December 2023 Weather in the PNW

[Gradient Keeper]

Day 7 (4-run trend)

[TT-SEA]

Just now, Gradient Keeper said:

Day 7 (4-run trend)

Big difference.   Looks much more like the recent GEM solutions with an open trough and no cut-off low.

[Gradient Keeper]

1 minute ago, TT-SEA said:

Big difference.   Looks much more like the recent GEM solutions with an open trough and no cut-off low.

Indeed, Tim.

[Gradient Keeper]

Day 8

[Gradient Keeper]

850s pretty cold north Washington Cascades

[TT-SEA]

3 minutes ago, Gradient Keeper said:

Indeed, Tim.

If 00Z ECMWF goes this way then it's Canada for the win!

[Gradient Keeper]

Day 9'er

[Gradient Keeper]

This run transitions from El Nino to something more resembling La Nina.... Nice.

00z ECMWF in 1 hour 10 minutes

[snow_wizard]

2 hours ago, Cascadia_Wx said:

VUO is a long term station, and it has been jacked up pretty royally at times over the years, for extended periods. Both on the warm side and the bad side.

Also I just don’t think your explanation really holds water. They are really going to perform so vastly different every night there’s radiational cooling, compared to how they have behaved for decades, because of some subtle change in offshore flow tendencies this year?

I think OLM has had trouble getting dry in place this season due to a lot of instances of weak northerly gradients, which have failed to punch north winds that far south, instead of strong offshore flow.  Usually when we get blasted with east wind here they are really cold.  This year there just hasn't been any east wind at all here.  I think there is some correlation.

[snow_wizard]

1 minute ago, Gradient Keeper said:

This run transitions from El Nino to something more resembling La Nina.... Nice.

00z ECMWF in 1 hour 10 minutes

I'm pretty encouraged by the ECMWF weeklies and GEFS extended both showing some potential in January.  Maybe the models are starting to factor in possible influence from the SSW the ECMWF has been advertising very late this month.

[Gradient Keeper]

Day 10

[TT-SEA]

1 minute ago, snow_wizard said:

I think OLM has had trouble getting dry in place this season due to a lot of instances of weak northerly gradients, which have failed to punch north winds that far south, instead of strong offshore flow.  Usually when we get blasted with east wind here they are really cold.  This year there just hasn't been any east wind at all here.  I think there is some correlation.

Also interesting that there has been lots of east wind here in the last couple months.   I know it comes down to the angle of the flow through the passes for central and south King County.

[Gradient Keeper]

Just now, snow_wizard said:

I'm pretty encouraged by the ECMWF weeklies and GEFS extended both showing some potential in January.  Maybe the models are starting to factor in possible influence from the SSW the ECMWF has been advertising very late this month.

Yep! It's going to be AWESOME!

[Cascadia_Wx]

1 minute ago, snow_wizard said:

I think OLM has had trouble getting dry in place this season due to a lot of instances of weak northerly gradients, which have failed to punch north winds that far south, instead of strong offshore flow.  Usually when we get blasted with east wind here they are really cold.  This year there just hasn't been any east wind at all here.  I think there is some correlation.

I’m just not seeing that as a sufficient explanation for the sudden sea change in their radiational prowess within the last month and a half, which has encompassed a variety of flavors of dry weather/offshore flow patterns.

[snow_wizard]

2 minutes ago, TT-SEA said:

Also interesting that there has been lots of east wind here in the last couple months.   I know it comes down to the angle of the flow through the passes for central and south King County.

Indeed.  The gradient angle is everything.  When you get east winds there is a little bit of southerly component to the surface gradient.  When I do there is a little bit of northerly component.  When it gets windy here that dry air easily shunts down to the South Sound.

[snow_wizard]

4 minutes ago, Cascadia_Wx said:

I’m just not seeing that as a sufficient explanation for the sudden sea change in their radiational prowess within the last month and a half, which has encompassed a variety of flavors of dry weather/offshore flow patterns.

You could be right.  On the other hand, last night they had sopping wet air and it was never able to clear out.  That resulted in their min being very mild.

[Blizzard777]

Still froggy 

36* 

[snow_wizard]

7 minutes ago, Gradient Keeper said:

Yep! It's going to be AWESOME!

As some have mentioned on here...It would be incredibly ironic if a strong Nino finally gets the January monkey off our back.

[CliffMassYelledAtMe]

30 minutes ago, RentonHill said:

Saving this

 

Right after MLK Day, huh? Who was calling for that?

[Cascadia_Wx]

1 minute ago, snow_wizard said:

You could be right.  On the other hand, last night they had sopping wet air and it was never able to clear out.  That resulted in their min being very mild.

A station error could also explain that. I’ve seen them get pretty chilly pretty frequently in the past despite low clouds/fog/high humidity, etc.

“Something’s up this year” definitely feels more fun though.

[snow_wizard]

1 minute ago, Blizzard777 said:

Still froggy 

36* 

34 here.  The fog has gotten shallow enough that you can see the stars above.

[Gradient Keeper]

00z GFS re-cap. 10 Day GIFs: 500mb Height Anomaly, 850mb Temps, 1000-500mb Thickness/MSLP/Precip

[Gradient Keeper]

00z GFS 10 Day Rainfall, Snowfall totals

[snow_wizard]

The GFS has a fair run of decently chilly weather during week 2.  Below normal 850s for 5 or 6 days.

[crf450ish]

1 hour ago, Snownerd3000 said:

Back loaded winter here we come 

Isn't that the case around here every year? 

 

Other than a few outliers?

[skywatcher]

18 minutes ago, snow_wizard said:

34 here.  The fog has gotten shallow enough that you can see the stars above

35 at mine. Fog's cleared out, visibility is once again crisp and the stars are out.

So are the planes on approach to SeaTac. Welcome sight after the super low-vis fog earlier this evening, driving was a little fun in that.

[Cascadia_Wx]

Meanwhile OLM sitting at a Tonga/GLAAM/UJEAS driven 42 with clear skies.

[Deweydog]

3 minutes ago, Cascadia_Wx said:

Meanwhile OLM sitting at a Tonga/GLAAM/UJEAS driven 42 with clear skies.

Overcast with mist maybe?

[TigerWoodsLibido]

TOUCHDOWN!!!

[TigerWoodsLibido]

Some dawgs back in there.

[Gradient Keeper]

00z ECMWF Day 1 pivotal seems to be having issues, so it's taking a bit longer.

[Gradient Keeper]

Day 2

[Gradient Keeper]

Day 3

[Gradient Keeper]

Day 4

[Gradient Keeper]

Day 5

[Gradient Keeper]

Day 6

[Gradient Keeper]

Day 7

[Gradient Keeper]

Day 8

[Gradient Keeper]

Day 9'er

[SouthHillFrosty]

Reports of hail/graupel at 34 degrees in South Hill? Dry and haven’t left heavy fog all day.