Residents of the Hawaiian Islands can expect to see a continuation of the moderate trade winds over the next several days, with an uptick in breezy conditions setting in by the early week. A relatively dry and stable air mass hanging over the state is anticipated to limit the amount of windward showers for most islands until Friday. However, changes are on the horizon as a weak disturbance riding in from the east is set to grace the islands with increased cloudiness and shower activity, beginning Friday night and persisting into Sunday morning, the National Weather Service in Honolulu reports.
According to National Weather Service, a ridge of high pressure positioned far north of Hawaii is the force behind the upcoming weather pattern, serving to maintain moderate trade winds. Precipitation should remain lightweight over windward and mountain areas, while leeward locales are forecast to stay mostly dry through the end of the workweek. However, a weak trough expected to slowly approach from the east is about to gradually bolster the shower activity. These showers won’t amount to any flooding concerns, but they will present a welcomed bout of modest rainfall, especially along the east-facing slopes.
As for the Big Island and eastern Maui, the National Weather Service cautions that 1 to 2 inches of rain could concentrate along their windward slopes on Saturday. This comes after observing a blob of moisture near 150W, as indicated by the latest CIMSS MIMIC precipitable water imagery, with values hovering around 1.8 inches. Despite this, no significant flooding is anticipated; rather, the showers are seen as an opportunity to provide some beneficial rain.
The latter half of the weekend will illustrate an increase in shower activity for the state's western half, lasting until Sunday morning. Windward areas can expect a scattering of showers, while leeward regions are likely to experience a surge in cloud cover accompanied by occasional showers. A return to drier conditions is slated for Sunday afternoon, followed by a resurgence of trade winds predicted to not only grow breezier but to remain persistent through the first half of the next week. This resurgence foreshadows another plume of moisture anticipated to pass over Hawaii on Tuesday, once again sprinkling moderate showers across windward and mountain regions, with scattered precipitation possibly reaching leeward areas.
The aviation outlook remains mostly favorable, with the National Weather Service forecasting moderate to locally breezy trade winds to persist into the weekend, engendering predominantly VFR conditions, though windward and mauka areas might face brief stints of MVFR due to showers and low ceilings. Marine-wise, the state is poised under moderate easterly trade winds through Sunday, after which forecast models predict strengthened trade winds sufficient to prompt Small Craft Advisory conditions near Maui and the Big Island by Sunday evening, extending well into the following week.
Surf conditions along south-facing shores are expected to calm and remain below average through Friday before picking up slightly in subsequent days. East-facing shores will initially feature small, choppy conditions, which may intensify with the anticipated robust trade winds early next week. In a cautionary note, spring tides have peaked, and local tide gauges are signaling water levels around 1 foot higher than the Mean Higher High Water threshold at several locations. Consequently, a Coastal Flood Statement has been activated and will stay in effect throughout the weekend.
