A trough of low pressure just to the North of Fiji is gradually moving over the group and associated cloud and rain is expected to affect the country until Friday morning.

The Fiji Meteorological Services says another trough of low pressure extending from the West to the South of Fiji is anticipated to intensify and move towards the group and affect the country this weekend.

The public is advised to expect occasional rain which will be heavy at times and thunderstorms expected over Vanua Levu, Taveuni and nearby smaller islands, Yasawa and Mamanuca Group, Northern Viti Levu, Lau and Lomaiviti groups.

There will be cloudy periods with some showers expected over eastern Viti Levu.

Showers are anticipated to increase to rain which will become frequent and heavy at times with a few thunderstorms from tomorrow.

Moderate east to southeast winds, fresh at times is anticipated.

Winds may increase further and become fresh to strong from Friday as the trough of low pressure from the west draws closer.

The weather office says for the rest of the country, fine weather is expected apart from isolated afternoon or evening showers that will increase to rain, becoming frequent and heavy at times with a few thunderstorms from tomorrow.

Moderate east to southeast winds, fresh at times is also anticipated.

Winds may increase further and become fresh to strong from Friday.

Rain is expected to ease from mid-morning and bring some breaks with sunshine.

However, rain will return and become frequent and heavy at times from Saturday.

The system has the potential to produce more than 50mm of rainfall in 24 hours and may cause flash flooding in areas where there is the occurrence of persistent localized heavy rainfall.

Therefore, all communities living in low lying and flood prone areas are advised to stay alert and take precautions when necessary.

Mariners can expect moderate east to southeast winds, fresh at times with moderate to rough seas. Winds likely to increase and become strong and gusty from Friday.