December 2020 Weather Observations for the PNW

[BLI snowman]

52 minutes ago, TT-SEA said:

Not likely given the duration of the precip.   The main band is through here by 8 p.m. and the ECMWF insists the c-zone will be up north later in the night and it never really shifts south... it just fades away by morning.   The ECMWF does really well with c-zone placement.

 

 

Temps will likely climb most places tonight too once the precip rates diminish, given the fairly weak CAA taking place. May be a rain to snow back to rain situation for a lot of folks.

[FroYoBro]

Just now, BLI snowman said:

Temps will likely climb most places tonight too once the precip rates diminish, given the fairly weak CAA taking place. May be a rain to snow back to rain situation for a lot of folks.

Yeah, I am surprised this hasn't been mentioned yet on here. Not exactly a flash freeze scenario. I'm sure people will be happy just to see flakes though. 

[Blizzard777]

Looks perfect !

28*

[Blizzard777]

Just now, 1000'NorthBend said:

I've got my table cleared and ruler ready. I don't care if I only end up measuring 1/2" of accumulation, I'm measuring something tonight and I'll post it here!

[TT-SEA]

Just now, 1000'NorthBend said:

I've got my table cleared and ruler ready. I don't care if I only end up measuring 1/2" of accumulation, I'm measuring something tonight and I'll post it here!

I think we will have more than 1/2"... we always seem to score in these set ups.   I am guessing 3-4 inches by morning. 

[TT-SEA]

And its up to 60 degrees now in North Bend... we will put the "warm ground" theory to the test tonight because it does not get much warmer than this in December.

 

[Rubus Leucodermis]

3 minutes ago, TT-SEA said:

And its up to 60 degrees now in North Bend... we will put the "warm ground" theory to the test tonight because it does not get much warmer than this in December.

 

If it does stick, please post pictures of the snow on your banana plants.

[Kayla]

2 minutes ago, TT-SEA said:

And its up to 60 degrees now in North Bend... we will put the "warm ground" theory to the test tonight because it does not get much warmer than this in December.

 

I'm going to go out on a limb to say that you'll likely see 2-4" tonight but by morning most of it will be gone.

[Rubus Leucodermis]

From the current AFD. Looks like the professionals are relying on the GOLU model today!

Quote

All of this means there is a threat of lowland snow later today. As usual, pinning down the details is very tricky and uncertainty is high. Ensembles are sending a strong signal that there is at least a chance of snow for the interior lowlands, mainly from Tacoma north. However, there isn`t any cold air in place and the ground is not cold so it will be hard for accumulations to develop on the roads. We probably won`t really know how this will all shake out until the event is underway [emphasis added]. For now the main messaging will be possible snow for the lowlands later today but minimal accumulations and impacts. That could change of course. Stay tuned.

 

[TT-SEA]

6 minutes ago, Kayla said:

I'm going to go out on a limb to say that you'll likely see 2-4" tonight but by morning most of it will be gone.

It usually does not work that way here... not sure why.   Our snow usually sticks around until we have southerly winds and rain and that won't happen again until maybe this weekend.   I bet North Bend will also see snow but in the valley it will melt quickly but not up here.

[Kayla]

5 minutes ago, TT-SEA said:

It usually does not work that way here... not sure why.   Our snow usually sticks around until we have southerly winds and rain and that won't happen again until maybe this weekend.   I bet North Bend will also see snow but in the valley will melt quickly but not up here.

It's looking more and more like a precip driven event to me so as soon as those precip rates drop off you'll see temps rise above 35-36F. Coupled with extremely warm ground and high humidity you're going to see a quick melt off before it gets cold tomorrow night.

At least that's how I see it. Would love to be wrong though, at least for your kiddo!

[TT-SEA]

Just now, Kayla said:

It's looking more and more like a precip driven event to me so as soon as those precip rates drop up you'll see temps rise above 35-36F. Coupled with extremely warm ground and high humidity you're going to see a quick melt off before it gets cold tomorrow night.

Maybe... I will post pics in the morning!

[luminen]

How is Portland sitting at 13C?

Ridiculous warmth.

[BLI snowman]

Just now, Kayla said:

It's looking more and more like a precip driven event to me so as soon as those precip rates drop up you'll see temps rise above 35-36F. Coupled with extremely warm ground and high humidity you're going to see a quick melt off before it gets cold tomorrow night.

Yeah, mixing should commence quickly as soon as the main band exits. -4c at 850mb with westerly flow ain't gonna get it done for cold temps tonight.

[BLI snowman]

12z is kinda cold again.

[Rubus Leucodermis]

3 minutes ago, luminen said:

How is Portland sitting at 13C?

Ridiculous warmth.

Note the position of the incoming low on the surface analysis:

PDX is squarely on the warm side of it. The boundary seems to be in the Tacoma area. From the 0800 observations:

CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS
 EVERETT        LGT RAIN  43  41  93 S3        29.75F                  
 BOEING FIELD   RAIN      44  43  96 SE5       29.75F FOG              
 RENTON         LGT RAIN  45  43  93 NW5       29.75F                  
 SEATAC AIRPORT LGT RAIN  44  43  96 NW5       29.74F FOG              
 JBLM-MCCHORD   CLOUDY    46  45  96 S8        29.74F                  
 PUYALLUP       CLOUDY    55  54  94 S8G18     29.76F                  
 BREMERTON      LGT RAIN  41  41 100 CALM      29.74F FOG              
 JBLM-FT LEWIS  CLOUDY    54  54 100 SE16G24   29.73F                  
 TACOMA NARROWS LGT RAIN  42  41  96 VRB6      29.75F VSB 1/2          

[MR.SNOWMIZER]

I guess it's time to start looking past day 7. Been much less stressful not looking in the clown range!!

[Blizzard777]

On another note the Christmas Star main event is tonight!  Hrrr says I have a chance gfs says no deal 

[kokaneekidz]

Dumping in Port Alberni

 

[Blizzard777]

3 minutes ago, MR.SNOWMIZER said:

I guess it's time to start looking past day 7. Been much less stressful not looking in the clown range!!

New Year’s ice storm  ,ok not quite New Years 

[Phil]

34 minutes ago, hawkstwelve said:

HRRR looks to have finally stopped smoking the good stuff and has come back down to Earth for snow totals.

HRRR over-did accumulations here last week as well. Was forecasting 6-8”, but we ended up with 2” with sleet/ZR mixed in.

[Rubus Leucodermis]

Positive splat test.

[Skagit Weather]

Update from earlier: rain shadow has returned! 0.73" on the day, 3.10" on the month, 39.10" on the year.

Currently sitting at my 5th wettest year since 2008, but have a chance to surpass every year except 2012 where I had almost 44".

[kokaneekidz]

Just now, Rubus Leucodermis said:

Positive splat test.

Are you towards Lake Samish or northwest of Bellingham>? Like Slater Road?

[kokaneekidz]

Weather Canada was forecasting a change to snow around noontime so it is hours ahead of their projections for Greater Victoria and environs area

[VancouverIslandSouth]

Mixed rain/snow here in Victoria, temperature has been steadily falling and is now around 34.5F. Just a little north of here it's already switched to snow with snow accumulating on the road in many places up the east side of the island.

[Blizzard777]

Duncan BC

34*

elevation 66’

[Blizzard777]

South winds around 5 mph now

49*  rain 

 

[VancouverIslandSouth]

Snowy up around Shawnigan:

Also around Nanaimo:

[Christensen87]

Warm January according to CFS 

[kokaneekidz]

I notice the winds have switched all southerly in the Puget Sound area except for Bellingham now.

[Rubus Leucodermis]

21 minutes ago, kokaneekidz said:

Are you towards Lake Samish or northwest of Bellingham>? Like Slater Road?

Cordata, about a mile north of the mall.

[kokaneekidz]

2 minutes ago, Rubus Leucodermis said:

Cordata, about a mile north of the mall.

Nice so that is about 200' elevation? Looking forward to pics of snow accumulating in your neck of the woods soon *****************

I noticed the NE wind is stiff at Bellingham Intl Airport this last hour

[Esquimalt]

10 minutes ago, VancouverIslandSouth said:

Snowy up around Shawnigan:

Also around Nanaimo:

I think we’ll see a Transition to Big wet flakes but I don’t believe the latest HRRR with 7 inches lol

[Ray]

Up to a shocking 57 degrees now from a 5am low of 46.  Normally I do pretty good for snow where I'm at.  Not thinking that will be the case this time around.

[Rubus Leucodermis]

38˚F chunky rain.

[T-Town]

Went from 46 to 53 here over the last 45 minutes or so. 

[VancouverIslandSouth]

10 minutes ago, Esquimalt said:

I think we’ll see a Transition to Big wet flakes but I don’t believe the latest HRRR with 7 inches lol

There must be a warm layer aloft, it's currently 1.0C here (33.8F) but there seems to be less mixing now than there was earlier. Just hit an inch of rain on the day. Once we kick that warm layer it should be a fast transition to all snow.

[Esquimalt]

3 minutes ago, VancouverIslandSouth said:

There must be a warm layer aloft, it's currently 1.0C here (33.8F) but there seems to be less mixing now than there was earlier. Just hit an inch of rain on the day. Once we kick that warm layer it should be a fast transition to all snow.

Yeah rain here too.  Euro looks better for us but I really don’t see there being 5 inches of accumulation here come tonight.  Almost a foot at the ferries according to the euro 

[Jesse]

Up to 59 at PDX this morning. Yuck for the winter solstice. Hopefully they don't hit 60.