Yesterday's cloudy, humid weather dumped nearly 2 inches of rain in some spots but only traces in others.

Over a three-hour period, some rain gauges registered up to nearly 2 inches from the cold-front weather pattern that has cloaked parts of the state.

By contrast, the rain gauge at the Pālolo Fire Station registered a scant .10 inch of rain in the same period.

But despite the uneven rainfall pattern around the island, the National Weather Service issued a flash flood watch for much of the weekend for O'ahu, Ni'ihau and Kaua'i through midnight yesterday.

Today, and through the rest of the week, officials say there will be a gradual clearing and by late week the trade winds will reappear. The vog, however, will remain over other Islands until the trade winds clear the air tomorrow, the weather service said.

"I understand there's not been any serious flooding to this point," meteorologist Vladimir Ryshko said last night. "We're not expecting widespread flooding at this point."

The weekend weather, Ryshko said, comes late in the year "for this type of weather pattern."

The front came from the west to combine with an upper-level trough to make the atmosphere unstable near Kaua'i and O'ahu, the weather service said.

The conditions, combined with "abundant" low-level moisture, will increase the likelihood of heavy rainfall and flash flooding over the western end of the Hawaiian chain.

A flash flood watch means that flash flooding is possible but not imminent in the watch area. Residents are advised to monitor weather forecasts and be prepared to act should a flash flood warning be issued.

On O'ahu, the Pālehua gauge on the southern end of the Wai'anae mountains recorded 1.59 inches of rain throughout the day while the Schofield South gauge registered 1.68 inches.

"Earlier it rained a lot out here," said Cecilia Cambia, a hostess at the Mililani Golf Club restaurant. "I thought the haze was vog, but I think it's just the clouds."