December 2023 Weather in the PNW

[Gradient Keeper]

2 hours ago, Meatyorologist said:

That is an awesome windstorm pattern out this way. At least it's not atrociously boring.

Yeah, we need to keep a close eye on that.

12z GFS in 1 hour 56 minutes

[SilverFallsAndrew]

16 minutes ago, Gradient Keeper said:

At least the Night Shift 6z GEFS is much better long range. Day 10-16 is active with Cascade snows as we're on the cooler side of the jet.

Probably the best we can hope for.

[TT-SEA]

7 years ago today we were digging out.   

[ShawniganLake]

2 hours ago, Gradient Keeper said:

At least the Night Shift 6z GEFS is much better long range. Day 10-16 is active with Cascade snows as we're on the cooler side of the jet.

That strong Aleutian low is throwing some punches at the PV as we near Christmas.  

[TT-SEA]

12Z GFS really dries things out after today for at least the next 10 days.    SEA is running almost 5 inches above normal for December right now.    Pretty crazy.

[Phishy Wx]

Rain and 34

looks like we got about 4-5" but also looks like compaction and some melting already.  looked a lot fluffier when I went to bed at 1:30am

[Phishy Wx]

7 hours ago, Phil said:

YIKESSSSS

Canada burned this summer with fires, now 'burning' via Nino

[Phil]

5 hours ago, Meatyorologist said:

Wow. 06z GFS. Somehow all the mild Pacific air you could ask for without any of the beneficial precipitation associated with it. Barph

A lot more STJ with the next AR pattern. The southward migration of the storm track towards CA might be starting.

[Phil]

3 hours ago, Gradient Keeper said:

At least the Night Shift 6z GEFS is much better long range. Day 10-16 is active with Cascade snows as we're on the cooler side of the jet.

Cool side of the STJ but warm side of the northern jet. That pattern will verify warmer than normal everywhere except CA.

[Phishy Wx]

sloppy out

 

[Phil]

16 minutes ago, ShawniganLake said:

That strong Aleutian low is throwing some punches at the PV as we near Christmas.  

That is true, the AL will trigger a wave-1 response (displacement off the pole) and should begin to slowly weaken the vortex with time. So at the very least the cold will be free to move off the pole somewhat (no locked in super PV/++AO).

In such a strong Niño, though, the PNW lowlands probably need a wave-2 (split) which will require help from Eurasia in addition to the wave-1. That has been hard to come by thus far.

2015/16 also never got the wave-2/split, despite lots of teasing in the longer range models. Maybe this year will do better..the QBO is more favorable for downward propagation if ma’ nature decides to play ball.

[Phil]

Man oh man. Check out the agreement at D15 across the EPS/GEPS/GEFS ensemble means.
Scandinavia trough and +EPO/building STJ. Hard to find a more perfect blowtorch pattern for west-central Canada.

[SilverFallsAndrew]

1.45” in the past 24 hours. Up over 11”

on the month. We’ve essentially hit average for the month already. I believe PDX has locked up an above average rainfall month. 

[SilverFallsAndrew]

2 minutes ago, Phil said:

Man oh man. Check out the agreement at D15 across the ensembles.  Scandinavia trough and +EPO/building STJ. Best possible torch pattern for west-central Canada.

Looks like a you problem. The CME and GEFS would pound us with rain and mountain snow. 

[Phil]

12 minutes ago, SilverFallsAndrew said:

Looks like a you problem. The CME and GEFS would pound us with rain and mountain snow. 

Verbatim that is not a legit torch pattern here. Up north is a different story of course.

Knowing how these types of patterns work and how ensemble mean smooth them, you guys will likely end up with substantially greater positive departures.

[LowerGarfield]

.99 inches in about twelve hours is a lot here. No snow.

[TacomaWx]

0.28” since midnight and 6.79” MTD. Already above average rainfall this month. Might be able to hit 10” of rain this month. I can’t remember the last time we hit 10” of rain in a month…but it’s been a couple years atleast. 

[SilverFallsAndrew]

3 minutes ago, LowerGarfield said:

.99 inches in about twelve hours is a lot here. No snow.

Wow. Make the desert bloom!

[SilverFallsAndrew]

4 minutes ago, TacomaWx said:

0.28” since midnight and 6.79” MTD. Already above average rainfall this month. Might be able to hit 10” of rain this month. I can’t remember the last time we hit 10” of rain in a month…but it’s been a couple years atleast. 

My uneducated guess says we dry out for about two weeks, and then things ramp up again. 

[SilverFallsAndrew]

6 minutes ago, Phil said:

Knowing how these types of patterns work and how ensemble mean smooth them, you guys will likely end up with substantially greater positive departures than down here.

@TT-SEA would confirm usually wet means warm. I would say usually but not always, this year, definitely. 

[TacomaWx]

3 minutes ago, SilverFallsAndrew said:

My uneducated guess says we dry out for about two weeks, and then things ramp up again. 

Yeah, I think we will get some decently wet weather again at some point this month…but probably not as wet as the first 10 days. 

[Phil]

Just now, SilverFallsAndrew said:

@TT-SEA would confirm usually wet means warm. I would say usually but not always, this year, definitely. 

If you’re looking for real cold, it will be in Mother Russia. Not in the cards for North America this winter (and I mean everywhere in North America, not just the west).

CA and the SE 1/3rd of the US are the only areas that can pull off negative departures in such a pattern, but that is not arctic cold. Just a displacement of cooler midwestern air that would be warm by their standards (and in CA’s case it’s a precip induced cool anomaly).

[Phil]

Of course my anemometer decides to croak when I have a back injury.  No way in hell I could shimmy up the chimney in my current state, lol.

I’ll probably have to pay a friend to help me out bc I can’t mentally tolerate having incomplete wx data. I don’t know Tim does it.

[BLI snowman]

4 minutes ago, Phil said:

If you’re looking for real cold, it will be in Mother Russia. Not in the cards for North America this winter (and I mean everywhere in North America, not just the west).

CA and the SE 1/3rd of the US are the only areas that can pull off negative departures in such a pattern, but that is not arctic cold. Just a displacement of cooler midwestern air that would be warm by their standards (and in CA’s case it’s a precip induced cool anomaly).

Decent chance we see our warmest winter on record nationally. 

[Blizzard777]

19 minutes ago, TacomaWx said:

0.28” since midnight and 6.79” MTD. Already above average rainfall this month. Might be able to hit 10” of rain this month. I can’t remember the last time we hit 10” of rain in a month…but it’s been a couple years atleast. 

Across the pond 

[TT-SEA]

Some blue sky is Seattle this morning. 

[Rubus Leucodermis]

11 hours ago, Gradient Keeper said:

The enthralling block-o-rama Split Flow City Euro run is about to begin. I can hardly wait. Oh yeah. No, no sarcasm at all. None.

FTFY.

[Rubus Leucodermis]

1.06" yesterday, 0.40" since midnight, 7.69" for the month. 41.9˚F.

[Phil]

16 minutes ago, BLI snowman said:

Decent chance we see our warmest winter on record nationally. 

Oh easy. And the entire continent.

The parts of North America that typically see the greatest amplitude of winter temp anomalies (warm or cold) are set up roast in this type of low frequency state, so that will skew the mean heavily warm. And the weak ass negative departures in CA/SE-US are barely a drop in the bucket by comparison.

The cold air source simply won’t exist. This regime would need a massive subseasonal kick to the balls just to lose its balance, let alone drop.

[Timmy Supercell]

12 minutes ago, BLI snowman said:

Decent chance we see our warmest winter on record nationally. 

The world has apparently done that consecutively in the last few years. 

[Rubus Leucodermis]

9 hours ago, Chewbacca Defense said:

Up to .96" of rain on the day, and after that initial spike at 40 degrees this morning, we have been around 34-36 the rest of the day and into tonight.  Didn't see anything fall today that resembled whet snow.  There were some barely positive splats and that's it.  I think they did better right up against the border and above 1,000 feet or so, but nothing for a vast majority of us knuckle dragging lowlanders.

From the reports I’ve seen, Lynden got snow for an hour or two.

[ShawniganLake]

1 hour ago, Phil said:

Cool side of the STJ but warm side of the northern jet. That pattern will verify warmer than normal everywhere except CA.

Is the pattern being depicted quite a bit different than Dec 2015?   Mid December through early January was rather chilly and active here with multiple days with snow falling.  No big snow storms but many wet snow and mixed precip events. 

[Phil]

While we slog thru the typical December niño doldrums, I finally found time to upload some wx videos to my channel.

Lightning compilation part-2 (of 3) and 2 snowstorms from winter 2021/22 (Jan & Mar).

 

[Mercurial]

38 minutes ago, TT-SEA said:

Some blue sky is Seattle this morning. 

Nice.  I haven't seen legit blue sky since mid November, and I doubt I'll get any during our upcoming ridgefest, either.

[Mercurial]

Winter sun is definitely an advantage SW Montana has over NW Montana.  Especially here in the Flathead, where we get a super thick cloud deck during ridges.  Even my indoor plants are struggling with the permadarkness.

[Slushy Inch]

Definitely getting 2015 vibes. Any interesting weather will likely be more AR.

[ShawniganLake]

1.82” of liquid precip from yesterday’s storm here. Not bad!

[TT-SEA]

2 minutes ago, Slushy Inch said:

Definitely getting 2015 vibes. Any interesting weather will likely be more AR.

As expected... the 12Z run yesterday was too extreme with that low cutting off so far to the south and west.   It's been trending back closer to the west coast.

[TT-SEA]

Saturday looks quite warm for the foothills... and this time it doesn't show heavy rain with the warmth.

[SilverFallsAndrew]

Good news though. Pretty much every long range model is showing a Nina developing by next summer.