For the last few days, it’s been pretty obvious that there was going to be at least some heavy rain showing up today.  The western regions of the South Island seemed to be the most likely candidates for getting heavy rain.  Eastern Bay of Plenty and Northern Gisborne seemed likely to see heavy rain as well.

Now that the incoming low is really starting to show its hand, it’s becoming much clearer where the heaviest rain will fall.  Potential rainfall amounts are also become clearer and it looks like they are going to reach warning criteria in some areas.

So, Government forecaster MetService has gone ahead and issued the following warnings for heavy rain:

• Westland and Buller-  Heavy rain is likely through Wednesday morning.  During that period, 150 to 200mm of rain is expected for the ranges, 70 to 100m is expected for the coastal areas.  Peak intensities likely to occur tomorrow afternoon with 10 to 15mm/hr possible.

• Eastern ranges of Bay of Plenty-  Brief heavy rain is possible through this afternoon.  Widespread heavy rain is expected starting tonight and lasting into tomorrow morning.  70 to 90mm of rain is expected with peak intensities of 15 to 20mm/hr during the morning tomorrow.  Intense rainfall is possible this evening and tonight as well, but would most likely to be associated with thunderstorms that may develop.

Heavy rain is also possible about the lower and western North Island.  However, it’s more likely that wind will be a problem.  Severe gales are possible about southern Taranaki, inland Wanganui and Taihape this afternoon.  Any heavy rain is likely to be associated with thunderstorm activity that may develop.

The main risk for thunderstorms will be from Northland and Auckland through to Taranaki this afternoon.  There is also a chance for thunderstorms for the Kapiti Coast this afternoon, but the risk is very low.

Road snow warnings for Porters Pass, Lindis Pass and Arthurs Pass are expected to be lifted early this afternoon as snow turns to rain.

By WeatherWatch.co.nz Weather Analyst Howard Joseph