Surf on O'ahu is down a bit today, but a new northwest swell could arrive as early as tomorrow, the National Weather Service said.

For today, look for surf of 4 to 7 feet along north-facing shores; 2 to 4 feet along west- and east-facing shores and 1 to 3 feet along south-facing shores.

Outlook through Saturday, Jan. 31: The current northwest swell will gradually diminish into Monday.

The expected development of a low pressure area north of Kaua'i today will result in a northwest swell that may warrant a high surf advisory for the north- and west-facing shores as early as Tuesday.

This swell will be followed by a small to moderate longer period northwest swell Friday night and Saturday.