December 2025 Forecasts and Discussions

[Typeing3]

#LateDecember

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[Typeing3]

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[Catnip]

#LateDecember



gfs_mslp_pcpn_frzn_nwus_fh306-330.gif

Would be nice if that timing sticks….

[Typeing3]

00z HRDPS
12am tomorrow to 12am Thursday

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[Catnip]

What’s your confidence level at for this Typer?

[Catnip]

Lots of cold air in the West on the GEM.

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[Typeing3]

What’s your confidence level at for this Typer?

Very likely the mountains will finally do well, and we may see some snow down to sea level as a more typical La Nina pattern begins to set up over North America. A major cold snap/arctic blast into the South Coast/PNW doesn't seem too likely... at this point, anyways. Won't take too much of a shift for some of that brutally cold air to our north to bleed south towards us, though it looks like we'll mainly stay on the periphery with a few marginal snowfall chances down to sea level.


IMO for the late Dec/early Jan (Dec 20-Jan 10) period:

>90% for zonal/cold onshore flow (major snows >800m)
70% for minor snows down to sea level (<15cm @ YVR)
50% for major snows down to sea level (>15cm @ YVR)
30% for a major cold snap/arctic blast (<-10c @ YVR)

[Catnip]

Very likely the mountains will finally do well, and we may see some snow down to sea level as a more typical La Nina pattern begins to set up over North America. A major cold snap/arctic blast into the South Coast/PNW doesn't seem too likely... at this point, anyways. Won't take too much of a shift for some of that brutally cold air to our north to bleed south towards us, though it looks like we'll mainly stay on the periphery with a few marginal snowfall chances down to sea level.


IMO for the late Dec/early Jan (Dec 20-Jan 10) period:

>90% for zonal/cold onshore flow (major snows >800m)
70% for minor snows down to sea level (<15cm @ YVR)
50% for major snows down to sea level (>15cm @ YVR)
30% for a major cold snap/arctic blast (<-10c @ YVR)

Thank you for that.

Guess we don’t want it really cold as that could leave us high and dry in the snow department.

[Typeing3]

Thank you for that.

Guess we don’t want it really cold as that could leave us high and dry in the snow department.

Yeah, a cold pattern is more stable, but for the big snows you want to be in a high risk/high reward type setup.

Mentioned this yesterday as well but that sharp temp contrast in the west being a reoccurring theme (beginning this week) for what looks like at least another two weeks will lead to significant snows for whichever regions are riding that boundary. That map of the 00z GEM you posted an hour ago is a good illustration of this.

This weekend that line will set up between Prince Rupert/Bella Coola on the coast, east to Terrace/Kitimat, further inland to Williams Lake/100 Mile House and southeast to Revelstoke/Fernie. Forecasts for these regions look very snowy!

Shift that boundary south by a few hundred kilometres and that could be the South Coast during Christmas week... recent examples of this pattern for us locally would be January 2012, February 2017, January 2020, or December 2022. As of now, that's all shifted to the north hence the mild rains around here.

[Storm]

Yeah, a cold pattern is more stable, but for the big snows you want to be in a high risk/high reward type setup.

Mentioned this yesterday as well but that sharp temp contrast in the west being a reoccurring theme (beginning this week) for what looks like at least another two weeks will lead to significant snows for whichever regions are riding that boundary. That map of the 00z GEM you posted an hour ago is a good illustration of this.

This weekend that line will set up between Prince Rupert/Bella Coola on the coast, east to Terrace/Kitimat, further inland to Williams Lake/100 Mile House and southeast to Revelstoke/Fernie. Forecasts for these regions look very snowy!

Shift that boundary south by a few hundred kilometres and that could be the South Coast during Christmas week... recent examples of this pattern for us locally would be January 2012, February 2017, January 2020, or December 2022. As of now, that's all shifted to the north hence the mild rains around here.

00z Euro has some crazy snow totals.

[Catnip]

Colder camp is growing on this run….

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[Catnip]

EPS looks decent as well.

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[Rubus_Leucodermis]

Yeah, a cold pattern is more stable, but for the big snows you want to be in a high risk/high reward type setup.

Mentioned this yesterday as well but that sharp temp contrast in the west being a reoccurring theme (beginning this week) for what looks like at least another two weeks will lead to significant snows for whichever regions are riding that boundary. That map of the 00z GEM you posted an hour ago is a good illustration of this.

This weekend that line will set up between Prince Rupert/Bella Coola on the coast, east to Terrace/Kitimat, further inland to Williams Lake/100 Mile House and southeast to Revelstoke/Fernie. Forecasts for these regions look very snowy!

Shift that boundary south by a few hundred kilometres and that could be the South Coast during Christmas week... recent examples of this pattern for us locally would be January 2012, February 2017, January 2020, or December 2022. As of now, that's all shifted to the north hence the mild rains around here.

December 1996 was of course the king of that pattern. Pineapple Express duking it out with an Arctic Blast.

[AbbyJr]

Updated 24hr rainfall totals valid from Wednesday at 12:00AM to Thursday at 12:00AM:

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nam-nest-vancouverski-precip_24hr_mm-5440000.png

ecmwf-deterministic-vancouverski-precip_24hr_mm-5440000.png

nbm-conus-vancouverski-precip_24hr_mm-5440000.png

[AbbyJr]

Yeah, a cold pattern is more stable, but for the big snows you want to be in a high risk/high reward type setup.

Mentioned this yesterday as well but that sharp temp contrast in the west being a reoccurring theme (beginning this week) for what looks like at least another two weeks will lead to significant snows for whichever regions are riding that boundary. That map of the 00z GEM you posted an hour ago is a good illustration of this.

This weekend that line will set up between Prince Rupert/Bella Coola on the coast, east to Terrace/Kitimat, further inland to Williams Lake/100 Mile House and southeast to Revelstoke/Fernie. Forecasts for these regions look very snowy!

Shift that boundary south by a few hundred kilometres and that could be the South Coast during Christmas week... recent examples of this pattern for us locally would be January 2012, February 2017, January 2020, or December 2022. As of now, that's all shifted to the north hence the mild rains around here.

Cold patterns have produced big low elevation snowfalls in the past. January 1954 is an extreme example. A deeply entrenched arctic airmass over the south coast met up with a low that stalled offshore for a week. Abbotsford recorded over 100cm with multiple back to back snowstorms.