He told the Ghana News Agency in an interview, that the sea had become warmer, causing evaporation, which resulted in cloud formation.
Mr Portuphy said this warming of the sea, was the result of pertaining atmospheric heat, caused by the current movement of the sun across the equator towards the northern hemisphere.
He said as a result, although the country was still in the harmattan season, weather systems that caused rainfall, were developing over the sea.
Mr. Portuphy said although this morning’s rain was reported to have caused flooding in certain parts of Accra, it was just a moderate down pour and could not be considered as a heavy one.
He said more of such rains could be expected before the rainy season, because of the pertaining weather.
“This serves as a curtain raiser, so we must prepare for the actual rains,” Mr. Portuphy said, adding that, there was the need to clear drains and gutters for easy passage of water.
“Let us be particularly cautious with flood-prone areas,” said the senior meteorologist.
Mr Portuphy said this morning’s rain-fall first developed on the sea and moved in-land towards Winneba, Cape Coast and Takoradi.
He said the rainfall records ranged from 0.8 millimeters (mm) around the Airport, to 24.7mm at Saltpond.
The down-pour this morning, is reported to have caused flooding in certain parts of the country’s coastal and surrounding areas.
Residents in some areas that were affected, such as Mallam and Kasoa, say there was heavy vehicular traffic as a result of the floods.