Weather ‘Waffle’ or the real deal?


We’re hearing a little about ‘significant winter stratospheric warming’ and associated cold and wet weather. But does it carry any substance? Any practical implications – in short, no, not at this stage.


•We touched on possible changes in our weather patterns for Spring earlier last week. Earlier computer guidance suggested wintry weather this week; we’re now looking at a rather dry week bar a couple of brief southwest changes and associated showers on Friday & Saturday. Highlighting how even 1-10 days can provide constant curve balls.

•Currently this are no systems of interest; in terms of significant rain or snow in the next 10 days.

•We’ve seen a fairly ‘active’ August matching our monthly outlook; there are links between Southern Annular Mode (SAM) and our more active period of weather. But in reality, this hasn’t been significant and is extremely unlikely to be over the next 10 days. Normal late winter patterns are present.

•Speculation there is significant weather 10-15 dates out needs careful moderation. There is some model indication that between the 2nd of September to the 7th we may see some surges of bitterly cold air; this may actually prove to be more south-westerly fronts and more rain for the Main Divide and possibly some lower level snow for Otago and Southland. Models and data often over play longer range numbers; this may change and remains a ‘fluid’ situation. Something we’ll continue to watch closely; especially as we move into early stages of next week.

•There are  indicators that September will be a colder and wetter month over all. It is likely that we’ll see an increase in south-westerlies and westerly rain events and brief periods of colder weather from more direct southerlies; as is often the case in September; but perhaps a higher frequency.

•We touched on a wetter and perhaps stormy September in our July and August monthly outlook; this remains the case with low pressure anomaly rather distinct even into October; possibly indicating a colder and wet end to Spring 2019. Long range computer guidance usually carries some substance; but once again we can’t pin point exact fronts and systems past 10 day. There is a chance low pressure anomaly could be slightly swayed by higher than average rainfall across the Main Divide. 

•Bottom line? There are indications of a wetter & colder spring, possibly suggesting we may see a higher frequency of colder southerlies and snow about the hill country. At this stage in terms of practical implications; it’s a wait and see approach in many respects as is often the case.

•Keep up to date with our ‘Live Weather Feed and town pages for all the latest information. Out Monthly outlook which provides the most detailed and comprehensive longer-range analysis for Canterbury will be issued on the 2nd of September providing more of an insight into the month ahead.

(C) NZ Regional Weather Updates.