


Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
525 FXHW60 PHFO 041334 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 334 AM HST Fri Apr 4 2025 .SYNOPSIS... A dissipating front has stalled out over the Kauai Channel today. Expect continued wet weather across Kauai County during this time, with periods of enhanced showers moving into Oahu. Trade winds will begin to build back into the islands today, strengthening into the moderate to breezy range from Saturday onward, with periods of enhanced showers lasting through much of next week. && .DISCUSSION... Looking into the satellite imagery this morning, we see the forward motion with the dissipating frontal boundary has stalled over the Kauai Channel today as winds behind the front are no longer driving the system eastward. Northeasterly to easterly trade winds will bleed through the front today spreading trade winds across the state through the day. Enhanced showers will favor windward and mountain areas of Kauai and to a lesser degree Oahu in this pattern. Easterly trade winds building in will begin to push this remnant frontal boundary back westward over Kauai later tonight into Saturday. Vog will continue to linger over most islands through much of the day until the easterly trade winds begin to push the Vog plume in a more westward direction away from the smaller islands later tonight. Areas near and west of the Kilauea Volcano on the Big Island will continue to see Vog impacts through the week. Elsewhere more typical easterly moderate to locally breezy trade wind weather will return to the islands from Saturday onward. The forecast next week continues to show a high confidence of an easterly moderate to locally breezy trade wind weather pattern taking shape. drifts into the islands from the north. This cloud band is associated with the remnants of a dissipated cold frontal band originating in the eastern Pacific. Enhanced showers next week will favor windward and mountain areas during the Tuesday through next Friday time period. Higher chances for showers are likely over windward and mountain slopes during the typical overnight to early morning hours. && .AVIATION... A dissipating front over the western end of the state will stall today with northeasterly trade winds strengthening over the state from the west. Enhanced clouds and showers over Kauai and Oahu are expected through the morning as moisture lingers along the front. Periods of MVFR conditions are likely within the heavier showers. The eastern half of the state will see moderate to locally breezy southeasterly winds through the afternoon before easterly trade winds return tonight. Localized land breezes in sheltered areas are expected but overall, VFR conditions will prevail. AIRMET Sierra is in effect for mtn obsc for all of Kauai and Oahu. This could continue through the morning as clouds and showers linger. AIRMET Tango is in effect for tempo moderate upper level turbulence and is expected to continue through the morning. Most areas could continue to see some Vog due to the ongoing eruption of Kilauea. However, Vog is not expected to impact visibilities enough to warrant a mention in any TAF. && .MARINE... A dissipating front has stalled over the Kauai Channel and will continue to diminish through the day. Moderate to locally strong north to northeast winds will develop around Kauai waters today, while gentle to moderate east to southeast winds back to a more easterly direction elsewhere. A Small Craft Advisory (SCA) has been issued through tonight for waters around Kauai. The SCA will likely need to be expanded and extended into early next week as a large swell moves through the state Saturday, elevating seas across the state. In addition, moderate to locally strong trades winds are expected to reestablish across state as a strong high builds north of the area. A moderate, medium period north northwest swell (330-340) will continue to fill in today. Surf along north and west facing shores will peak near or just above advisory level later today. So far offshore and near shore buoys remain in-line with model guidance, but will continue to monitor to see if the swell comes in a little larger than anticipated which may warrant a High Surf Advisory. A large to extra large, long period swell (350-360) is still on track to quickly build in Saturday on already elevated seas, producing warning level surf along north facing shores with advisory level surf across west and east facing shores that will continue through the weekend. This swell, aside from being hazardous to small craft, could generate harbor surges along north facing bays and inlets. Surf along south facing shores will remain tiny into the weekend with mainly background energy dominating. A small, long period south swell could fill in later over the weekend into early next week and provide a small boost to surf along south facing shores. Surf along east facing shores will gradually build today and Saturday with the return of trade wind flow over and upstream of the state. East shore surf will also get a boost from the larger northerly swells wrapping into exposed areas. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 AM HST Saturday for Kauai Northwest Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel. && $$ DISCUSSION...Bohlin AVIATION...Shigesato MARINE...Almanza