It, therefore, urged the public to take the necessary precautions in order to stay safe.
An earlier forecast on Sunday said the rainstorm was expected over parts of the Volta, Eastern and Greater Accra regions.
The GMA has urged the public to take safety measures to minimize casualties during this year’s major rainy season.
Southern Ghana is currently experiencing heavy rains, which started about 1700 hours GMT.
Mr Michael Padi, the Senior Meteorologist, says people should be particularly careful when moving during a downpour as drains overflowed making it difficult to determine which area was safe.
“It is best to find some near-by safe shelter, and wait for the floods to recede before moving,’’ he said.
Mr Padi said the public must avoid seeking shelter under weak structures or underneath shady trees, because the rains would, typically, be accompanied by strong winds, which may put one at risk.
He said structures with pointed roofings attracted lightening and were unsafe for use as shelter.
“From experience, people are aware of the toll of heavy rains on their various vicinities, resulting in flooding, and so they should move to safer places during heavy rains,” he said.
Mr Padi urged drivers to be extra careful when it rained because slippery roads made driving more dangerous and flooded roads made it difficult to tell where a huge gutter or drain was. “The best thing to do when it is raining heavily is to stop and take a shelter in the safest place available,” he said.