Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
397 FXHW60 PHFO 120153 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 353 PM HST Thu Jul 11 2024 .SYNOPSIS... Strong trade winds will persist, delivering abundant low clouds to most areas through Friday, while associated brief showers over windward areas will spread to leeward areas on Oahu this evening. Fewer leeward clouds are expected over the weekend, while the Kona slopes will receive their typical summertime afternoon and evening clouds and showers. && .DISCUSSION... Breezy to windy trades will prevail into next week, supported by a persistent surface ridge far N of the islands. The ENE trade winds will deliver abundant patches of low clouds to windward areas in the short term (and occasionally leeward on the smaller islands), while associated brief showers will mainly fall over windward areas. The Kona slopes will receive their typical summertime afternoon and evening clouds and showers. A westward-moving mid-level trough just E of the area is also noted at 700 mb, and is responsible for some weakening of the low-level subsidence inversion. Clouds and showers are maximized immediately upstream of Oahu, where a wet evening is expected, with an ample amount of showers spreading leeward. Meanwhile, a relatively dry evening is expected over the Big Island and Maui, with showers likely increasing late over Kauai. The mid-level trough will dissipate Friday night and Saturday, and the inversion base should lower enough to allow for more leeward sunshine over the weekend and into next week. Otherwise, randomly distributed clusters of stable and showery low clouds will periodically move through, modulating sky and shower coverage as they do so, mainly windward. && .AVIATION... Breezy to windy trades will continue for the next couple of days, with passing showers favoring windward and mauka areas. Expect mainly VFR, with brief MVFR in showers/low clouds. An area of enhanced showers is currently aligned with Oahu, keeping periodic MVFR conditions there. Therefore, AIRMET Sierra for tempo mountain obscuration remains in effect for windward areas of Oahu. Conditions have improved elsewhere for now. AIRMET Tango for low-level turbulence in the lee of island terrain will remain in effect for the next several days due to the strong trades. && .MARINE... Persistent high pressure will remain in place north of the state through the weekend and into early next week. This will allow strong to near gale force trade winds to continue across the island chain, with only subtle day-to-day fluctuations. The Small Craft Advisory (SCA) has been extended through Saturday afternoon for all Hawaiian waters, but this may need to be extended again into early next week. The strong trades could ease slightly during the second half of next week as the ridge weakens. Surf along east facing shores will remain rough through early next week due to the strong trades locally and upstream of the state. A downward trend is possible next week as the upstream fetch weakens and the local trades begin to ease around midweek. Surf along south facing shores will remain elevated as overlapping south-southwest swells move through. A fresh south- southwest pulse arriving Friday will result in an upward trend in surf going into the weekend. A more significant south swell will gradually fill in late Saturday night into Sunday, then likely reach the advisory level late Sunday through Monday. A gradual downward trend is expected Tuesday through midweek. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 PM HST Saturday for all Hawaiian waters. && $$ DISCUSSION...Birchard MARINE...Vaughan AVIATION...TS