December 2016 Observations and Model Discussion for the Pacific Northwest

[SilverFallsAndrew]

41 at PDX! Mid-40s today?

[luvssnow_spokane]

hmm longer range on the euro wants to follow the current GFS runs... not as good. 

[SilverFallsAndrew]

hmm longer range on the euro wants to follow the current GFS runs... not as good. 

 

Thank God. Let's make January Great Again.

[SilverFallsAndrew]

I'm going to be driving over to Leavenworth on Sunday and staying into Monday. By the looks of the models (as they stand now), I'll be heading from one snowy landscape to another, then back to more potential snow next week. Gotta love it!

 

Going to be gorgeous over there!

[HighlandExperience]

hmm longer range on the euro wants to follow the current GFS runs... not as good.

. The next seven days look awesome

[MR.SNOWMIZER]

hmm longer range on the euro wants to follow the current GFS runs... not as good.

Way to much going on to even look at amything past 96 hrs seriously. Models can't even nail down 60 hrs away right now.

[chopper 918]

Way to much going on to even look at amything past 96 hrs seriously. Models can't even nail down s**t 60 hrs away right now.

Exactly!!

[luvssnow_spokane]

Way to much going on to even look at amything past 96 hrs seriously. Models can't even nail down s**t 60 hrs away right now.

Sorry old habits are hard to break ... Always looking past day 10... As that has traditionally been the only thing to hang our hats on.  BUT you are right and it is looking pretty good for the coming possible event.

[MikeInEverett]

Starting to worry that the low could track too far south based on current trends. Still feel positive overall though.

[SilverFallsAndrew]

My thoughts haven't changed a ton based on one run of the EURO. I think the next week is a time of great uncertainty. When we look back on it, things will probably play out much differently than they look now. That is the nature of the beast and fine details. Some of those details may work out in our favor, some might now. We'll be doing post-mortems and looking ahead to what is next in a couple weeks. Should be a fun ride.

[Perturbed Member]

Last 4 euro runs have trended weaker and further south on that low. Wouldn't mind it going a bit more south to keep PDX all snow.

[Winterdog]

Euro says goodbye to the mid month cold shot.

[BLI snowman]

Euro says goodbye to the mid month cold shot.

 

Still shows a ton of potential through Tuesday or so. 

[SilverFallsAndrew]

PDX down to 39...No mid-40s?!

[SilverFallsAndrew]

My guess is the delay in the PDX AFD is they are about to put out a bunch of WSW's and WWA's...

[seattleweatherguy]

For seattle we can't have it go too far south...

[Perturbed Member]

My guess is the delay in the PDX AFD is they are about to put out a bunch of WSW's and WWA's...

 

The PDX night shift guys said today's day shift guys would likely go for WSWs.

[Perturbed Member]

For seattle we can't have it go too far south...

Let's negotiate a track that maximizes snow for both locations and then convey this info to the low.

[χιόνι (chióni)]

Sure is nice not to have to hang all our hats on one potential event.

From the Seattle AFD:

 

.LONG TERM...An active weather pattern is likely with a tricky

balance between the northern and southern streams--there will likely

be blocking around Alaska. This should make for a low snow level and

give the lowlands periodic flirtations with snow. Fraser outflow

could continue at times through the weekend but probably will not be

especially strong. Looking at the 12z GFS...there is a chance that a

weather system around Sunday night will be problematic for Western

Washington as the modified arctic front could push back south into

Western Washington at that time. The 00z ecmwf looks like there

could be light to moderate outflow through the weekend into the

Bellingham area, but keeps southerly gradients and milder weather

for most of Western Washington with no shift south. Then around 12z

Tuesday of next week the euro takes a southern stream low pressure

center and frontal system into Oregon--and Fraser outflow resumes as

the arctic front strengthens.

 

And that's all after Thursday's storm.

Still sticking to 1 inch forecast Thursday into Friday?

[luvssnow_spokane]

Which is the most important time-frame at this point. I don't understand people looking out 10+ days when we have tons of potential through the short(er) range. Makes no sense to me.

Because the shorter range may fail Horribly ...       <_ plan b>

[Perturbed Member]

Which is the most important time-frame at this point. I don't understand people looking out 10+ days when we have tons of potential through the short(er) range. Makes no sense to me.

 

This. Some people always like to track the clown range even with an event like Thursday within close range. Strange.

[Winterdog]

Which is the most important time-frame at this point. I don't understand people looking out 10+ days when we have tons of potential through the short(er) range. Makes no sense to me.

You've gotta look! Are you saying you don't even look? I don't put much stock in it but I just have to give it a peek.

[BLI snowman]

Which is the most important time-frame at this point. I don't understand people looking out 10+ days when we have tons of potential through the short(er) range. Makes no sense to me.

 

Models are going to have a nightmare of a time figuring out the extent of the northern stream energy, as is always the case when you have a major supply of cold air trying to make a collective push down into the lower 48. It's still playing out as we speak with the Thursday storm getting moved around with each new run, so it's going to be a while yet before the early next week action is clear.

 

One thing that does seem clear is that the two branches will be interacting at some points in the next 7-8 days. Very baroclinic environment. Lots of rain for some, lots of snow for others.

[Kayla]

My thoughts haven't changed a ton based on one run of the EURO. I think the next week is a time of great uncertainty. When we look back on it, things will probably play out much differently than they look now. That is the nature of the beast and fine details. Some of those details may work out in our favor, some might now. We'll be doing post-mortems and looking ahead to what is next in a couple weeks. Should be a fun ride.

 

PDX will see a lot more snow than a T-1". There isn't a single model showing this even if a (GEM) high strength low curves way north of PDX it's still likely looking at 1-3" before a changeover. 

[Deweydog]

Not so sure, I think by Friday morning the stratiform stuff will be over and the west winds will punch in rather uniformly. Most of Thursday looks like it could stay snow, especially near or north of the gorge. 

 

It's a tough call right now.  I'd lean toward a 50/50 away from the gorge, 25/75 in the typical outflow spots due to the prolonged nature.  I'm never too comfortable assuming low level mixing will be as aggressive as modeled, although that bias seems to be improving over the years.  It's been a long time since January 2004.  

[luminen]

Just wait for January guys. It'll be even better. 

 

But yeah, I'm loving the 30F and sunny weather. So rare!

[SilverFallsAndrew]

I still think the early December 1994 event is a good analog

[luvssnow_spokane]

So you are going to watch the long range, which has much higher potential to fail, over the short range, which has much less potential to fail, because your nervous about the potential to fail?

NO.... It was sarcasm... Geesh...  Okay.. I gotta get back to analyzing next weeks outcome. 

[Front Ranger]

I'm so stoked for you all right now. This is the most promising setup in years for widespread lowland snow (Feb 2014 for OR, Jan 2012 for WA), and it's coming early in the season without even a full-scale Arctic outbreak.

Crossing my fingers!

[Deweydog]

I still think the early December 1994 event is a good analog

 

I disagree.  That system was a clipper which had cold advection associated with it.  Much more like December 30, 2003 just with a slightly drier air mass to play with going into it.  

 

This is a much more traditional overrunning situation with much stronger offshore gradients and a lot more warm advection/no cold advection.  

[Goducks09]

Where's DJ?  Would like to hear his thoughts on the ECMWF as well...

[EA_TTD]

I still think the early December 1994 event is a good analog

Did someone say analog?

 

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/gifs/500hgt_comp_12gfs814.gif

[luvssnow_spokane]

looking to hit about 40 or 41 today at my place... Lots of sun!

[Timmy]

Nice north breeze in scappoose

[SilverFallsAndrew]

Up to 43 now at PDX. Wow.

[Deweydog]

Up to 43 now at PDX. Wow.

 

They had a morning low in the upper 30's and the sun is coming out.  Not rocket science.  

[FroYoBro]

They had a morning low in the upper 30's and the sun is coming out.  Not rocket science.  

 

Yeah, today has nothing going for them. Tomorrow should be quite a bit cooler with offshore flow and a colder night.

[Perturbed Member]

Still no new discussion from NWS.

[FroYoBro]

Still no new discussion from NWS.

 

It is going to be the most detailed and beautifully written discussion ever released. 

[SilverFallsAndrew]

It is going to be the most detailed and beautifully written discussion ever released. 

 

Probably copy/paste