Rain is expected to become heavy at times in the Eastern Bay this week as a strong northwest flow covers the country from Tuesday to Friday, with a series of embedded fronts.

Showers are also expected for Tauranga sometime today and tomorrow before becoming heavy a time on Saturday.

The sun is shining in the Bay today but rain clouds are expected to move across the country sometime this week.

The MetService says heavy rain is also expected about the South Island.

'The northwest flow over the South Island and lower North Island is expected to rise to gale at times as fronts pass through,” says meteorologist Peter Little.

Peter says after last week's cold temperatures, warmer weather is expected to dominate the forecast this week.

Daytime temperatures are predicted to push into the high teens and could even surpass 20 degrees in Napier and Hastings.

Peter says last week was the coldest of the year for many parts of the country, with some places dropping to eight degrees during the day.