Winter 2020-2021

[Michael1]

Phil on the American forums told me that he doesn't think there is any evidence to suggest the Nina intensity has anything to do with cold and snow in the PNW. Rather, its external factors apart from ENSO. He gave examples of some of the better PNW winters that were El Nino but said that it doesn't prove that El Nino favours colder and snowier winters here. Its just that external factors can overcome a less favourable ENSO.

That said, even if Nina intensity was a factor, this upcoming Nina will likely end up moderate at most. So we should still be good to go to get our December 1996 and January 1954 redux we have all been patiently awaiting.

I would point out that there is a difference between temp and precip. While it may be true that snowfall might be less, that is because a La Nina favours more intrusions of dry arctic air and a less persistent moist southwest flow, generally speaking. WE might get record low temps, with only moderate snowfall. Winter 1988/89 was a strong La Nina and although Victoria received some snow, the bigger story was the run of days that the local lakes and ponds were frozen enough to walk on. I'm holding out for snow, but cold is nice too.

[Typeing3]

Yes, it could be merely coincidental that strong La Ninas have historically been associated with lower snowfall.

An argument could definitely be made that strong La Nina's feature less blocking than weak/moderate ninas though.

Strong Nina's historically tend to feature a strong zonal or NW flow where we see well above average precip and occasionally score big snows with brief overrunning events or systems dropping down the coast.

[Typeing3]

These climate plots can go back to 1895. Unfortunately there's been too many weak Nina's since then to fit in the plot but I've put in as many as possible stretching back to 1915-16.

Weak La Nina temp anomalies:

cd162.156.4.68.268.23.51.18.prcp.png

Weak La Nina precip anomalies:

cd162.156.4.68.268.23.52.37.prcp.png

[Typeing3]

Moderate La Nina temp anomalies:

cd162.156.4.68.268.23.58.52.prcp.png

Moderate La Nina precip anomalies:

cd162.156.4.68.268.23.59.20.prcp.png

[Typeing3]

Strong La Nina temp anomalies:

cd162.156.4.68.269.0.2.0.prcp.png

Strong La Nina precip anomalies:

cd162.156.4.68.269.0.2.34.prcp.png

[Typeing3]

Overall, looks like temp anomalies for our area during weak and moderate La Nina's is about -1.5C. A tad warmer during strong La Nina's at -1.0C.

Precip anomalies gradually increase with Nina intensity...from +2-10cm during weak events to +3-15cm during moderate events and finally from +5-17cm during strong events.

[AbbyJr]

An argument could definitely be made that strong La Nina's feature less blocking than weak/moderate ninas though.

Strong Nina's historically tend to feature a strong zonal or NW flow where we see well above average precip and occasionally score big snows with brief overrunning events or systems dropping down the coast.

Very true. Good point.

That said, I think an argument could definitely be made on both sides of the debate.

[Michael1]

Very true. Good point.

That said, I think an argument could definitely be made on both sides of the debate.

In the end, all of us are still left waiting to see what will actually happen

[Monty]

These climate plots can go back to 1895. Unfortunately there's been too many weak Nina's since then to fit in the plot but I've put in as many as possible stretching back to 1915-16.

1915-16 now that was a winter.

[Michael1]

1915-16 now that was a winter.

Victoria, February 1916, Government Street:

blizzard_of_1916001.jpg

[Typeing3]

1915-16 now that was a winter.

212.9cm that winter at the old New West station. Mostly falling between late December and early February. January had an average high of -1.4c and a mean temp of -4.3c.

[AbbyJr]

212.9cm that winter at the old New West station. Mostly falling between late December and early February. January had an average high of -1.4c and a mean temp of -4.3c.

Insane.

[Michael1]

The latest SST forecast for the ENSO regions:

20200929.sstOutlooks_nino34.png

[Typeing3]

The latest SST forecast for the ENSO regions:
20200929.sstOutlooks_nino34.png

At face value I believe that would be the strongest Nina since 1988-89.

[AbbyJr]

At face value I believe that would be the strongest Nina since 1988-89.

And 1988/89 was a -QBO. This upcoming winter should be a +QBO. Maybe we can actually get an epic winter?