Though most storms that form in the Southwest Pacific have little to no affect on New Zealand, it looks like this may not be the case over the next week for the islands.
Tropical Cyclone 18 formed just to the east of Vanuatu early Monday morning, local time. Though tropical systems form often around this region, most either track off to the west or push into the open waters of the Coral Sea or the Pacific Ocean.
This storm is looking different from those as it looks to push off to the south over the week and approach New Zealand and the northern island for the end of the week and into the weekend.
Though the exact track can vary some, it looks to slowly push off to the southeast and away from Vanuatu early this week before it picks up forward speed and moves south towards New Zealand.
The strength of Tropical Cyclone 18 is expected to increase over the week as it starts its trek towards New Zealand. It looks to gain strength and could eventually be as strong as a Category 1 hurricane in the Atlantic or eastern Pacific. If this is the case, waves will increase with this along with some higher waves as this moves towards the coastline.
No matter the strength of the storm, New Zealand at least looks to get some beneficial rainfall. Rainfall for Auckland, which is in northern parts of the island, has seen just 8 inches (20 cm) since October, well below-normal rainfall of 18 inches (45 cm).
Though there will be welcome rainfall, flooding may also be a problem from the rain over much of the northern island. Rainfall could be over 5 inches with this storm as it moves over the island. That could cause some landslides and flooding in some of the more mountainous terrain of central New Zealand.
Coastal flooding could also be a major problem with higher waves likely as the storm rapidly approaches from the north. If this system does become a stronger tropical cyclone, it could bring waves over 6 feet (2 meters) to the coastline.
Winds look to be strong as it moves through, despite the storm trying to weaken as it moves southward. Water temperatures are much cooler over New Zealand, however, this storm looks to transition into a non-tropical cyclone as it moves towards New Zealand. Despite whatever it is named, wind gusts over northern areas and into the mountains could easily gust to over 75 mph (120 kph) as the storm accelerates off to the south.
Story by AccuWeather.com Meteorologist Alan Reppert