A humid northeasterly airflow continues to lie over New Zealand on Monday, this will result in more showers and potential thunderstorms in the afternoon for certain regions. There are some slight changes afoot however especially later in the day as the flow may tend more northerly or perhaps even northwest, this is in preparation for a southwest change mid week then an anticyclone later next week where sunny conditions should return less the humidity.

For the upper North Island expect a period of morning rain on Monday then easing to showers as northeasterly winds tend northwest, could be an isolated downpour or two from afternoon, perhaps even some thunder.

For the lower North Island conditions are mainly dry in the morning, a few showers start to move in during the afternoon but still expect dry areas to remain also. Showers could be heavy with thunderstorms about the Manawatu and Wairarapa in the afternoon then easing in the evening. Winds from the northeast then tending north to northwest later in the evening.

For the upper South Island, we see any early showers about the Nelson / Marlborough region clear then some sun breaks through, fairly dry otherwise. Showers develop in the afternoon about inland areas ease of the Main Divide, these showers may become heavy with thunderstorms then easing and clearing in the evening.

Any morning showers clear about the lower South Island then some sun breaks through, showers start moving in to South Westland from afternoon and showers develop about inland areas east of the Main Divide north of about Otago Peninsula. These afternoon showers in the east may become heavy with thunderstorms then easing and clearing in the evening. 

Temperatures are nice and warm for most on Monday, the warmest spot will be about Central Otago and Southland with high’s getting into the mid to late twenties, perhaps even early thirties about sheltered inland valleys. Keep an eye out for any thunderstorms that develop tomorrow, with the humid air mass we have at the moment any storm that does develop could produce very heavy downpours and bring a chance of flash flooding.

Image: Monday 3rd December 2018 4:00pm MSLP / Rain map – weathermap.co.nz

By Weather Analyst Aaron Wilkinson – WeatherWatch.co.nz