July suddenly unsettles
A low out over the Tasman will be our weather-maker for the next several days.
The low will start to rotate a trough of low pressure across the country tomorrow. As early as tomorrow afternoon, the northern tip of the North Island could start to see some light showers. By tomorrow evening, those shower chances will move south into Auckland.
By the time Tuesday morning rolls around, almost all of the North Island will be getting wet.
At this time, heavy rain is a possibility. Government forecaster MetService says Northland, Northern Auckland, Coromandel Peninsula, western Bay of Plenty and Rotorua all run the risk of seeing rainfall heavy enough to warrant warnings. A low risk for heavy rain extends to the rest of Auckland, northeast Waikato and eastern Bay of Plenty. WeatherWatch.co.nz forecasters agree with MetService, but also feel that Taranaki should be on the lookout for heavy rainfall Tuesday evening.
The low and its associated trough (also sometimes called a boundary) will continue to drift south on Wednesday. That means rain chances will spread onto parts of the South Island. The West Coast and Nelson could see some rain. But other than a few light showers early on Wednesday, the eastern side of the island will probably see very little, if any rain.
Thursday could bring some small rain chances to most of the North Island. The South Island may see some light rain along the West Coast. Light rain is possible on the other side of the island as well. During the night, the rain may change to snow in the higher elevations.
Light rain or snow will continue to be possible for eastern Otago on Friday. Snow levels will likely stay above 400m. Some light rain is also possible for Marlborough. Otherwise, the South Island should be fairly settled. Much of the North island will still be feeling the effects of the slow-moving Tasman low as it starts to push ashore. The whole island will see a chance for showers with the best chance being about Auckland, the Coromandel Peninsula and the Bay of Plenty.
By WeatherWatch Analyst Howard Joseph