January 2024 Weather in the PNW (Part II)

[AbbyJr]

9 hours ago, Phil said:

Look at the anomalies associated with the current block versus the one in 1968. This year’s block is stronger, ironically.

There’s a lot more going on here than the strength of GOA block, if you’re looking for why 1968 evolved differently.

It's just frustrating to waste an off the charts -NAO simply because the North Pacific won't cooperate. This could have turned out a lot better than it likely will if there was less energy forcing a progressive pattern. Models unfortunately failed in the 7 day range. But Phil, I do remember you warning us that we were going to enter a volatile pattern that is subject to a last minute rug pull. While I wouldn't consider this one last minute, I will say failing this bad in the 150+ hour range is rather disappointing, especially from the Euro. But at least we have some winter to enjoy and maybe we will get lucky and pull off a full wind reversal. Though that may just send more cold east. I don't know.

[Snownerd3000]

3 hours ago, TT-SEA said:

18Z ECMWF shows lows 40s in Seattle at that time. 

 

Throw it out! Obviously garbage

[Ken in Wood Village]

I really like how the NWS worded this for the low coming in on Tuesday night and Wednesday morning. 

 

The biggest change we made was earlier in the shift, introducing snow
potential to the lowlands Tuesday night into Wednesday. Guidance
began to hint at this possibility 24-36 hours ago as they latched on
to a shortwave emerging off Japan. This system will be whisked across
the Pacific by a strong and zonal jet stream, making landfall
somewhere in the Pac NW Tuesday night. Given the fast flow pattern
and subtle features involved, uncertainty on where this landfall will
occur is high and unfortunately this landfall location is immensely
important to the forecast. Colder air to the north of the low`s track
will lead to much lower snow levels than to its south. This system
will have abundant moisture involved, as the Scripps Center for
Western Weather and Water Extremes (CW3E) guidance suggests a weak
atmospheric river is in play as the system moves onshore. Forcing
will be impressive as post-frontal cold air pushes back against the
mild Pacific air the low is trying to bring onshore, enhancing
frontogenesis, especially at the surface. Given the forcing and
moisture involved with this system, whoever ends up getting snow from
this system could potentially see a lot of it.

[Rubus Leucodermis]

39 minutes ago, MossMan said:

OMG!!! 

I'm in the blue!

[Cascadia_Wx]

Who’s jover?

[MR.SNOWMIZER]

So far on the 00z models the northern trend has stopped. Hopefully gfs and Euro follow this idea.

 

[Cold Snap]

The fact the stingy ICON shows this for the Portland area makes me have a good feeling about down there tomorrow night.

[Prairiedog]

Southerlies have picked up.  Temp bounce from 42f to 48f

[Jbolin]

6 minutes ago, Ken in Wood Village said:

I really like how the NWS worded this for the low coming in on Tuesday night and Wednesday morning. 

 

The biggest change we made was earlier in the shift, introducing snow
potential to the lowlands Tuesday night into Wednesday. Guidance
began to hint at this possibility 24-36 hours ago as they latched on
to a shortwave emerging off Japan. This system will be whisked across
the Pacific by a strong and zonal jet stream, making landfall
somewhere in the Pac NW Tuesday night. Given the fast flow pattern
and subtle features involved, uncertainty on where this landfall will
occur is high and unfortunately this landfall location is immensely
important to the forecast. Colder air to the north of the low`s track
will lead to much lower snow levels than to its south. This system
will have abundant moisture involved, as the Scripps Center for
Western Weather and Water Extremes (CW3E) guidance suggests a weak
atmospheric river is in play as the system moves onshore. Forcing
will be impressive as post-frontal cold air pushes back against the
mild Pacific air the low is trying to bring onshore, enhancing
frontogenesis, especially at the surface. Given the forcing and
moisture involved with this system, whoever ends up getting snow from
this system could potentially see a lot of it. 

What WFO posted that?

[Ken in Wood Village]

It's the Portland NWS that posted it this afternoon. Here is another part of their forecast decision.

 

Models have been honing in on somewhere along the north Oregon coast
as the landfall location Tuesday night. With 850 mb temperatures in
the -3 to -5 deg C range and fairly strong S-SW flow ahead of the
low, conditions look marginal at best for snow levels to reach the
valley floors, even on the colder north side of the system. That
said, this system is highly dynamic and has the potential to produce
heavy enough precipitation to drag snow levels lower than they
otherwise would be, largely due to evaporational cooling and the
latent heat absorption by melting snowflakes aloft. If this lasts
long enough - and the latest NAM soundings suggest it will - rain may
change to wet snow across the Portland/Vancouver metro Tuesday
night... with the better chance being in the northern Clark County
suburbs like Battle Ground and Yacolt. That said, if the low tracks
farther south, these chances also shift south. At this point, it
appears there will be a 20-40 mile wide stripe where rain changes to
snow down to the lowest elevations Tuesday night into Wednesday
morning, with up to a slushy inch or two of snow for the valley
floors and perhaps up to as much as 3-6 inches above 1000 feet. The
12z HREF supports this with a 20-40% chance of any accumulating snow
for the lowlands Albany northward, and as much as a 20% chance of 4
or more inches of snow across a few swaths of the valley. This likely
represents a handful of 12z HREF members that have this stripe of
lowland snow, but have it in different locations. So this adds
confidence to the potential for snow at least down to 500-1000 feet
for at least a portion of the lowlands. The problem is that we don`t
really know where this stripe will be at this point - this forecast
will become refined as more HREF members make it into the mix.

[Frontal Snowsquall]

18 minutes ago, Doinko said:

ICON takes a good track for PDX

00z ICON takes the Friday afternoon system further south.

 

[Doinko]

ICON is coming in farther south, It's going to be snowy for PDX

[Prairiedog]

1 hour ago, RaleighHillsRunner said:

Mark is the GOAT for PDX snowstorms - sure he’s had his misses and years when models simply whiffed completely, but I pretty much take his analysis in a dynamic/uncertain scenario as gospel at this point. Think he’s also more a hedger these days but we’ll see how it plays out.

Not so much hedging but rather patient.  He is hard fast :  7-10 days:  Pattern Reconition.  Something interesting could be on the way.  5--7 days Trending up or down.  Will it be cold enough?  Moisture?  3-5 days is about timing and intensity.  (becoming likely).  1-3 days out , forecast details.  Amts and location.  He's posted this before.  Those are his parameters. 

[Doinko]

Just now, Frontal Snowsquall said:

00z ICON takes the Friday afternoon system further south.

 

Temps drop below friday night and then a big slug of moisture, looks like a big ice storm for the Valley as well

[LowerGarfield]

Temperature is starting to rise but still accumulating. Our back door light went on with a strong squall passing through. I'm certain I've reached a half inch but I'm waiting to check until the very last minute. 

[Frontal Snowsquall]

00z ICON takes the system right behind it along the same track. 

[lowlandsnow]

Nice west shift on the ICON too the trend is our friend

[AbbyJr]

7 hours ago, Phil said:

The Euro has legit SSW D10, but the GFS is less enthusiastic.

Could that give the PNW another chance of more winter weather or would the cold just go east?

[Doinko]

1 minute ago, Frontal Snowsquall said:

00z ICON takes the system right behind it along the same track. 

Major icing for the Willamette Valley, and big snow here

[Sandy rocks]

I am curious why it is that Prairie Dog has a temperature of 48 when it is 39 here in Sandy. I don't think the temperature got over 41 today. Although this does illustrate the discrepancy between the two locations.

[Cascadia_Wx]

Would love to see the GFS stop with the horrible trends tonight. At least pause or even improve a little.

[Doinko]

Huge stream of moisture pointed right at Oregon

[snow_wizard]

The ICON is sending cold air further offshore along the BC coast than the 18z.  Might be a good run.

[MR.SNOWMIZER]

5 minutes ago, Doinko said:

ICON is coming in farther south, It's going to be snowy for PDX

It's further south than the 18z but north of the 12z. I always compare 12z and 00z and 06z and 18z looking for trends.

[TacomaWx]

1 minute ago, Cascadia_Wx said:

Would love to see the GFS stop with the horrible trends tonight. At least pause or even improve a little.

I think it will atleast stop moving north. I really don’t think this is just going to be a 49th parallel north exclusive event. 

[Doinko]

Still cold Sunday morning after the storm, doesn't fully warm up

[Roman-Dallas Snow-Zone]

who's ready for 12-24" of heavy wet snow. It was only a few years ago east Eugene up into Oakridge got hammered with heavy wet snow and the tree damage was very similar to ZR storm. 

[Cold Snap]

Just now, TacomaWx said:

I think it will atleast stop moving north. I really don’t think this is just going to be a 49th parallel north exclusive event. 

What the GFS is showing but more south would be really nice. Kind of the Feb 2021 where the first storm gave Olympia south to Portland some snow and the second storm giving the Seattle area some snow that way everyone can score.

[Cascadia_Wx]

1 minute ago, Roman-Dallas Snow-Zone said:

who's ready for 12-24" of heavy wet snow. It was only a few years ago east Eugene up into Oakridge got hammered with heavy wet snow and the tree damage was very similar to ZR storm. 

Tigar was vacationing in Tahiti for that one.

[Doinko]

Frigid early next week as well

[Frontal Snowsquall]

4 minutes ago, snow_wizard said:

The ICON is sending cold air further offshore along the BC coast than the 18z.  Might be a good run.

Some snow reaches Puget Sound as the system tracks through Oregon. The entire I-5 corridor from Eugene North are below freezing Saturday afternoon.

 

[Cold Snap]

Just now, Doinko said:

Frigid early next week as well

Nice to see the cold could go for a little while. Hopefully that can open the door to more snow chances.

[Doinko]

Snow totals, nice storm

[Slushy Inch]

50 minutes ago, Cold Snap said:

NAM 3km is showing even some moisture in the sound Wednesday morning.

That’s actually less than 18z

[SnowWillarrive]

Just now, Frontal Snowsquall said:

Some snow reaches Puget Sound as the system tracks through Oregon. The entire I-5 corridor from Eugene North are below freezing Saturday afternoon.

 

Mossman sacrificed his snow for the greater good. 

[MikeInEverett]

1 minute ago, Doinko said:

Snow totals, nice storm

ICON hates Snohomish County!

[Ken in Wood Village]

Mark Nelsen posted a brief post about the low Tuesday night and Wednesday morning on Facebook. 

Watch this video on Facebook

https://fb.watch/psuI-V1ifs/?mibextid=CDWPTG

 

 

[MossMan]

3 minutes ago, Doinko said:

Snow totals, nice storm

Yuck. GO GFS! 

[umadbro]

3 minutes ago, Doinko said:

Snow totals, nice storm

I’ll take 10-15 inches

[Slushy Inch]

Portland buried wrap around snow reaching puget sound