December 2020 Weather Observations for the PNW

[Blizzard777]

11 minutes ago, hawkstwelve said:

And finally through 1AM... This is just a sliver more than the 06z showed.

 

Streetlamp date tonight 

 

53*

[SouthHillFrosty]

[VancouverIslandSouth]

8 minutes ago, Esquimalt said:

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 

Yeah, we're not going to see those 10:1 ratios. It's transitioned over to snow up around Sydney so perhaps favorable upper level conditions are close. Down to 0.9C (33.6F) here now, but still mostly rain.

[Blizzard777]

Thetis Island looks sweet  34* as well 

 

[Front Ranger]

1 hour 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.

 

Assuming you are referring to warm ground slowing down accumulation, as someone who frequently sees snowstorms that follow 60+ days, I can tell you the warm ground theory is only true for maybe the first hour or two of snow falling. At least if you're seeing moderate to heavy snow.

 

[North_County]

Heavy chunky rain and positive splats for the past couple of hours here. This appears to be a bit ahead for schedule, so hopefully that's good news for later in the day.

 

Changeover from straight rain to rain/snow mix was right at the southern edge of town, which seems to happen a lot. Straight rain in Lynden as of about 9:30am.

[VancouverIslandSouth]

7 minutes ago, Jginmartini said:

Thetis Island looks sweet  34* as well 

 

That area seems to be the real winner with the shift north, still mostly rain here.

[SouthHillFrosty]

3 minutes ago, hawkstwelve said:

The GFS v16 shows over a foot of snow near Everett. 

Good to know the replacement GFS can be just as loony as the old version. Real big upgrade.

Hey it stills works perfectly fine south of King County. Zero snow from Tacoma to Eugene

[MossMan]

Here is my “before” picture...The “after” picture will probably look identical haha! 
Up to 45 degrees with moderate drizzle.

.81” so far on the day, 5.10” for the month. 

[SouthHillFrosty]

Just now, hawkstwelve said:

12z Euro shows the big temperature change for Central Sound areas to occur between 4-5PM. Surface temps, 925s, and 850s are all shown to drop off around that time. If we are going to get any snow, it'll be around that time or later. 

There is a South Sound CZ signature showing up between 7-8PM. Probably the best chance for any surprises.

LETS GO BABY. I might get a rain snow mix out of this!!!!!! Real talk tho, it's been awhile since my area has had a convergence zone for snow

[kokaneekidz]

Now the sun is shining! What a fools errand trying to forecast this mess today. Might be the calm before a foot of snow LMAO

[mtep]

Got some nice chunky rain a few minutes ago. Gonna drive up to the shmancy neighborhood up the hill at 800' and see what the story is up there. 

[wxmet]

6 minutes ago, hawkstwelve said:

12z Euro shows the big temperature change for Central Sound areas to occur between 4-5PM. Surface temps, 925s, and 850s are all shown to drop off around that time. If we are going to get any snow, it'll be around that time or later. 

There is a South/Central Sound CZ signature showing up between 7-8PM. Probably the best chance for any surprises.

Should be fun to count the two flakes that will fall from the sky

[Deweydog]

30 minutes ago, Jesse said:

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

Ironically, this could end up being PDX’s warmest winter solstice since 1972.

[TT-SEA]

61 now and dry... pretty crazy that it will be snowing in 8 hours.

 

[Blizzard777]

15 minutes ago, VancouverIslandSouth said:

That area seems to be the real winner with the shift north, still mostly rain here.

Heavy precipitation band doing its thing 

[Deweydog]

18 minutes ago, Front Ranger said:

Assuming you are referring to warm ground slowing down accumulation, as someone who frequently sees snowstorms that follow 60+ days, I can tell you the warm ground theory is only true for maybe the first hour or two of snow falling. At least if you're seeing moderate to heavy snow.

 

The warm ground thing has never made much sense to me.  Ambient temperature/dew point, precip rates and solar radiation are the only REAL factors.

[TT-SEA]

The main action for King County is between 6 - 9 p.m. 

[Jesse]

3 minutes ago, Deweydog said:

Ironically, this could end up being PDX’s warmest winter solstice since 1972.

Interestingly it looks like they are the warmest spot in the I-5 corridor right now. SEA is only 49.

[Cloud]

Temps have really gone up now around the region as the south wind cranked up. It's gone a good +5F in past hour or so with a strong S wind at SEA. I think it's forecast to go up to 56F or 57F by 2PM today then it drops like a roller coaster. 

[Phil]

22 minutes ago, Front Ranger said:

Assuming you are referring to warm ground slowing down accumulation, as someone who frequently sees snowstorms that follow 60+ days, I can tell you the warm ground theory is only true for maybe the first hour or two of snow falling. At least if you're seeing moderate to heavy snow.

 

This. Once it snowed an inch 18hrs after a 74°F high. In the middle of the day in March.

Sun angles and ground temps matter. But only in marginal setups. And even then it can be overcome by rates.

[Art_Digbee]

Blew past 1" of rain here, up to 1.1+" now and finally cooling again. 38.2 with a heavy precip band coming through!

[Deweydog]

5 minutes ago, Jesse said:

Interestingly it looks like they are the warmest spot in the I-5 corridor right now. SEA is only 49.

They’re just trying to keep up with Troutdale and failing so far.

[Rubus Leucodermis]

37˚F rain.

[wxmet]

Feels like the CZ should setup further north than what the ECMWF is showing but that model can’t be wrong inside 24hrs.

[Chewbacca Defense]

Positive splat tests I-5 and Birch Bay Lynden rd.  Starting to see it switch from slushy rain to wet snowflakes (if that makes sense) as I’m typing this.

[MossMan]

2 minutes ago, Rubus Leucodermis said:

37˚F rain.

Up to 46 here now! 

[TT-SEA]

1 minute ago, wxmet said:

Feels like the CZ should setup further north than what the ECMWF is showing but that model can’t be wrong inside 24hrs.

Initially there will be multiple c-zones right after the main frontal passage.   Later tonight it shows a single c-zone from Randy's area eastward and that fades away by early morning rather than moving south.

[SouthHillFrosty]

Special Weather Statement!!!! 

 

...PERIODS OF MODERATE TO HEAVY RAINFALL LATE TONIGHT THROUGH MONDAY WILL YIELD AN INCREASED THREAT OF LANDSLIDES IN WESTERN WASHINGTON...

[MossMan]

Very heavy drizzle now! Temp at 46.0 however it appears that the wind is attempting to shift to a W-NW direction. 
Up to .86” on the day. 

[wxmet]

Lots of rain everywhere.

[Blizzard777]

Wind approaching 20 mph , 54* and raining pretty good.

Time for a little walk in the storm by the Sound.  

[VancouverIslandSouth]

15 minutes ago, Jginmartini said:

Heavy precipitation band doing its thing 

Snowing up around Victoria airport now (15 miles north of here), agonizingly close, but still 33.4F rain here (someone needs to give that warm air aloft a nudge, it's overstayed its welcome).

[FroYoBro]

Up to 59 here with sunbreaks and a warm breeze. Feels bizarre out. 

[North_County]

Still wet, but much more snow-like now.

[SouthHillFrosty]

https://www.sfu.ca/itservices/technical/webcams/webcams_terryfoxfield.html

Check out the heavy snow

[MossMan]

2 minutes ago, North_County said:

Still wet, but much more snow-like now.

I want to see an after video, I think you are going to get nailed! 

[luminen]

Snowing here now.

Take that Jesse. 

[Skagit Weather]

Light rain and 40F here. It looks like the warmth has reached Arlington and Coupeville just about 20 miles south. I don't think it's supposed to get up here, but we'll see.

[Esquimalt]

4 minutes ago, hawkstwelve said:

At the 11AM update, 925s are around 8c and 850s are sitting at about 4c.

Both numbers are just a little chillier than the 12z Euro showed around this time.

What are the 925s and 850s for Vic compared to the euro?