Trade winds will weaken and veer southeasterly tonight and Friday as a front approaches from the west. Fairly dry conditions will prevail during the next couple days, with light showers limited primarily to windward and mauka areas. Increasing rain chances Sunday and Monday as the system weakens near Hawaii with a return to trades by midweek.
High pressure far north of the area driving moderate trades across the state this afternoon. Visible satellite shows mostly cloudy skies windward and partly cloudy skies leeward, with little precipitation picked up on radar.
A weakening front will approach the islands from the west through Saturday, easing the trades and shifting boundary layer winds around to the east-southeast. A period of rather dry weather is expected to persist across the islands through Saturday, as the deeper moisture associated with the front will remain to the west and northwest of the state.
The operational GFS and ECMWF, there ensembles, and AI versions are remain split on the handling of the pattern evolution Sunday into early next week. Roughly half support keeping the deeper moisture west and south of the state, while the other half indicate the deeper moisture moving into at least the western islands. Overall, will take a blended forecast approach, showing an increase in rain chances mainly over the western islands Sunday and Monday, with a transition back to a breezy trade wind pattern Tuesday through the middle of next week.
Moderate to breezy trade winds will continue to prevail across the island chain through tonight, with only a few light showers favoring windward and mountain locations. VFR flight conditions will prevail for most locations.
A weakening front will approach the islands from the west Friday into Saturday, and this will ease trade winds and veer them to become more southeasterly. Relatively dry conditions will continue, as the deeper moisture associated with the front remains west of the state for the next couple of days.
There are currently no AIRMETs, and none are anticipated through tonight.
The current north-northeast swell has continued to decrease today, leading to a diminished threat of harbor surge in north- facing harbors and the associated Marine Weather Statement has been allowed to expire. Trade winds also continue to diminish, which in combination with the decreasing swell, have allowed surf along east-facing shores to fall below advisory criteria this afternoon. Therefore, the High Surf Advisory has been allowed to expire as well.
Though winds are trending down, favored channels and windy areas around Hawaii and Maui Counties will linger at Small Craft Advisory criteria tonight. Trade winds veer out of the southeast on Friday as a cold front approaches and moves into the area through the weekend. This will allow localized land and sea breeze conditions to develop near the coasts over the weekend.
A fresh, short- to medium-period north-northeast swell from a gale centered around 1200 nautical miles northeast of the state is forecast to arrive over the weekend. This new swell will support small surf along exposed coasts through the weekend and into Monday. Short-period, choppy conditions are expected to return by midweek as fresh trade winds redevelop and expand upstream of the state.
Surf along north- and west-facing shores will trend upward beginning Saturday as a fresh west-northwest swell arrives from a gale located around 1500 nautical miles northwest of the state, south of the Aleutians near the Date Line. This swell will peak early next week before gradually lowering into midweek.
Surf along south-facing shores will remain near the seasonal average into March but could trend up in the long range, possibly by the second week of March, due to a potential gale passing within our swell window south to southeast of New Zealand over the weekend.
Small Craft Advisory until 6 AM HST Friday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters.
