North and south hemisphere weather

[rowan]

I have been noticing over the last few years that up in the Northern Hemisphere you tend to follow our weather patterns and I have started this thread to see if this is actually the case or I have been imagining it. I thought I will describe the seasons here and if it corresponds with yours six months later someone would remember to say so. Keeping in mind that I have a mediterranean climate.

Starting off. The Autumn here has been very late. The deciduous trees have changed colour a month later than usual. I have never seen them this late. The nights are cool but the days are still unusually warm for this time. Still no sign of autumn rain apart from the occasional light shower. 

[reed]

I'm pretty close to the middle of North America along the Ohio River, maybe a little east of the middle, 38°N, 85°W. Our fall has become largely non-existent, basically unrecognizable as a distinct season. Most years it just stays hot and dry till one day when it freezes. Fall rains are rare now.

We don't have fall color in the deciduous trees anymore, many are already dead and not just form the Emerald Ash Borers. Thousands of acres of hillsides that used to blaze with with red, orange and yellow for a month or so are now mostly just patches of various shades of brown.

I'v read that the southern hemisphere is behind on the changes because of land vs water configuration and that the ice on the southern pole sits mostly on land where ours all floats. Making it subject to melting faster as the ocean warms. If you still have fall color even if later it fits with that.

[richardw]

As you say reed the land vs water configuration here in the south is really just a massive blob of ice surrounded by water, the Southern Ocean provides a degree of thermal stability that keeps the jet streams more stubble than in the NH. The northern hemisphere is the opposite, the polar region is surrounded by land and this resent NH winter has shown how these jet streams are been increasingly disrupted by a warming arctic ocean, an ocean that is barely able to have develop a winter ice sheet anymore.
I think no, there is no connection between the seasons north and south.

[keen101 (Biolumo / Andrew B.)]

Yes to some degree. Though AU apecifically. Haven't for some time though i must admit. But yes, particularly extreme weather. Is it true that recently in 2009 or so you experienced heavy erosion and a a giant dust storm similar to our dust bowl during our great depression?

And around that time i had seen an article that said you had experienced your first recorded tornado because if climate change. But i now wonder how true that is. I'm sure you get plenty of cyclones or tornados but not being a local i don't know for sure.

[rowan]

I know you are all sceptical but I am going to continue this thread just to see where it goes for the year. If I am wrong them no harm.

Autumn is continuing to be unusually hot with record breaking temps for this time of year. A few showers but no real autumn break yet.

[philagardener]

Any differences between northern and southern hemisphere weather are based on circumferential evidence! 

[richardw]

What i found it interesting when comparing northern and southern hemisphere weather in just how dissimilar the two are. The southern hemisphere has its 'roaring 40"s', a westerly air stream that has its greatest affect on NZ, Tasmania and southern South America, less so for mainland Australia and southern Africa. Driven mainly by the vast amount of ocean it helps maintain a relatively stable both polar and subtropical jet stream system. The resent northern hemisphere winter has shown how less stable these jet streams have and are becoming, predicted years ago that this may start to happen too, bit of a worry for the future ?.

[rowan]

www.sciencealert.com/new-zealand-index-jet-stream-sea-surface-temperature-rainfall-prediction-california

This same weather pattern that occurs in NZ also is the same as southern Victoria where I am.

And for the record our winter started with more frosts and rain than usual. generally we don't get this rain until mid July.

[richardw]

In yet the opposite here, this mornings frost was the first major one of the winter.

[RpR]

Hard to say, in the past twenty years, give or take, we have had being able to plant corn in by the first week of May, with summer temps, day time 70 F, through October, while at the same time, within ten years of each other,I have not been able to put a full garden in till June with -13 F sub-zero and feet of snow in the last week of Oct.

In the nineties we had both drought conditions, non-irrigated corn fields dead by July and record snow a few years later.
I was able to grow 160 day corn , with ripe cobs, early in the oughts.
I remember sub-tropical weather when I was in grade school, while in the past ten years we have had two such summers.
Sub-tropical summers are not unusual but these two seemed to last longer.
With all the whining and other such moronic comments you hear from weather dweebs during sub-zero in winters you would think we were getting unusually cold winters but for the past eight at least cold snaps are twenty degrees warmer than -40 F we had up here several years thirty years ago and rarely close to truly deadly cold with sets in around -25.

Now I will admit that at one point I thought our averages were continually higher but about the time I was ready to plant zone 5 plants winter showed me I was wrong.