Trade winds will steadily strengthen today and a wind advisory remains in effect for areas of Maui County and Big Island through tonight. Passing showers will continue to move in on breezy to windy trade winds through next week. As usual, these showers will be most frequent during the nights and early morning hours across windward and mauka areas.
This morning's radar and satellite imagery shows scattered showers riding in with the breezy to windy trade winds mainly over windward and mauka areas. Rainfall totals over the past 24 hours have varied quite a bit of rainfall amounts of up to 1 to 2 inches at the wettest areas. 12Z soundings from Lihue and Hilo continues to show an elevated inversion, which explains the higher rainfall amounts. As we go through the day today and into tonight, drier air aloft should really fill in tonight, which should cause the trade wind inversion to strengthen and lower. This will result in the winds becoming more gusty later this afternoon into tonight. Wind gusts in the 50 mph range has been measured at the windier areas of Maui County and the Big Island, where we have a Wind Advisory in effect through tonight. The Wind Advisory may have to be extended through Friday. While we don't have a Wind Advisory for Oahu, we could see wind gusts near advisory thresholds later this afternoon into tonight for select valleys downwind of terrain such as Manoa Valley.
While the drier air aloft should help lower rainfall amounts later tonight, strong orographic lifting from the windy trade winds will continue to produce scattered showers over windward and mauka areas.
For the weekend, windy conditions will likely continue through Saturday. Trade winds could drop a notch on Sunday, but nonetheless breezy to strong trades will likely continue through early next week. Passing showers will continue to ride in with the strong trades especially during the night and early morning hours. Shower coverage could slightly increase towards the first half of next week as we see a subtle increase of low level moisture.
High pressure north of the area will allow fresh to windy trade winds to prevail today and tomorrow. Stability will increase through the day as drier air fills in later this morning, leading to lighter intensity and less frequent showers. However brief showers could still impact windward and mountain areas, especially during the evening and early morning hours.
AIRMET Sierra is in effect for mountain obscuration across windward portions of the Big Island, Kauai, Molokai, and Maui. This AIRMET will likely be canceled later this morning as conditions are expected to improve. AIRMET Tango is in place for low level turbulence over and downwind of terrain. With winds building and stability increasing, this AIRMET will remain in place for at least the next couple of days.
The strong high pressure ridge north of the Hawaiian Islands will maintain easterly trade winds in the strong to gale range through Friday morning. A Gale Warning remains in effect for the Alenuihaha and Pailolo Channels, and Maalaea Bay and a Small Craft Advisory (SCA) for all remaining island waters. Expect SCA to continue into the first half of next week.
Small, short to medium period north-northwest (330 degree) swell energy will decline today. The next small north-northwest (330 degree) swell will move into the Hawaii region on Saturday, increasing surf heights along north and west-facing shores through the weekend.
A series of small, long-period south swells will support near- average surf along south-facing shores over the next several days. Meanwhile, strengthening trades will maintain elevated surf along east-facing shores into next week. Surf heights could approach advisory levels later today along east facing shores.
Wind Advisory until 6 AM HST Friday for Big Island North-Big Island South-Big Island Southeast-Kahoolawe-Kohala-Lanai Leeward- Lanai Mauka-Lanai South-Lanai Windward-Maui Central Valley North- Maui Central Valley South-Maui Leeward West-Maui Windward West- Molokai Leeward South-Molokai North-Molokai Southeast-Molokai West-Molokai Windward-South Haleakala.
Small Craft Advisory until 6 AM HST Friday for Big Island Leeward Waters-Big Island Southeast Waters-Big Island Windward Waters-Kaiwi Channel-Kauai Channel-Kauai Leeward Waters-Kauai Northwest Waters-Kauai Windward Waters-Maui County Leeward Waters-Maui County Windward Waters-Oahu Leeward Waters-Oahu Windward Waters.
Gale Warning until 6 AM HST Friday for Alenuihaha Channel- Maalaea Bay-Pailolo Channel.
