Moderate easterly trade winds will persist today, with clouds and light showers favoring windward and mauka areas during the early morning hours. Trades will ease Tuesday as the surface ridge weakens, bringing a transition to light winds, increasing humidity, and land and sea breeze conditions through Thursday. Showers will remain brief and mainly over interior and leeward areas during the afternoons. Rainfall chances may increase by next weekend as an upper disturbance and a weak front approach the islands.
Moderate easterly trades will remain in place today, with low clouds and a few light showers focused over windward and mauka areas. Leeward areas will remain mostly dry, with only isolated passing showers possible.
Beginning Tuesday, the ridge north of the islands will weaken in response to a series of cold fronts passing well north of the state. This will lead to a gradual easing of the trade winds, with local land and sea breeze circulations becoming more dominant through midweek. From Tuesday through Thursday, a more humid air mass will settle over the islands, with dewpoints potentially climbing into the mid- to upper-60s. These dewpoints combined with the afternoon sea breezes will support localized afternoon cloud buildups and a few brief showers over interior and leeward areas, followed by clearing at night as land breezes develop.
By the latter part of the week into the weekend, moisture and rainfall chances may trend up. Global guidance indicates upper heights lowering as an upper-level disturbance approaches the region. In addition, a weak attendant frontal boundary may move into the area. However, there remains considerable spread among the model solutions regarding the timing and strength of these features, so confidence in the details remains limited at this time.
Moderate trades continue, with clouds and brief showers expected over windward sites. Periods of MVFR ceilings and visibility are possible in showers, otherwise widespread VFR is expected. Trades are expected to gradually weaken through the midweek.
AIRMET SIERRA is in effect for northern Oahu due to clouds and showers, however conditions are expected to improve by daybreak.
Moderate to locally fresh trade winds will be in place today and then weaken to land/sea breezes Tuesday and Wednesday as a front to the northwest passes by to the north and weakens the ridge. Gentle to moderate trade winds are expected to redevelop Thursday and Friday before another front passes by to the north this weekend and make winds light and variable.
A moderate northwest swell coming in a little below guidance will build today and produce surf above seasonal average during the peak tonight and early Tuesday. This swell will slowly decline late Tuesday and Wednesday. A larger northwest swell could produce surf near the High Surf Advisory level Thursday, then lower Friday into next weekend.
A south-southwest swell will gradually decrease today and Tuesday, with small pulses keeping surf from going flat for the later half of the week.
Trade wind swell will lower below seasonal average today and will remain small through the remainder of the week.
None.
