Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
851 FXHW60 PHFO 232015 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 1015 AM HST Sat Nov 23 2024 .SYNOPSIS... Light winds and mostly dry weather will prevail for at least the next couple of days, but a weak front moving over the islands will bring a chance of showers Sunday afternoon through Monday, mainly to windward portions of Kauai and Oahu. Dry weather will persist after the front dissipates by Tuesday, with light winds likely allowing land and sea breezes to develop over land. && .DISCUSSION... Light winds and mostly dry weather will prevail this coming week, with a couple of exceptions. A weak front moving over the islands from the N will bring a chance of showers Sunday afternoon through Monday, mainly to N and E facing slopes and coasts of Kauai and Oahu, with a return to dry weather thereafter. Except for the chance of an increase in trade winds around the middle of the week, a nearby surface ridge will keep winds light. After another 24 hours or so of light and variable winds and essentially zero rainfall, a relatively weak high building NW of the islands will push a weak frontal boundary over the islands. This front will bring an increase in low-level moisture that will likely fuel some light showers. The high and associated nearby ridge will support light N to NE winds as the front gradually dissipates through Tuesday, with land and sea breezes in sheltered areas on land. Strengthening ENE trade winds may reach moderate levels around mid- week when the high moves to a position NE of the islands, but confidence is low, with trade winds potentially diminishing by the end of the week. Limited (windward) to no (leeward) rainfall is expected after the front dissipates. && .AVIATION... Light winds with sea/land breezes are expected today and tonight. VFR conditions should prevail, with some isolated MVFR cigs and light showers possible over windward Big Island this afternoon. No AIRMETs are currently in effect. AIRMET Tango may be required for moderate upper level turbulence around 30 kft tonight. && .MARINE... Surface ridge just north of the waters will promote light to gentle winds through the first half of next week. A weak front is forecasted to approach the far northwest coastal waters Sunday morning and dissipate as it moves over the western coastal waters Monday and Tuesday. Scattered showers are expected preceding the frontal passage with gentle northerly winds behind the front. Light to moderate trade winds will build in for the second half of next week as the surface ridge sets up to the north of the waters. Surf along north facing shores will remain moderate through the morning as the current moderate, medium period north- northeast swell will slowly trend more easterly today and slowly decline tonight and Sunday. A Marine Weather Statement is in effect for light harbor surges, particularly at Hilo and Kahului harbor through today. Long period forerunners from the northwest have begun to show up along nearshore buoys and is expected to continue to fill in through the afternoon and peak Sunday. At the peak of the swell, it is forecasted to be just below the High Surf Advisory criteria for north and west facing shores. Surf along east facings shores will remain small except shorelines exposed to the north-northeast swell through the first half of the week. Surf along south facing shores will remain tiny through the first half of next week with mainly background energy. && .FIRE WEATHER... KBDI values remain elevated across leeward areas, and no significant leeward rainfall is anticipated for at least the next several days. Relative humidity values may approach the critical 45% threshold during the late morning and afternoon hours as a relatively dry air mass remains in place. However, light winds will prevent critical fire weather conditions from developing. && .HFO WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION/FIRE WEATHER...Birchard AVIATION...Jelsema MARINE...Shigesato