Breezy trades will continue through the day as strong high pressure remains north of the islands, keeping showers focused mainly over windward and mauka areas. Trades are projected to gradually weaken later this week as an upper-level trough approaches from the west, leading to a subtle uptick of moisture across the islands. As the weak trough exits to the east, diminished cloud cover and drier conditions will return through the weekend. Light trades will continue through early next week, supporting development of localized land and sea breezes at times. Isolated to locally scattered showers will persist favoring windward and mauka locations.
A broad surface high pressure ridge anchored well north of the Hawaiian islands will remain the dominant weather influence the next couple of days. This pattern will support continued breezy trades and maintain periodic showers focused over windward and mauka areas. However, a weak upper-level low and associated trough approaching from the west will gradually meander over the state by tomorrow. As this occurs, trades are expected to temporarily weaken, with a subtle uptick of moisture across the islands leading to a modest increase in cloud cover and shower activity through the morning. This will be short-lived, though, as the trough is expected to exit as quickly as it arrived. The passing upper-level trough will weaken the strong pressure gradient associated with the surface high. Consequently, windward areas will experience lighter winds, creating potential for localized land and sea breeze developments across the rest of the islands heading into the weekend.
By late weekend, a surface low tracking southward from the Aleutians is forecast to split the broad surface high north of the islands, further suppressing the trades. Although trades are expected to remain on the lighter side, they should still provide sufficient airflow to help cap afternoon humidity levels statewide. Trades are expected to gradually recover by midweek next week. This return to the standard trade regime will reintroduce isolated to locally scattered showers, primarily favoring windward and mauka areas through the rest of the forecast period. However, June is typically climatologically drier, so any shower activity will remain limited within the broader dry seasonal regime.
Trades will continue to gradually trend downward over the course of the week as a stable weather pattern remains in place over the islands. Isolated showers cannot be ruled out for windward sites, however VFR conditions are widely anticipated.
AIRMET Tango remains in effect across all islands down mountain for moderate turbulence due to breezy trades, however as winds scale back in intensity, its possible that this AIRMET may be cancelled within the next 24-48 hours.
Breezy to strong trade winds are on a slow decline as a weakness develops within the ridge to the north of the islands. Trades will continue ease through the weekend. The Small Craft Advisory for the waters near Maui County and the Big Island has been extended through tonight as the latest guidance suggests winds may stay elevated just a bit longer than originally anticipated. A more significant weakening of the trade winds is likely this weekend into early next week as a large North Pacific low pressure system far north of the islands breaks the ridge down even further.
The current small, long-period northwest swell appears to have peaked late yesterday afternoon, and has been very slowly subsiding overnight. Expecting north- and west-facing surf to continue to gradually subside into the weekend.
A series of medium-period south swells will continue to bring small surf to south facing shores today. Some readings from buoy 51002 suggest some of those swells could be a little larger than originally anticipating. A more significant long-period south swell is expected to begin filling in tonight and will likely bring above- advisory- level surf to south- facing shores Friday and into the weekend. This swell originated from a storm- force low that passed south and east of New Zealand over the weekend, generating seas of 35 to 40 feet or greater within Hawaii’s swell window, though the peak of the energy may pass just east of the state. The buoys near American Samoa picked up a portion of this swell today, seeming to peak around 5 feet 16 seconds, with the peak of the swell also likely passing to their east. Elevated surf along south-facing shores will likely continue into the first week of June due to a continued active weather pattern near New Zealand sending swells toward Hawaii.
Rough surf along east-facing shores will gradually lower through the weekend as trade winds ease.
Small Craft Advisory until 6 AM HST Friday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters.
