KEY POINTS:
Spring makes a sudden return this week as a large low moves across the Tasman Sea bringing with it wind, rain, showers and thunderstorms.
The deep low passed over Melbourne during the weekend and will bring a mix of weather extremes across New Zealand over the next 48
hours. Actually Melbourne is a good area to keep an eye on. Quite often when Melbourne has a nasty southerly change it reaches New Zealand a couple of days later.
The low looks likely to cross the South Island during Tuesday so I expect the heaviest rain to be over the West Coast - that's not exactly a tough one to work out though! The North Island will also see some decent rain along the west coast and possibly in north facing areas such as Bay of Plenty, where those rain clouds get driven in by the northerly flow and then build up against the ranges that surround the Bay.
For Auckland and Wellington it's going to be a windy, cloudy and then wet start to the week - and really the south'west change might mean a windy week all week.
In my blog on Friday we talked about the 'disturbed' weather patterns. This is exactly what a disturbed pattern looks like. This week is back to spring-like weather with strong winds driving temperatures up to 30 degrees in the east, while heavy rain and thunderstorms pound the west. The whole system is followed by a cool southerly change that will see temperatures in the South Island falling from the 20s back into the teens.
Our government forecaster is predicting a pretty good chance of thunderstorms in western parts of the country. If you want to track the thunderstorms when they arrive check out our free and live Lightning Detector here. The actual lightning detectors are privately owned by a few weather enthusiasts across New Zealand and I appreciate the fact that they've allowed us to link them all together at the Weather Watch Centre.
It's an awesome page to watch when the weather gets really severe - during major thunderstorm events you can get well over a thousand strikes an hour - although I doubt this system will produce anything like that!
As I said temperatures in the east will soar, places like Gisborne and inland Hawkes Bay will be pushing 30 degrees on Tuesday. For farmers this is more bad news with only small amounts of rain likely to make it across the ranges that hot wind will suck any moisture back out of the ground again.
In Canterbury it may be a little better with more rain and temperatures a little lower. In fact Canterbury may see more rain or showers this weekend. Some computer models are showing another low creating south easterlies by Saturday and driving in some shower activity. It's one to watch and of course I'll update you about this on Friday.
Finally, we had a tonne of reports yesterday about the Meteor seen over Auckland and northern New Zealand. Did you see it? Read some eye witness accounts of it here.
As always, we love getting your feedback on either my blogs or simply commenting on weather conditions where you are - and maybe your own predictions of Christmas Day. Use the comments section below to share your thoughts. Have a great week!
Philip Duncan
Pictured above: Dark threatening clouds viewed by farmer Ron Higgins on his Brightwater farm near Nelson. Photo / Brett Phibbs
For the latest weather news keep up to date with The Radio Network's new Weather Watch Centre or the NZ Herald weather section.