December 2019 Weather Discussion for the PNW

[Guest CulverJosh]

Need precip for snow levels to matter... models look pretty dry next weekend.

Here we go.

[TacomaWaWx]

Yeah still looks pretty boring overall through mid December now.

[TT-SEA]

Here we go.

Go where? Andrew basically just said the same thing.

[Guest CulverJosh]

Go where? Andrew basically just said the same thing.

Dry bias. Too early to know it’ll be dry. Looks pretty wet down here. The low will shift a few times in a week.

[Brian_in_Leavenworth]

Brian in Leavenworth was right. The Saturday system goes into Norcal now, dry and chilly next Saturday/Sunday. Turns into a nice snow event for SLC and Denver. 

Just like the Thanksgiving week storm.

[TT-SEA]

Dry bias. Too early to know it’ll be dry. Looks pretty wet down here. The low will shift a few times in a week.

Then too early to know about how cold the air mass will be as well.

 

Call out Andrew for saying it looks dry. Of course it does.

 

We won't be here... so don't really care. Would prefer it to be very wet.

 

Also... leaning towards dry has been absolutely the way to go for the last 6 weeks.

[Gradient Keeper]

18z NWS/NCEP Pacific Surface Analysis

 

Cyclogenesis! Cyclogenesis everywhere! Over the next 18-24 hours three major areas of low pressure are forecast to deepen with two to 972mb and the main one near the Eastern Aleutians down to 953mb. The WPAC jet is kicking into overdrive and is going to try to beat down the ridging over us. C'MON!!!!

 

[Timmy]

Starting to fight those sun angles by then...

increasing solar too

[Guest CulverJosh]

Then too early to know about how cold the air mass will be as well.

 

Call out Andrew for saying it looks dry. Of course it does.

 

We won't be here... so don't really care. Would prefer it to be very wet.

 

Also... leaning towards dry has been absolutely the way to go for the last 6 weeks.

Just that climatology is well in our favor at this point.

 

I just don’t see a repeat of last year. The storms are going to break through earlier it is looking like.

 

Not nearly the incessant ridging we had last year. And Alaska has been more active. It does mean something.

[SilverFallsAndrew]

Then too early to know about how cold the air mass will be as well.

 

Call out Andrew for saying it looks dry. Of course it does.

 

We won't be here... so don't really care. Would prefer it to be very wet.

 

Also... leaning towards dry has been absolutely the way to go for the last 6 weeks.

 

Yeah, there is precip and possibly decent mountain snows between now and then, but next weekend is looking dry for most of Oregon and Washington now. It looks like a situation where temps could get pretty chilly so I won't complain. Plus we have outdoor activities next weekend so dry and crisp would be perfect. 

[SilverFallsAndrew]

Really nice mountain snow producer in the long range. 

[TT-SEA]

Just that climatology is well in our favor at this point.

 

I just don’t see a repeat of last year. The storms are going to break through earlier it is looking like.

 

Not nearly the incessant ridging we had last year. And Alaska has been more active. It does mean something.

Great.

 

More precip would likely mean everything is farther north and it's not as cold as shown. Whatever.

 

We are not talking about the rest of December or the rest of winter. Just next weekend. Andrew said the snow levels look really low up here but the models also show it being dry at this point.

 

He made a comment about the latest GFS run for next weekend... and I added that there is not much precip shown at that time. Somehow I am now making a prediction for the rest of the winter?

[TacomaWaWx]

50 degrees and cloudy here. Had 0.02” of precip this morning...0.57” for December. If the 18z verifies through day 7 we will be at 2 inches of rainfall mid way through December. This will be the 4th December in a row at my location to be below normal in rainfall unless the jet stream really gets going in the second half of the month. Haven’t had a really wet December since 2015.

[Omegaraptor]

You know the weather is interesting when it's December and we're going over an hour between posts.

[Front Ranger]

Going to go through most of the 11/20-12/20 period without any impressive cold in the lower 48, the cut-off trough at Thanksgiving in the SW notwithstanding. 

 

DEN hit -2 on 11/27, only the third time they've gone below 0 in November since 1983. 

 

And it's too soon to say there won't be more major cold in the lower 48 by 12/20.

[TigerWoodsLibido]

Seahawks time...maybe focusing more on ballgames can help ease the boredom of the models of late.

[Front Ranger]

Seems like a lot of false narratives get pushed here. One of which is that there has been major blocking this season...Just not true. There was some blocking early on, but it definitely has not established as a theme. 

 

There was plenty of fall blocking. Let's not get too caught up in our own backyards.

 

 

 

The question is when does it return this winter and become favorable/more exciting for your area again. 

[Omegaraptor]

There was plenty of fall blocking. Let's not get too caught up in our own backyards.

 

fallblocking.gif

 

 

The question is when does it return and become favorable/more exciting for your area again. 

 

I think we're overlooking that airmass we had in late September - truly top tier cold for that time of year. A ton of cold records and early snow records fell with that airmass, some going back over a century. Hillsboro had its coldest September high on record and downtown Portland failed to break 50 (also coldest September high on record).

 

Wenatchee's previous September record was 49, but that airmass brought a high of 47, then a high of 43 the very next day.

[Front Ranger]

There was plenty of fall blocking. Let's not get too caught up in our own backyards.

 

fallblocking.gif

 

 

The question is when does it return this winter and become favorable/more exciting for your area again. 

 

Pretty hard to have this happen without much blocking.

 

[MossMan]

Pretty hard to have this happen without much blocking.

 

60dTDeptUS.png

Looks like Phil moved to west Texas...A lot of hot air in one area!

[TacomaWaWx]

I think we're overlooking that airmass we had in late September - truly top tier cold for that time of year. A ton of cold records and early snow records fell with that airmass, some going back over a century. Hillsboro had its coldest September high on record and downtown Portland failed to break 50 (also coldest September high on record).

 

Wenatchee's previous September record was 49, but that airmass brought a high of 47, then a high of 43 the very next day.

I think the boring weather since the beginning of November has made people forget that September and October were actually pretty interesting. There was a fairly wet period with a decent amount of thunderstorms and rain for lots of us in September regionally. Then there was several troughs in late September through Halloween that were historic air masses for that time of the year. Was a fairly active week of storms and rain up in western WA in Mid October too. It was a pretty interesting fall minus November IMO.

[Front Ranger]

I think we're overlooking that airmass we had in late September - truly top tier cold for that time of year. A ton of cold records and early snow records fell with that airmass, some going back over a century. Hillsboro had its coldest September high on record and downtown Portland failed to break 50 (also coldest September high on record).

 

Wenatchee's previous September record was 49, but that airmass brought a high of 47, then a high of 43 the very next day.

 

The combination of the late September air mass along with the two other big ones for the West/Plains in October was pretty much unprecedented for that early in the season. 

 

Then the East had a top tier cold air mass in early November.

[El_Nina]

Air is pretty stagnant so the low levels have developed a smog layer.

[ShawniganLake]

Daffodils

 

[Front Ranger]

I've definitely seen worse GEFS means in the LR.

 

[ShawniganLake]

I've definitely seen worse GEFS means in the LR.

 

gfs-ens_z500a_namer_48.png

Could get wet and potentially stormy

[Front Ranger]

Could get wet and potentially stormy

 

Plenty of potential for the second half of the month.

[SilverFallsAndrew]

48/41 so far today. Currently 41. 

[SilverFallsAndrew]

Next weekend looks chilly on the 00z. 

 

[umadbro]

Garbage Seahawks game. Similar to what the rest of the winter has in store for us.

[umadbro]

Next weekend looks chilly on the 00z.

 

Yay. Low 40's for highs and sunny.

[ShawniganLake]

Plenty of potential for the second half of the month.

Could be some cold onshore flow. I’d bet against arctic air at this point.

[Front Ranger]

Could be some cold onshore flow. I’d bet against arctic air at this point.

 

Way too soon to say. Things can change very quickly.

[umadbro]

Could be some cold onshore flow. I’d bet against arctic air at this point.

Artic air looks pretty unlikely through December.

[SilverFallsAndrew]

May be enough mountain snow over the next couple weeks to comfortably put the legendary bad years behind us. 

[HighlandExperience]

May be enough mountain snow over the next couple weeks to comfortably put the legendary bad years behind us.

04/05 comparison can be put to rest at least

[fubario]

Garbage Seahawks game. Similar to what the rest of the winter has in store for us.

I'm a happy Rams fan. Seahawks thought they could just show up and win and sometimes you get humbled. That's the NFL!

 

Looking forward to some mountain snow! Lets go GFS and Euro!

[Cloud]

I'm a happy Rams fan. Seahawks thought they could just show up and win and sometimes you get humbled. That's the NFL!

 

Looking forward to some mountain snow! Lets go GFS and Euro!

Eh? I don’t know who thought they could roll into LA and win. Rams/Hawks games are always tough. Tonight was a bad bad game for this team.

[Gradient Keeper]

00z GFS after Day 7 the flow consolidates nicely, no split-flow, and looks like a La Nina pattern if anything.

 

Go Chiefs!

 

00z ECMWF in 1 hour 3 minutes

[Phil]

Big block develops over Scandinavia this run.

 

That’s what I like to see.