Boaters can expect diminishing and shifting winds across Long Island waters for most of Wednesday, the National Weather Service said.

A west-northwest flow early Wednesday will give way to a southerly flow in the afternoon, the service's Upton office said.

A backdoor cold front approaches late in the day, and another wind shift to the east will develop "late in the day and through the evening hours," the service said.

The flow east continues for the remainder of the night and through the day Thursday; some small-craft-advisory conditions are expected through the day Thursday.

Wind speeds for most waters will be 10 to 15 knots at the high end, with a drop to 5 to 10 knots later in the day.

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Moriches Inlet to Montauk Point could see some early morning gusts of as much 20 knots.

Winds for Friday and the weekend pick up significantly, the service said.

Wednesday's weather forecast for most of Nassau and Suffolk counties calls for mostly sunny skies and temperatures near 70, the service said.