MIAMI -- Tropical Storm Arthur, the first named storm of the 1990 Atlantic-Caribbean hurricane season, formed Tuesday and moved over the Lesser Antilles, dumping heavy rain and causing flooding over Tobago.
At 10:30 p.m. EDT Tuesday, Arthur was centered near latitude 11.2 north, longitude 60.5 west, over Tobago.
Tropical force winds extended as far as 70 miles from Arthur's center.
Maximum sustained winds were near 45 mph, above the threshold of 39 mph for tropical storms. Arthur was moving west near 20 mph and was expected to continue that motion through Wednesday then turn more toward the west-northwest into the Caribbean, said forecaster Lexion Avila at the National Hurricane Center in Miami.
He said little change in strength was expected over the next 24 hours.
'The main concern is the rain,' said Avila, who described the storm's strength as 'minimal'
Tropical storm warnings were posted for Trinidad, Tobago, Grenada and its dependencies, as well as Barbados.
The storm was expected to dump as much as 5 inches of rain and produce local flash flooding Tuesday night in Trinidad, Tobago, coastal Venezuela, Grenada and the Granadines.
Avila said the hurricane center was taking a wait-and-see attitude on the storm's progress.
'Let's see what happens when it gets south of the Domincan Republic in the next three days,' he said. 'But still we don't see any reason to believe it's going to be a hurricane within the next three days.'
Arthur formed from the season's second tropical depression.
The year's first tropical depression brought heavy rains to Cuba in late May, before the official start of the hurricane season, which runs from June 1 to Nov. 30.