


Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
420 FXHW60 PHFO 250200 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 400 PM HST Sun Aug 24 2025 .SYNOPSIS... Stable, mostly dry conditions will continue into the first half of the work week. Trade winds will veer slightly east southeasterly and weaken a bit into the moderate range. Trade wind showers will be few and far between. The one exception will be the Big Island, which could see increased showers over the Kona slopes through mid-week. More typical easterly trades look to return during the second half of this week. && .DISCUSSION... This afternoon, very dry conditions are prevailing across the main Hawaiian Islands. Ridging both at the surface and aloft northeast of the island chain is the main influence of weather across the region, maintaining persistent warm, stable, and dry conditions. Latest satellite imagery shows most areas are cloud and shower-free this afternoon, with the exception of daytime sea-breeze induced cloud buildups along the Kona slopes of the Big Island. There are also a few clouds over interior Kauai, which is located closer to a trough passing north of the state. Surface observations and an ASCAT pass show that wind speeds are generally in the moderate range with some locally breezy gusts. Little change is expected over the next few days. A low pressure system will push eastward across the north Pacific through Wednesday. As this occurs, a trough will allow the pressure gradient over the island chain to relax slightly. Wind speeds across the islands will follow suit, easing slightly when compared to those observed today, and veering east southeast. The lighter winds will also be conducive to sea-breeze development across terrain-sheltered areas. Model guidance continues to show a minor increase in moisture approaching from the southeast and passing across Big Island late Monday through Tuesday night. This moisture may enhance afternoon showers over the Kona slopes through mid-week. However, very dry air aloft across the remainder of state will remain firmly in place. Therefore, other than localized afternoon breeze activity, very few showers are expected, aside from brief terrain-enhanced windward upslope mauka showers. A new high far north-northeast of the state will become established during the second half of the week, allowing more typical easterly trade winds to return. && .AVIATION... Stable, moderate to breezy trades will continue to deliver clouds and showers to windward and mountain areas through the period, particularly overnight and during the early morning hours. Isolated MVFR will be possible within showers. Otherwise, VFR will prevail. No AIRMETs are in effect and none are anticipated to be needed through tomorrow. && .MARINE... High pressure north of the Hawaiian Islands maintains moderate to fresh trades through the week. Small swell energy emanating from the southerly quadrant slowly declines into Monday. A series of small longer period S swells then arrive by Tuesday providing a modest boost to S shore surf through Friday. Surf along N and W facing shores remains nearly flat while surf along E shores will remain characterized by short period chop. && .FIRE WEATHER... Elevated fire weather conditions will continue for the next couple of days due to the low relative humidity values. Very dry conditions were observed across the state today, with RH dropping into the 30s and 40s this afternoon. This is expected to be the case again through Tuesday with dry air remaining in place. Despite these dry conditions, however, marginal wind speeds have kept the need for Fire Weather headlines at bay. With the winds expected to ease further Monday through Tuesday, not anticipating the need for any fire weather headlines at this time. && .HFO WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Vaughan AVIATION...Farris MARINE...JVC FIRE WEATHER...Vaughan