December 2020 Weather Observations for the PNW

[Hyperbolic Trendz]

5 minutes ago, Front Ranger said:

I think Andrew writing off December altogether was the turning point.

Well I might have read it wrong, but I think TWL just recently canceled Winter in Eugene until the end of time. He’s really testing the limits of the reverse wishcast.  Although who am I to question when it’s worked in his favor before? 

 

5 hours ago, TigerWoodsLibido said:

A Dec-Jan event of any significance will never impact areas this far south again in our lifetimes.

 

[SilverFallsAndrew]

3 minutes ago, Runtmc said:

Well I might have read it wrong, but I think TWL just recently canceled Winter in Eugene until the end of time. He’s really testing the limits of the reverse wishcast.  Although who am I to question when it’s worked in his favor before? 

 

 

That storm Eugene had in February 2019 was pretty insane. So it’s worked for him before. It’s kind of the opposite of Jim.

[SilverFallsAndrew]

Next weekend seems potentially chilly. A nice storm impacts California too. 

[TT-SEA]

4 minutes ago, SilverFallsAndrew said:

That storm Eugene had in February 2019 was pretty insane. So it’s worked for him before. It’s kind of the opposite of Jim.

Ironically Jim calmly threw in the towel on this coming event 2 days ago.    When I saw that... I thought this could be a big one!

[Esquimalt]

Does anyone have the charts of where the lows go on the GEFS?  Thanks! 

[BLI snowman]

31 minutes ago, SilverFallsAndrew said:

Some areas of the Northern Oregon Cascades and Coast range could see up to 8" of precip in the next 72 hours. Some potential for landslides and debris flows in the burn scars. Likely many of the smaller streams and coastal rivers will flood. 

Looks like 2.5"-3" or so for the valleys the next two days. Nice event, but not quite enough to ensure a wet December for the I-5 stations given how dry it's been so far.

[SilverFallsAndrew]

Salem has had 6 days of 50+ highs in a row, the past 5 have been exactly 50. Looks like they will run that streak to 9. They’ve also had rain 11 of the past 13 days, but it has been very light for the most part. 

[Cloud]

It’s another “warm” morning by Dec. standards. Currently 46F and cloudy. Never got below it overnight. 

[jakerepp]

52 minutes ago, Cloud said:

Clear PSCZ signature for the N. Sound. Someone usually scores really well inside that triangle. 

Pick me!!

[SouthHillFrosty]

Anybody living north of Seattle or In the foothills will get hit good on Monday 

[TacomaWaWx]

I’m thinking the snow probably won’t end up being much at my house. Probably some flakes in the air atleast and maybe a slushy trace at best. Someone’s gonna get something though! 

[TacomaWaWx]

Currently at 2.60” for December. Pretty good chance we get to average precipitation atleast...quite possibly above average. Looking like this month will be above average temperature wise but the number will probably come down a bit. 

[TigerWoodsLibido]

Zzzzzzzz

[FroYoBro]

The next few days down here will at least be a lot more interesting than the last week. Heavy and warm rain turning into a sharp cold front on Monday. 
 

I’ll take it. 

[FroYoBro]

1 minute ago, TigerWoodsLibido said:

Zzzzzzzz

Sorry I was wrong Andrew. Tiger is actually the #1 weenie on here. 

[wxmet]

12z GFS is warmer than the previous run at KSEA by about 4 degrees. Need the low to track further south like 6z to really stand a chance. Will be interesting to see the ECMWF 12z.

[seattleweatherguy]

Just now, wxmet said:

12z GFS is warmer than the previous run at KSEA by about 4 degrees. Need the low to track further south like 6z to really stand a chance. Will be interesting to see the ECMWF 12z.

Bummer that would effect south bothell. This feels like a rollar coaster ride where it goes up and everyone celebrates and when it goes down its bummer.

[BLI snowman]

10 minutes ago, FroYoBro said:

The next few days down here will at least be a lot more interesting than the last week. Heavy and warm rain turning into a sharp cold front on Monday. 
 

I’ll take it. 

Yep, first "highlight" of the month even if heavy rain and south wind is what we expect in the winter. I've learned not to take it for granted.

[Jesse]

10 minutes ago, FroYoBro said:

Sorry I was wrong Andrew. Tiger is actually the #1 weenie on here. 

Wow, I didn't realize I had already logged in and started posting this morning.

[Brian_in_Leavenworth]

Canadian has it going through about Seattle and then going east, slightly SE

[Jesse]

Mild, breezy night here, with a low of just 48. Looks like a good old fashioned soaker starting later today through Monday. Then sharply lowering snow levels and colder later Monday through the rest of the week. Sort of a fun progression.

[Cloud]

18 minutes ago, FroYoBro said:

The next few days down here will at least be a lot more interesting than the last week. Heavy and warm rain turning into a sharp cold front on Monday. 
 

I’ll take it. 

And the next few days is going to be quite bipolar around here as there will be a define line between snow and rain. This still looks quite marginal and not everyone will score. 

we really need an arctic air mass that entrench the region for weeks. 

[Brian_in_Leavenworth]

[Jesse]

2 minutes ago, Cloud said:

And the next few days is going to be quite bipolar around here as there will be a define line between snow and rain. This still looks quite marginal and not everyone will score. 

we really need an arctic air mass that entrench the region for weeks. 

Good point.

[wxmet]

ECMWF is further south on this run. Gonna have some nice lowland totals.

[Esquimalt]

1 minute ago, hawkstwelve said:

Roughly the same location as the 06z.

I get half as much snow on this one so I think there is a slight move south. 

[Esquimalt]

When they come out can someone please put the ensemble members low images up?  Curious to see where the average track lies relative to the op. Thank you. 

[TacomaWaWx]

We’re pretty well within the believable time range now. Seems like we’re locking in on a solution. Lot of this will be dependent on time of day...hopefully the bulk of the precip falls outside of the peak daylight hours. Either way looks like the odds have bumped up this morning. 

[bainbridgekid]

Euro looks like a beautiful track. I'd expect this run to spit out widespread 3-5" totals North and East of Seattle.

[SouthHillFrosty]

5 minutes ago, hawkstwelve said:

Bam!

This is more than any previous run has shown, I believe. Quite a bit more than the 06z and 00z at least.

Do you believe? I believe!! 

[Deweydog]

Exceptionally delicate setup.  Gonna just have to watch it play out.

[wxmet]

1 minute ago, hawkstwelve said:

For that time period (2-7PM)...

Surface temps: Either side of 35

925mb temps: 0/-1c

850mb temps: -2/-4c

Still very borderline but good precip rates should help.

What will help in this marginal situation is strong 925mb winds out of the NW that the ECMWF is depicting which will support good CAA and offset any melting from that level to the surface.

[bainbridgekid]

1 minute ago, Deweydog said:

Exceptionally delicate setup.  Gonna just have to watch it play out.

The difference between 1,000 foot and 200 foot snow levels in a setup like this is a matter of about 2 degrees. Impossible to expect models to nail things down that well, but the potential is there inside 48 hours which is more than we could say about anytime in the last 9 months.

[TT-SEA]

3 minutes ago, bainbridgekid said:

The difference between 1,000 foot and 200 foot snow levels in a setup like this is a matter of about 2 degrees. Impossible to expect models to nail things down that well, but the potential is there inside 48 hours which is more than we could say about anytime in the last 9 months.

 

Going to get buried here either way! 

[SilverFallsAndrew]

Can someone post the Oregon map? I need to know if snow will accumulate above 1500'.

[umadbro]

If the 6z or 12z verifies I'll vomit.

[wxmet]

1 minute ago, hawkstwelve said:

I would have to imagine NWS Seattle will mention something about it in their afternoon AFD.

Very precarious position to be in. Don't mention anything and it happens to occur, many people will be extremely caught off-guard when 3+ inches falls Monday afternoon/evening (let alone the more extreme amounts possible). Sound the alarm and it doesn't pan out, a bunch of angry members of the public who don't know any better will shout from their rooftops about how bad weather forecasters are here.

Sh*tty either way. 

They need to mention it at this point. Even if it’s just putting rain/snow mix in the forecast. Show min/max/likely snow maps and keep watching till Monday.

[Jesse]

Current Oregon snow pack. Doing well, near to moderately above average.

 Will be interesting to compare how these numbers look in a few days after the AR event.

 

[Dave]

16 minutes ago, Jesse said:

Current Oregon snow pack. Doing well, near to moderately above average.

 Will be interesting to compare how these numbers look in a few days after the AR event.

 

It won't be pretty.

[Winterdog]

I'm liking the Euro for my area.  Fun to follow but very marginal.  Looks like Randy is in the 6 to 8 inch area.  The convergence zone setup will be a big factor on who gets the most if any  45 currently, 3.67" for the month, 62.35" for the year.