A typical spring front that is loaded with moisture will continue to spread rain across the western sections of the South Island today and then across much of the country tomorrow.

Government forecaster MetService has issued warnings for heavy rain for Westland, south of Otira.  Rainfall rates could exceed 15 to 25 mm/hr today through tonight.  Up to 200mm may fall by tomorrow morning.

Warnings for heavy rain are also up for the headwaters of the Canterbury lakes and rivers south of the Rakaia River.  100mm of rain is possible near the divide.  About 50mm is possible 10km east of the divide.

Other warnings include;

• The Ranges of Buller, including the Paparoa Range-  Another 100 to 150mm or rain is expected by tomorrow morning with peak rates of 15 to 20mm/hr tonight and early tomorrow morning.
• Ranges of Nelson west of Motueka-  Another 130 to 180mm of rain is expected by mid-morning tomorrow.  Peak rates of 15 to 20 mm/hr are likely tonight and early tomorrow morning.
• Richmond and Bryant ranges-  Heavy rain is expected to develop this afternoon and last through tomorrow morning.  100 to 120mm or rain is expected with peak rates of 15 to 20 mm/hr tonight and early tomorrow morning.

Overnight tonight, the heavy rain threat begins to shift north as the front gets closer.

Early tomorrow morning, Northland will run the risk for heavy rain.  By late morning Taranaki, Waikato, Bay of Plenty, East Cape/Gisborne and Auckland could also see heavy rain.

In addition, North Islanders will continue to see gusty winds tomorrow.  Expect northerlies ahead of the front and breezy westerlies behind it.

Homepage image/ Peter Shone

By WeatherWatch.co.nz Analyst Howard Joseph