December 2020 Weather Observations for the PNW

[High Desert Mat?]

37 minutes ago, SilverFallsAndrew said:

18z looks like an absolute torch fest. 

Huge warm outlier. 

[umadbro]

Just now, High Desert Mat? said:

Huge warm outlier. 

Not gonna share the ensembles?

[Brian_in_Leavenworth]

18Z looks like pretty normal December temps for the most part, with a few warmer days mixed in here and there.  Nothing cold enough for Western WA and OR, but the mountains and Eastern areas get a lot of snow, which looks like normal December  weather.   A torch fest would mean flooding and little  snow for the mountains.

[Brian_in_Leavenworth]

The ensemble mean did look cooler than the operational.  Didnt see that stretch of a few days in the long range with warm temps. 

[BLI snowman]

10 minutes ago, Brian_in_Leavenworth said:

18Z looks like pretty normal December temps for the most part, with a few warmer days mixed in here and there.  Nothing cold enough for Western WA and OR, but the mountains and Eastern areas get a lot of snow, which looks like normal December  weather.   A torch fest would mean flooding and little  snow for the mountains.

Mild nights and 45+ highs at this time of year means warmth. Probably not more than one or two below average days for the lowlands on the 18z in the next 16.

[Rubus Leucodermis]

41 minutes ago, BLI snowman said:

Mild nights and 45+ highs at this time of year means warmth. Probably not more than one or two below average days for the lowlands on the 18z in the next 16.

The average high for December at KSEA is 46°F.

[Chewbacca Defense]

9 hours ago, Rubus Leucodermis said:

Something that only happens once per year.

Unless you cross the dateline.    Kinda crazy to get on a plane in Japan late Saturday afternoon and land in Vancouver Saturday morning.

[Rubus Leucodermis]

3 minutes ago, Chewbacca Defense said:

Unless you cross the dateline.    Kinda crazy to get on a plane in Japan late Saturday afternoon and land in Vancouver Saturday morning.

When camping, I usually take a shortwave set along with me and often listen to Radio New Zealand. When the news comes on, it is tomorrow’s news. When I read Around the World in Eighty Days, the surprise plot twist at the end wasn’t a surprise to me. I kept saying to myself “wait… they went around the world in an easterly direction, they had to gain a day.”

[Tyler Mode]

8 minutes ago, Chewbacca Defense said:

Unless you cross the dateline.    Kinda crazy to get on a plane in Japan late Saturday afternoon and land in Vancouver Saturday morning.

It was fun when I booked my trip to New Zealand and Bora Bora.  Trying to schedule flights and hotels, skipping nights one way, and staying "the same" night on the way back. 

[Brian_in_Leavenworth]

1 hour ago, BLI snowman said:

Mild nights and 45+ highs at this time of year means warmth. Probably not more than one or two below average days for the lowlands on the 18z in the next 16.

Sure, the nighttime lows are a bit warm due to clouds, but you have normal snow levels in the mountains and normal high temps.  That is not cold, of course, but not torching. When I think of torching, I think of a pineapple express and rain in the mountains.  And I definitely do not get snow when we have warmer than normal temps, and I am expecting snow late this weekend and next week.  Maybe just a matter of semantics. 

[SilverFallsAndrew]

62 in Eugene today. Tied the record high from 2015 and 1939 (oof).

All time record low of -12 was set today at Eug and SLE in 1972. Silver Falls all time record of -9 was set that day as well. Of course NWS doesn’t recognize those numbers as the records. For Eugene they go with the -10 from 2013.

[Meatyorologist]

The new normal.

Hopefully the upcoming zonal flow will churn up those waters a bit and cool off the bathtub.

[BLI snowman]

56 minutes ago, Rubus Leucodermis said:

The average high for December at KSEA is 46°F.

Cool. Average to above average highs and mild lows (as stated in the post) doesn't generally yield a lot of cold departures.

[Chewbacca Defense]

29 minutes ago, Tyler Mode said:

It was fun when I booked my trip to New Zealand and Bora Bora.  Trying to schedule flights and hotels, skipping nights one way, and staying "the same" night on the way back. 

I worked with a customer in Japan, and it was interesting in the beginning figuring out deadlines for deliverables..."is that your Thursday or my Thursday" 

My flight over was pretty brutal, I got on the plane about 1pm Monday and finally got to the hotel about 11pm Tuesday. night.  The return flight went better, I was so incredibly hung over I passed out and slept most of the trip.  It was still weird to get on the plane in the afternoon and then land the morning of the same day

I work in commercial aerospace, and we occasionally had to hand carry parts to Asia or Australia.  Our employee would fly there, hand the part off to an airline maintenance worker, then catch the very next flight (usually one the same plane.)

 

I cannot even imagine how messed up their body clock/calendar got.

[BLI snowman]

32 minutes ago, Brian_in_Leavenworth said:

Sure, the nighttime lows are a bit warm due to clouds, but you have normal snow levels in the mountains and normal high temps.  That is not cold, of course, but not torching. When I think of torching, I think of a pineapple express and rain in the mountains.  And I definitely do not get snow when we have warmer than normal temps, and I am expecting snow late this weekend and next week.  Maybe just a matter of semantics. 

I think it'll be hard to see December staying below +2F or so at the current pace, but the last part of the month is obviously still lala land.

[High Desert Mat?]

1 hour ago, umadbro said:

Not gonna share the ensembles?

Come on, don’t be mad bro

[Rubus Leucodermis]

4 minutes ago, BLI snowman said:

Cool. Average to above average highs and mild lows (as stated in the post) doesn't generally yield a lot of cold departures.

Your post talked about “45+” temperatures as if they were a major torchfest. Not necessarily so. 46 > 45.

[BLI snowman]

1 minute ago, Rubus Leucodermis said:

Your post talked about “45+” temperatures as if they were a major torchfest. Not necessarily so. 46 > 45.

No, I said average (45/46) or above average highs paired with mild lows will be yielding warm anomalies for the region. Pretty simple.

[Jesse]

2 hours ago, luminen said:

Not really. 

It's been socked in with heavy rain here all day and very dark @10C. Sun angles mean nothing this time of year. 

The low sun angles this time of year absolutely play a large role in driving inversion conditions, like those in the post I was responding to.

Sun angles definitely mean less in well mixed, stormy conditions like you are describing, but that's true any time of year.

 

[Rubus Leucodermis]

2 minutes ago, BLI snowman said:

No, I said average (45/46) or above average highs paired with mild lows will be yielding warm anomalies for the region. Pretty simple.

Normally our lows, like our highs, are pretty mild. That’s not torchy; it’s merely average.

[Chewbacca Defense]

.99" in the rain gauge, looks like we have another band of rain headed this way to push us past 1"

 

 

[Jesse]

Most of the bad changes on the 18Z GFS seem to be out beyond hour 180. The big period I have been watching is the weekend (potential for a snowpack destroying warm rain event) and the upper levels still cool pretty fast after about 12 hours on this run.

[Jesse]

2 minutes ago, Rubus Leucodermis said:

Normally our lows, like our highs, are pretty mild. That’s not torchy; it’s merely average.

Average low is about 34-35 for December down here, so lows around 40 represent a +5 or +6 departure, which is pretty torchy. This stuff isn't rocket science.

[BLI snowman]

12 minutes ago, Rubus Leucodermis said:

Normally our lows, like our highs, are pretty mild. That’s not torchy; it’s merely average.

Yes, "mild" relative to average. 

Semantically this feels like standard, boilerplate stuff (PLEASE NOTE: "boilerplate" doesn't literally mean torchy in this case, either. It's a phrase.)

 

[Jesse]

50/35 day here. Mostly sunny much of the afternoon with some light east winds.

It's clouded up and is a little mild for this time of night in December now, still 48. Should be getting some rain showers by midnight.

[luminen]

It's literally been raining here nonstop for 2-3 days at 8-10C. Not fun but that's to be expected here.

No different from every other year in recent memory (besides 16-17).

[Brian_in_Leavenworth]

7 minutes ago, Jesse said:

Average low is about 34-35 for December down here, so lows around 40 represent a +5 or +6 departure, which is pretty torchy. This stuff isn't rocket science.

But if you had clear weather, and an average high temp for the day, the morning lows would be below normal.   So would that mean you would be in the ice bucket?  Warm mornings in this case is not a function of a real warm air mass otherwise the daily highs would be really warm too.  It is simply a function of cloud cover.   In both scenarios, you could either be warmer than normal or colder than normal simply based on whether or not there are clouds.  That is not rocket science either.

Last week before clouds rolled in we had normal daytime highs in the mid to maybe upper 30's, but clear skies dropped our temps into the upper teens, which is below normal.  Overall below normal temps.  But I wouldn't say we were having arctic weather but according to all of your definitions, we were.

So Western Washington was torching and I was in the ice bucket.  OK.  I will enjoy the torching coming up as I watch the snow pile up at my house next week.  

 

[BLI snowman]

1 minute ago, Brian_in_Leavenworth said:

But if you had clear weather, and an average high temp for the day, the morning lows would be below normal.   So would that mean you would be in the ice bucket?  Warm mornings in this case is not a function of a real warm air mass otherwise the daily highs would be really warm too.  It is simply a function of cloud cover.   In both scenarios, you could either be warmer than normal or colder than normal simply based on whether or not there are clouds.  That is not rocket science either.

Last week before clouds rolled in we had normal daytime highs in the mid to maybe upper 30's, but clear skies dropped our temps into the upper teens, which is below normal.  Overall below normal temps.  But I wouldn't say we were having arctic weather but according to all of your definitions, we were.

So Western Washington was torching and I was in the ice bucket.  OK.  I will enjoy the torching coming up as I watch the snow pile up at my house next week.  

 

Yeah... I mean you live in a totally different climate zone. That isn't exactly a revelation, nor is the fact that significant warmth here in the winter is often a function of cloudcover and onshore flow rather than a singularly accurate reflection of the upper level airmasses themselves. We are very reliant upon offshore flow or dead gradients for cold departures here in the winter, and the past week has had way too much mixing here to allow for that with the weak systems that broke through the ridge on the westside.

 

[Jesse]

14 minutes ago, Brian_in_Leavenworth said:

But if you had clear weather, and an average high temp for the day, the morning lows would be below normal.   So would that mean you would be in the ice bucket?  Warm mornings in this case is not a function of a real warm air mass otherwise the daily highs would be really warm too.  It is simply a function of cloud cover.   In both scenarios, you could either be warmer than normal or colder than normal simply based on whether or not there are clouds.  That is not rocket science either.

Last week before clouds rolled in we had normal daytime highs in the mid to maybe upper 30's, but clear skies dropped our temps into the upper teens, which is below normal.  Overall below normal temps.  But I wouldn't say we were having arctic weather but according to all of your definitions, we were.

So Western Washington was torching and I was in the ice bucket.  OK.  I will enjoy the torching coming up as I watch the snow pile up at my house next week.  

 

You make some good points here. All I was saying is that even though we generally have "mild" winters around here it doesn't mean we can't be milder than average. It was a response to his stand alone post and not really relating to the discussion that you were involved in beforehand.

[SilverFallsAndrew]

The pattern shown on the 18z is pretty mild for NW Oregon. Several days on that run look like mid 50s in the Willamette Valley at face value. 

[Jesse]

Just now, SilverFallsAndrew said:

The pattern shown on the 18z is pretty mild for NW Oregon. Several days on that run look like mid 50s in the Willamette Valley at face value. 

Cooler than Eugene was today. Baby steps!

[umadbro]

1 minute ago, SilverFallsAndrew said:

The pattern shown on the 18z is pretty mild for NW Oregon. Several days on that run look like mid 50s in the Willamette Valley at face value. 

Only some people allow these posts. If Tim does it, he's the worst person in the world.

[SilverFallsAndrew]

The record high of 68 at SLE from 1929 for today is obviously bogus, but the NWS recognizes it, but they won’t recognize the -12 readings EUG and SLE put up on the same day in 1972. 

[Gradient Keeper]

00z GFS Day 1

[Gradient Keeper]

Day 2

[Gradient Keeper]

Day 3

[SilverFallsAndrew]

Dec 1972.pdf

[Gradient Keeper]

2 minutes ago, SilverFallsAndrew said:

Dec 1972.pdf 6.57 kB · 3 downloads

Jeez. Bitter cold to torching within 1 week. NOPE!

[Gradient Keeper]

Day 4 Trough looking a bit more consolidated

[SilverFallsAndrew]

1 minute ago, DJ Droppin said:

Jeez. Bitter cold to torching within 1 week. NOPE!

Lotsa snow with that whole event though.