December 2020 Weather Observations for the PNW

[snow_wizard]

2 minutes ago, wxmet said:

NWS:

In regards to the snow potential along the Puget Sound and into
the Cascade Foothills, there is considerable uncertainty. Overall,
the primary concern is the fact that this setup doesn`t suggest
much wintry precipitation in the area, not to mention the lack of
cold air in place with temperatures today through tonight in the
40s to low 50s. Possibly the biggest piece of the puzzle for snow
potential in the Puget Sound will be the extent dynamic cooling
during the heaviest precipitation on Monday afternoon. HRRR, 3K
NAM, and other hires models have a changeover to a brief heavy
thump of snow Monday afternoon across areas of the Puget Sound as
cold air filters in. If this does occur, the primary concerns in
regards to impacts would most likely be a quick reduction in
visibility with a heavy, wet rain/snow mix. The current thinking
regarding any accumulations would be trace amounts on grassy
surfaces (at best) near the water, with less than an inch for the
Cascade Foothills (or snow levels above 700-1000 feet). Timing of
this would be focused on 10AM-2PM north of King County, mainly
late afternoon into the evening south of this area. However, it is
also possible guidance is overdoing the extent of cooling and a
cold rain will be the main focus for most of the area on Monday.
Of course, it is also possible, albeit not expected, that the snow
event plays out as shown on shorter range guidance. The current
thinking though is that significant accumulations aren`t expected
for the Puget Sound area at this time, though monitor the
forecasts through tonight.

 

A really skeptical take considering the good model agreement.  Huge bust potential here.

[MossMan]

3 minutes ago, wxmet said:

NWS:

In regards to the snow potential along the Puget Sound and into
the Cascade Foothills, there is considerable uncertainty. Overall,
the primary concern is the fact that this setup doesn`t suggest
much wintry precipitation in the area, not to mention the lack of
cold air in place with temperatures today through tonight in the
40s to low 50s. Possibly the biggest piece of the puzzle for snow
potential in the Puget Sound will be the extent dynamic cooling
during the heaviest precipitation on Monday afternoon. HRRR, 3K
NAM, and other hires models have a changeover to a brief heavy
thump of snow Monday afternoon across areas of the Puget Sound as
cold air filters in. If this does occur, the primary concerns in
regards to impacts would most likely be a quick reduction in
visibility with a heavy, wet rain/snow mix. The current thinking
regarding any accumulations would be trace amounts on grassy
surfaces (at best) near the water, with less than an inch for the
Cascade Foothills (or snow levels above 700-1000 feet). Timing of
this would be focused on 10AM-2PM north of King County, mainly
late afternoon into the evening south of this area. However, it is
also possible guidance is overdoing the extent of cooling and a
cold rain will be the main focus for most of the area on Monday.
Of course, it is also possible, albeit not expected, that the snow
event plays out as shown on shorter range guidance. The current
thinking though is that significant accumulations aren`t expected
for the Puget Sound area at this time, though monitor the
forecasts through tonight.

 

So I might get slush in my bark beds...Woo Hoo!! 

[Front Ranger]

1 hour ago, wxmet said:

During the event 

True story. Can't blame them for waiting to pull the trigger on this one.

[TT-SEA]

31 minutes ago, MossMan said:

It does? I need to take a look! 
Anyway the damage is done, equipment is staged, and my wife just found out. 

 

In addition to getting the snowblower ready... we just got the shovels and all the sleds down from the attic above the garage.   We are full winter mode now.   My daughter is done with school now for the holidays so she will be sledding from the Tuesday through Christmas Day.     

Looks the rain holds off until after dark on Christmas and that will probably be when the real melting starts here.

[MossMan]

2 minutes ago, TT-SEA said:

 

In addition to getting the snowblower ready... we just got the shovels and all the sleds down from the attic above the garage.   We are full winter mode now.   My daughter is done with school now for the holidays so she will be sledding from the Tuesday through Christmas Day.     

Looks the rain holds off until after dark on Christmas and that will probably be when the real melting starts here.

The sled!! Thanks for the reminder, need to get that out of the garage loft! 

[snow_wizard]

3 minutes ago, TT-SEA said:

 

In addition to getting the snowblower ready... we just got the shovels and all the sleds down from the attic above the garage.   We are full winter mode now.   My daughter is done with school now for the holidays so she will be sledding from the Tuesday through Christmas Day.     

Looks the rain holds off until after dark on Christmas and that will probably be when the real melting starts here.

The NWS says you will get an inch at best. 

[Timmy]

35 minutes ago, MossMan said:

It does? I need to take a look! 
Anyway the damage is done, equipment is staged, and my wife just found out. 

I can still see two of your license numbers

[Jbolin]

I'm not sure I believe any of the models right now, esp the ECMWF, the likelihood of any accumulating snowfall below 800 ft is zilch and I'll be frank, I do not see the central sound getting upwards of 7+ inches in places esp in/around Seatac. 

I just don't see it happening even with modeled precip rates in the baro zone

[mtep]

I'm going to be driving from Bellingham to SeaTac tomorrow at 5. Would be cool to get a tour of the I5 corridor slush from North to South. Thinking cold thoughts

[snow_wizard]

5 minutes ago, Front Ranger said:

True story. Can't blame them for waiting to pull the trigger on this one.

They are apparently forgetting about Nov 2003.  With that one we didn't have as good of a setup as we have this time.  It was 60 early in the evening on the eve of the snow.  I think this one is colder overall and probably higher precip rates.

[Winterdog]

5 minutes ago, MossMan said:

So I might get slush in my bark beds...Woo Hoo!! 

I guess I was off by a few miles on my earlier interpretation of 6”+ but still solidly in the blue.

[Rubus Leucodermis]

From the Canadian forum:

[MossMan]

1 minute ago, Timmy said:

I can still see two of your license numbers

If you can guess all of the other numbers/letters correctly can you go ahead and renew my tabs...Thanks!! 

[Jesse]

3 minutes ago, MossMan said:

If you can guess all of the other numbers/letters correctly can you go ahead and renew my tabs...Thanks!! 

I already got a screen shot before you changed it.

[wxmet]

Just now, Jesse said:

I already got a screen shot before you changed it.

I have his house address.

[TacomaWaWx]

Sounds like cliff mass is on board. 

[VancouverIslandSouth]

8 minutes ago, snow_wizard said:

They are apparently forgetting about Nov 2003.  With that one we didn't have as good of a setup as we have this time.  It was 60 early in the evening on the eve of the snow.  I think this one is colder overall and probably higher precip rates.

This happening with the lowest sun angles of the year certainly doesn't hurt either.

[TacomaWaWx]

54/50 spread so far with 0.02” early this morning. Would really be something to get accumulating snowfall here just after such warm temperatures. 

[jakerepp]

27 minutes ago, snow_wizard said:

Here it is.

 

CZ needs to be 10 miles North

[wxmet]

If a convergence zone develops all bets are off.

[MossMan]

5 minutes ago, wxmet said:

I have his house address.

Perfect! Could you bring your big extension ladder and clean my high gutters when you stop by...Thanks! 

[TacomaWaWx]

5 minutes ago, jakerepp said:

CZ needs to be 10 miles North

Lol for you maybe! For south hill frosty..Jim, puyallupjon and me this is perfect! Convergence zones usually don’t end up this far south...I’d bet on it being north of this location tbh. 

[jakerepp]

2 minutes ago, TacomaWaWx said:

Lol for you maybe! For south hill frosty..Jim, puyallupjon and me this is perfect! Convergence zones usually don’t end up this far south...I’d bet on it being north of this location tbh. 

Yeah, I would honestly assume so as well. I-90 ain’t exactly the sweet spot. I’ve lived in the southern reaches of Snohomish county since 2005 (Monroe and now Edmonds) and have always gotten the benefit of good C-Zones.

[Front Ranger]

11 minutes ago, wxmet said:

I have his house address.

I have his SSN if anyone wants it.

[wxmet]

1 minute ago, Front Ranger said:

I have his SSN if anyone wants it.

I’ll give you my routing and account number so you can start a wire transfer.

[jakerepp]

Just now, wxmet said:

I’ll give you my routing and account number so you can start a wire transfer.

I think I know his mother’s maiden name, in case there is a security question. 

[TacomaWaWx]

2 minutes ago, jakerepp said:

Yeah, I would honestly assume so as well. I-90 ain’t exactly the sweet spot. I’ve lived in the southern reaches of Snohomish county since 2005 (Monroe and now Edmonds) and have always gotten the benefit of good C-Zones.

Every now and then we get a convergence zone down this way...but maybe once or twice a year at best. Can’t remember a time where we had convergence zone snowfall either. Either way someone will get some interesting weather tomorrow. 

[MossMan]

Cliff Mass is way more on board than NWS. I need to check in with JAYA’s Twitter to see if he is still NOT on board. 

[Front Ranger]

9 minutes ago, wxmet said:

If a convergence zone develops all bets are off.

Seems pretty likely with this setup.

[Esquimalt]

How’s the 18Z euro looking folks?

[wxmet]

Just now, Esquimalt said:

How’s the 18Z euro looking folks?

Probably bad if no one has posted it yet.

[MossMan]

2 minutes ago, hawkstwelve said:

 

Argh wish I knew how my area fared back then. 

[Bryant]

11 minutes ago, Front Ranger said:

I have his SSN if anyone wants it.

I have his wife if anyone wants her. 

 

Okay too far, my bad

[Fircrest]

15 minutes ago, TacomaWaWx said:

Lol for you maybe! For south hill frosty..Jim, puyallupjon and me this is perfect! Convergence zones usually don’t end up this far south...I’d bet on it being north of this location tbh. 

Good for me too! I'd be surprised it that really happens though...

[TacomaWaWx]

1 minute ago, Fircrest said:

Good for me too! I'd be surprised it that really happens though...

Yea I’d like to see what areas got snow during the 1974 event. Looks like it was central/south sound so maybe it wouldn’t be unprecedented if it occurred tomorrow. I think we’re just too close to the water even at our elevation. Slushy inch of snow is probably the best case scenario in our area. 

[wxmet]

Can’t remember of the top of by head, when was the last time the ECMWF failed a snow forecast?

[Fircrest]

Just now, TacomaWaWx said:

Yea I’d like to see what areas got snow during the 1974 event. Looks like it was central/south sound so maybe it wouldn’t be unprecedented if it occurred tomorrow. I think we’re just too close to the water even at our elevation. Slushy inch of snow is probably the best case scenario in our area. 

That would be fun too.  Just seeing some snow falling would be great for Christmas week!

[jakerepp]

8 minutes ago, hawkstwelve said:

A little less than 12z...

Good thing the Euro is the worst model...right?

[SouthHillFrosty]

2 minutes ago, TacomaWaWx said:

Yea I’d like to see what areas got snow during the 1974 event. Looks like it was central/south sound so maybe it wouldn’t be unprecedented if it occurred tomorrow. I think we’re just too close to the water even at our elevation. Slushy inch of snow is probably the best case scenario in our area. 

SeaTac got 8.8 inches I think. JAYA says the storm looks very similar to that storm

[The Swamp]

convergence zones rarely set up over Puyallup.  they may set up to the north and move from north to south before petering out though.  something stinks about this set up.  again, it looks like someone's 4 year old got a hold of some gray, blue and pink crayons and just went to town.