Mean Sea Level Pressure? (storms, Canada, most, annual)

[Glacierx]

What does a higher value mean? Is it based upon the amount of high pressure systems over your area? Here in Canada the annual mean sea level pressure varies from a high of around 101.8 kPa in the southern interior of BC (around Creston and Cranbrook) to 100.9 kPa in Nain, Newfoundland. Does this mean that the southeastern corner of BC has the best weather in Canada while northern Newfoundland and eastern Nunavut has the most low pressure storms? This seems to make sense since the south coast of BC has the highest sea level pressure during the summer months, the southern interior has the highest pressure during the fall and early winter, the prairies have the highest pressure during the late winter, and the far north has the highest pressure during the spring.

Also, why is the mean sea level pressure lower in northern Canada than southern Canada? Is this a calculation error?

[Joe90]

Here's a map showing the NZ situation. Lower pressure the further south one goes, and much lower in the Southern Ocean, due to the earth's spin I suspect. Mean atmospheric pressure, 1971

[jehane]

If you look at the NZ example provided by Joe90, you can see the mean position of the subtropical ridge. This is a reflection of the Global Circulation cells (Hadley, Ferrell and Polar). Variations across the same latitude show where highs and lows typically sit, strengthen or weaken. I'm not familiar with Canada and you haven't provided a map so I can't comment specifically there.

[kronan123]

here's a global mean pressure map for january and july



a bit OT, but it really explains a lot of the climatic differences imo.