am not well versed in that area.  But this upcoming pattern does have a different signature than more recent arctic outbreaks when looking at tropical forcing, block strength, etc. This upcoming pattern has the look and feel of a top 5 or 10 2 week period. Of course time will tell, and I'll be taking things a few days at a time.

 

A few things I like about the new GFS: 1) better model resolution (now about 13 km out to 240 hrs).  This means that the model will have less of a tendency to pull cold air SW into the area over the Canadian Coastal Ranges. 2) Consistency and continuity (how many times have we seen the operational run waffle after a couple of days? not this time). 3)  The ensemble runs are at lower resolution - in this pattern, I trust them less as they are too quick to bring cold air in and too quick to move it out!  3) Support from other operational models for the most part.  The exception has been the ECMWF - which has experienced a recent "upgrade" and has a weird transition, but even that model and its ensembles are showing a good deal of support for the GFS.

 

A couple of problems:  The GFS has been overdeveloping lows recently.  Look at model trends (tropicaltidbits.com is an excellent site) and look at how the cutoff that sets the block up is handled. The GFS is repeatedly having to reset it gets hit in the head over the overdevelopment. The parallel run appears more reasonable (is this what is being fixed - convective feedback?).  While the ECMWF has been more jumpy, it still is a very good model, so I'm not willing to ever write it out.

 

Things to watch for concerning snow: 1) watch Thu night and early Fri morning.  We could get a convergence zone post front (the first system that has less cold air to work with). I can smell a possible couple inches around the area by "surprise".  2) The Saturday night period. It could be interesting for fireworks time on New Years Eve.  Most models bring good convergence in here as the upper low develops into the area. We could get interesting snow ahead of the main arctic boundary even in the onshore flow.  It may be convective, so locally big amounts and possibly not much in other places at first.  3) The arctic boundary itself (will it move south or stay hung up?). I feel better for the Washington members of the forum than Oregon, but all may score.  4) The block appears to want to last a while in the right spot...so reloading looks good. Details will be very bad as the pattern evolves. Could be several interesting opportunities over the next couple of weeks though. 

 

These are just random thoughts popping out.  Even when I have access to all the data in the world, the answers don't pop up.  Models are just models and have biases of their programmers.  So I don't have the answers.  But I am excited about the potential.  Hopefully, no one here jumps off bridges when we get a bad run.

[Jesse]

Have had 4.5" here. Probably also about halfway to average.

I was low balling to make it a perfect 1/10th, illustrating how much less I have gotten.

 

Probably more like 2.5-3" total for me.

[jaya]

Really starting to come down good. 32 degrees.

Hi Snowmizer and others, if you tweet your images of snow and observations to #wawx (here in Washington), it helps the NWS with situational awareness.  You should reference your location and elevation if known.  Jaya

[luvssnow_spokane]

Mm5 showed 8 inches for me tonight

thats what she said