Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
168 FXHW60 PHFO 221306 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 306 AM HST Sat Nov 22 2025 .SYNOPSIS... Light to moderate trades persist through the weekend, easing thereafter for the remainder of the outlook period. Showers will remain predominately over windward and mauka areas. An upper-level shortwave moves into the area Sunday and may enhance shower coverage to leeward and interior terrain. Weather will trend wetter as the week progresses as weak troughs north of the Hawaiian Islands rig up moisture laden southerly air across the state. && .DISCUSSION... Broad area of high pressure resides northeast of the islands will help produce a pressure gradient strong enough to maintain light to moderate trades through the weekend. The trades gradually ease thereafter, persisting through the remainder of the outlook period, sustaining a typical windward and mauka shower pattern. Latest model guidance remains in strong agreement depicting a quick moving upper-level shortwave propagating in the vicinity of the area Sunday, bringing a brief period of instability. While this does not appear to have a significant impact to the Hawaiian weather, only producing some enhanced showers within the offshore northeast of the islands. However, under a weakened trade regime, it may trigger a few afternoon showers across more leeward and interior terrain, as well as increase cloud coverage throughout the day. Weak high pressure swiftly builds in the wake of the quick moving shortwave, providing some sort of stability and maintaining trades across the islands. Apart from subtle fluctuations, this will be the general trend through the first half of next week. Model guidance begins to show some heartburn thereafter with several discrepancies between the models related to the potential for another upper-level trough descending onto the islands around Thanksgiving Day. Given the inconsistencies between the models with regards to the timing and location of the aforementioned upper-level trough, confidence remains low, especially in the sense of potential impacts -- if any -- that may come to the island. For now, future shifts will be needed to monitor model trends to increase said confidence. && .AVIATION... Light to moderate trades persist through the weekend, easing gradually through the remainder of the period. Brief periods of showers will predominately focus on windward and mauka areas resulting in occasional MVFR conditions where lowered ceilings and visibilities will be possible. Otherwise, VFR conditions prevail. No AIRMETs are in effect, however, light icing continues this morning for Maui and Big Island for layers 160-210 through 2100z. && .MARINE... High pressure far to the northeast will weaken over the weekend as a front also weakens north of the waters. Fresh to locally strong trade winds will persist through the day before gradually easing through the forecast period. A Small Craft Advisory (SCA) has been extended for the windier waters and channels around Maui County and the Big Island through this afternoon. A new high pressure building in north of the waters this Sunday will continue to move east and keep trade winds in the gentle to moderate range Sunday into next week. Another front moving across the north Pacific next week will push a ridge near the islands and keep the gentle to moderate trade winds through the forecast period. The current northwest swell will maintain surf at moderate levels along north and west facing shores through the morning hours. A new northwest swell is expected to build later this afternoon and peak tonight into Sunday, then decline through early next week. Long period forerunners have started to reach the offshore NDBC buoy 51101. A High Surf Advisory (HSA) has been issued for select north and west facing shores starting at noon today through Sunday afternoon. A potentially larger northwest swell is expected around the middle of next week. Stay tuned for more details as the low continues to develop to the far northwest of the islands. As trade winds slowly weaken, choppy surf along east facing shores will decline into early next week. Surf looks to remain tiny to small through the forecast period with tiny background southerly energy. && .FIRE WEATHER... Critical fire weather conditions are not expected through the forecast period. Relative humidity levels decrease throughout the period, however, wind speeds remain below critical fire weather thresholds. Temperature inversion heights this morning range from 6,000 to 7,000 feet. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Advisory from noon today to 6 PM HST Sunday for Niihau- Kauai Leeward-Waianae Coast-Oahu North Shore-Maui Windward West- Kauai North-Molokai Windward-Molokai North-Molokai West-Maui Central Valley North-Windward Haleakala. Small Craft Advisory until 6 PM HST this evening for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Pierce AVIATION...Pierce MARINE...Shigesato FIRE WEATHER...Pierce