December 2019 Forecasts and Discussions

[Catnip]

Cold run = outlier!

Yup. They usually are.

[PortKells]

See my post about the ECMWF earlier!

Missed that one! But cmon you have to admit you mostly post when the models are on the disappointing side. Not that I have a problem with it, it's pretty hilarious tbh. But I think you are a huge undercover supporter of #teamsnow

[Monty]

Yup. They usually are.

It’s actually a warm outlier a few days after Christmas. Lots of cold members around then

[Monty]

Technical question:

We often use the 500 mb anomaly as means of determining the large scale weather patterns. But what is it exactly that makes the 500 mb anomaly preferred for doing so? Is the fact that the large scale weather patterns (ridges/troughs) occur at the 500 mb level? But even at that, why would we use the anomaly versus the regular 500 mb chart?

You can use the regular 500mb geopotential height map if you wanted to. The 500mb level is mostly used because it has a better representation of the steering patterns that are driving our weather. We do look at surface charts for things like surface pressure when forecasting wind and storms. I think we use the anomaly maps at 500mb because it easier to visualize what is happening in the upper levels. After all, a high or a low is basically represented by an anomaly, if that makes sense

[Typeing3]

It’s actually a warm outlier a few days after Christmas. Lots of cold members around then

Yeah, another improvement over the previous run.

[SouthSardiswx]

Yeah, another improvement over the previous run.

Where l can't see the improvement T3.

[Typeing3]

Where l can't see the improvement T3.

Mean is about 2 degrees cooler than the 18z after Christmas.

[SouthSardiswx]

Mean is about 2 degrees cooler than the 18z after Christmas.

Kool thanks.

[Catnip]

It’s actually a warm outlier a few days after Christmas. Lots of cold members around then

True, I was concentrating on Xmas though.

Fingers crossed things work out.

[Catnip]

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[Catnip]

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[Monty]

True, I was concentrating on Xmas though.

Fingers crossed things work out.

The ensemble is a bit of a mess after the 23rd but the 500mb anomaly on the GEFS looks good. Makes me think we are going to see a pattern change with amplification. We’ll have to wait to see if the details work out in our favour

[SouthSardiswx]

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Lovely!

[SouthSardiswx]

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Outstanding!

[Typeing3]

The ensemble is a bit of a mess after the 23rd but the 500mb anomaly on the GEFS looks good. Makes me think we are going to see a pattern change with amplification. We’ll have to wait to see if the details work out in our favour

Hopefully they do. Looks to be an obscene amount of cold air building over Nunavut towards the end of the month. With a ridge in the right place we could see the lobe funneled towards the PNW. But of course...things rarely work out that way.