A southwest airflow lies over New Zealand today, a rapidly approaching front and low combination move onto the lower South Island this afternoon then pushes northwards in the evening bringing in a cold change. This strong southerly quarter change moves over the North Island on Wednesday, conditions gradually ease further south.

Morning showers along the western side of the North Island then long dry spells develop in the afternoon, showers move back in during the evening. Rain about Wairarapa and a few showers further north then drying out during the afternoon. Showers then heavy rain with a chance of thunderstorms pushing northwards along the West Coast of the South Island during the day. Heavy showers with a risk of hail move into Southland early afternoon reaching North Canterbury in the evening with a strong to gale southwest change, thunderstorms possible for Canterbury with the change. Snow lowers to 300m about Southland / Otago and 400m for Canterbury as the cold change pushes through.

Heavy rain or showers for most North Island regions on Wednesday morning, hail possible also. Conditions easing in the west from afternoon then along the east coast in the evening. Expect strong to gale southwesterly winds for some coastal areas especially Northland and Auckland then easing by evening. Some snow about hills and ranges of the lower North Island down to 500m. A sunny day for the West Coast and Nelson, early heavy showers and snow to 500m about Marlborough clears then afternoon sun breaks through. Heavy rain or showers about Canterbury with a risk of hail then easing, clearing South Canterbury in the morning then further north in the afternoon. Some snow about Canterbury to 300m before clearing. Morning showers and snow flurries to 300m about Southland and Otago clear then sun breaks through, later in the evening or overnight rain moves in with a gusty SW change.

By Weather Analyst Aaron Wilkinson – WeatherWatch.co.nz