WAILUKU - A couple of high-pressure systems - one to the north and one to the northeast - are expected to begin building the strength of trade winds today and continue through the rest of this week, said Glenn James, senior weather analyst with the Pacific Disaster Center.
Trade winds had been light to moderate, but they are forecast to strengthen to strong and gusty this week, James said, adding that small-craft advisories should go up today for coastal and channel waters surrounding Maui County.
The winds should hit their stride Thursday and continue into what's expected to be a breezy weekend, he said.
Casting next to a World War II bunker in Paia, a fisherman tries his luck last week. Maui County residents can expect stronger trade winds this week and a swell of high surf coming from the northwest, according to Glenn James, senior weather analyst with the Pacific Disaster Center.
The Maui News / MATTHEW THAYER photo
The National Weather Service said high temperatures will be 76 to 81 degrees, with overnight lows of 63 to 68.
Also, because of the stronger winds, east-facing shores will be rough and choppy, James said.
The strong winds are not expected to bring much rain, other than the common passing showers, at least through Friday, he said. However, beginning this weekend and into next week, residents, particularly in windward areas, may see increasing showers.
For the 24-hour period ending at 2 p.m. Tuesday, only Puu Kukui, deep in the West Maui Mountains, recorded a significant amount of rainfall - 0.71 inch.
County Department of Water Supply records show that the Wailoa Ditch, which collects water from East Maui surface sources, was running between 72.6 million and 189.6 million gallons per day last week.
The ditch has a capacity of nearly 200 million gallons per day.
Two of Upcountry's main water supplies were full or near full. The 100-million-gallon Kahakapao Reservoir was about 95 percent full, and the 50-million-gallon Piiholo Reservoir was full Tuesday, according to the water department.
James said the high and mid-level clouds that have made for overcast skies recently may move on today.
"The high clouds might be trying to slip away," he said.
Meanwhile, a winter swell is expected to arrive late today, James said.
It was churned up by a deep low-pressure area several days ago in ocean waters off Japan, he said. The area had gale- and hurricane-force winds that generated a "swell train of waves" headed in the direction of the Hawaiian Islands.
The surf on north- and west-facing shores is forecast to begin arriving late today and early Thursday morning and continue through the rest of this week, James said.
Surfers might check out breaks at Hookipa, at Honolua Bay and at Jaws in Peahi, he said.
While the size of the surf will be significant, around 20 feet, it's not expected to be among the largest swells of waves this winter, he said.
With waves dangerously big on the north and west shores and windy and choppy conditions on east shores, visitors looking for calm waters for swimming this weekend should plan to go to the south shores where waves are expected to be "very small to near flat," James said.
James' weather forecast can be found online at hawaiiweathertoday.com.
* Brian Perry can be reached at email@example.com.