Surface high pressure northwest of the Hawaiian Islands will slowly slide east over the next several days. Passing showers are possible over windward and mauka areas during this time period, mainly during the overnight to early morning hours. The next best chance for statewide rainfall should arrive Tuesday and Wednesday as increased low level moisture arrives with an old cold front drifting into the region.
Trade winds will continue with brief periods of passing showers over windward and mountain areas favoring the overnight to early morning hours. Improving weather trends during the daylight hours.
AIRMET Sierra is in effect for mountain obscurations over north and east sections of Kauai, Oahu, Molokai, and Maui. Low clouds and scattered windward showers will maintain obscured terrain in this area.
AIRMET Tango remains in effect for low level moderate turbulence over and downwind of island mountains.
Fresh to locally strong trade winds will increase tonight as a strong 1033 mb high builds far north of the islands. A Small Craft Advisory (SCA) remains in effect for the typically windy waters around Big Island and Maui today, then expands to all waters tonight as trades strengthen. Winds will diminish somewhat late Sunday and Monday as the high moves to the northeast, but a new north swell will push combined seas above 10 feet for exposed waters, likely prompting an extension of the SCA for most zones. Expect moderate to locally strong trade winds to require a SCA for the typically windy waters Tuesday through the remainder of the week.
A small north-northwest swell will hold through tonight, followed by a moderate, long-period north swell building on Sunday. The north swell (350 to 010 degrees) will produce surf near the High Surf Advisory levels along north-facing shores, as well as some exposed eastern shores, Sunday afternoon into Monday morning. The north swell will gradually decline late Monday through Wednesday. A tiny pulse of northwest swell will be possible late next week, followed a moderate swell next weekend.
Rough surf along east-facing shores will remain above seasonal average over the next few days due to elevated trade wind swell and some wrapping north swell. East shore surf is expected to be around seasonal average Tuesday through the rest of the week. Mainly small background level surf will persist along south-facing shores through much of the week, though a small long-period swell will be possible on Friday.
Small Craft Advisory from 6 PM this evening to 6 AM HST Sunday for 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.
Small Craft Advisory until 6 AM HST Sunday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.
