General September Weather

[cbm]

22.3C on mine and still very sunny. More official sites nearby hitting 21C

Edit. Now hit 24.1. Hamilton Airport now 22.6 so not too far fetched. Felt weird at lunchtime having summer like temperature, but with Kowhai in full bloom and some deciduous trees still bare.

[Simon Culling]

NIWA tweet gives a range of 25.6*C at Hanmer Springs for Wednesday 19th September, with the mercury rising from an overnight low of -3.1*C to a max of 22.5*C. That's a decent diurnal range.

https://twitter.com/NiwaWeather/status/ ... 9419999232

[NZ Thunderstorm Soc]

NIWA tweet gives a range of 25.6*C at Hanmer Springs for Wednesday 19th September, with the mercury rising from an overnight low of -3.1*C to a max of 22.5*C. That's a decent diurnal range.

https://twitter.com/NiwaWeather/status/ ... 9419999232

It was a wee bit like that here in Geraldine.
From minus 0.9C, it got up to 20.3C, much warmer than at Levels and other coastal areas, ie. Temuka, although it wasn't that much warmer according to temperatures in this morning's Timaru Herald for Fairlie and Twizel.

[cbm]

Trying to remember how to drive Cliflo again - but today got to at least 22.6C at Hamilton Aero. It may be second highest September temp for either Ruakura or Hamilton Aero sites, beaten only by 30th September 1973's 23.6.

[NZstorm]

It's looking like an unstable robust cold snap next week, especially for the SI.

Latest models showing a decent trough crossing the South Island Monday with a heavy snow risk for inland parts. Also wintry showers on the southern coast.

[Bradley]

Latest run of EC out an hour ago now has the low positioned just off the Canterbury coast for Monday with a considerable fetch of cold air, only one run of course but EC has the snowline right down to 100m with 10-20cm above 300m for Mid-Canterbury...

[Captain Salty]

And yes, the ozone hole usually peaks around mid October...

you mean the ozone layer is at its thickest in October, right?

[Richard]

No, its normally at it's thinnest mid spring

[melja]

I don't know if it's thinner but the hole is normally at its greatest extent and generally around the south pole if I remember correctly?

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[Captain Salty]

This graph is confusing me then, if someone can explain

ozone_lauder.png

[Richard]

Well i was lead to believe that we were at the greatest risk from UV in spring because of thinning

[NZ Thunderstorm Soc]

Well i was lead to believe that we were at the greatest risk from UV in spring because of thinning

Well, Richard. Keep your hat on. wear lots of protective clothing and don't have any ideas of joining a nudist colony this year

[Richard]

No chances of that John unless it was a breeding colony.

[Dean.]

https://www.metservice.com/warnings/sev ... er-outlook

Severe weather outlook has been updated for a heavy snow risk for inland Canterbury

[Chris W]

MetService tweeted earlier that they expected to raise the confidence to moderate for that snow outlook and now they have. Snow to 2-300m for the South Island and 5-600m for the North Island.

[Nev]

And yes, the ozone hole usually peaks around mid October...

you mean the ozone layer is at its thickest in October, right?

No, I mean the Antarctic ozone hole is usually at its thinnest in October. But yes, NZ also normally finds itself under a ridge of high ozone during October. However, ozone levels worldwide are still below what they were earlier last century. Combine that with UV levels naturally rising in spring and peaking around our Dec solstice.

Note that the ozone hole was at its largest around the beginning of this century and its outer reaches would occasionally extend closer to NZ. However, it is very slowly shrinking due to the global reduction in the use chlorofluorocarbons (CFCs) and scientists expect it to more or less make a full recovery in about another 40 odd years.

[NZ Thunderstorm Soc]

Cold southerly came through around 5pm. No rain yet.

[Chris W]

I see the snow outlook now covers inland Otago through to North Canterbury above 400m. There is now an outlook for heavy rain and gales from Chch northwards for Tuesday, so one to keep an eye on.

https://www.metservice.com/warnings/sev ... er-outlook

[03Stormchaser]

Almost the whole country under the thunderstorm outlook today

Capture.JPG

[Cyclone Tracy]

Tropospheric gravity wave clouds now appearing in the uppers to the east of the polar front. Becoming quite unstable aloft

[Dean.]

Overcast and occasional drizzle here...unless it ramps up soon it will be another non event

[snowykiwi]

Same here in Methven, drizzle and overcast and not cold enough for snow in my opinion.

[Cyclone Tracy]

Prefrontal trough showing some signs of a developing squall line moving towards west coast of the NI on the 3.30pm radar

[melja]

Clearing up to blue sky in Rangiora with a whole 0.7mm of rain, not cold either with it hitting 14C.

Well if it is a fizzer there will certainly be egg on the faces of the Facebook forecasters.

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[Razor]

Forecasting in general has been seriously difficult and lately, virtually every front not doing what it should. Lovely run in the Port Hills this arvo but noted reasonable instability around but no action here