FXHW60 PHFO 141938 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 938 AM HST Sat Dec 14 2024 .SYNOPSIS... High pressure far to the north and northeast of Hawaii will drive breezy trade winds through the weekend. A slight increase in windward showers tonight into Sunday. Light winds are expected through the first half of next week as a front approaches. This front will move through Thursday with some showers along the frontal band. && .DISCUSSION... High pressure far to the north and northeast of Hawaii will drive breezy trade winds through the weekend. Visible satellite shows scattered low clouds and isolated showers moving east to west across the state. 12Z soundings show a strong inversion around 6 kft with a fairly dry 1.1 inch precipitable water. Plenty of dry air aloft from a broad upper ridge over and just north of the state. These stable conditions will keep rainfall pretty minimal today. Tonight into Sunday, a weak upper trough will graze past the northeast side of Hawaii and may bring some cloud and shower enhancement. Any showers that do occur will focus over windward and mauka areas. Trade winds will weaken to a light and variable pattern from Monday through Wednesday as a cold front approaches the state from the northwest. This lighter flow will allow for the development of land and sea breezes and limited shower activity over interior and leeward areas each afternoon and land breezes helping to clear out cloud cover overnight. Current model guidance suggests that the cold front will move into Hawaii during the second half of next week as it weakens. Rainfall amounts do not appear to be very significant, and will be brief as the front quickly moves through. Winds will strengthen out of the north behind the front around Thursday and eventually veer to the northeast by Friday. && .AVIATION... Breezy trades continue through tonight, easing slightly on Sunday. Clouds and showers will tend to focus windward and mauka with patchy MVFR expected tonight and early Sunday morning, but VFR is forecast to prevail. AIRMET Tango remains in effect for lee turb. AIRMET Tango may be needed for moderate upper turb over the western half of the state tonight. && .MARINE... Fresh to strong easterly trade winds will prevail through Sunday, easing Sunday night into early next week as the ridge weakens and shifts south due to a series of cold fronts passing to the north. Small Craft Advisory remains in place through the weekend over the the windier channels and waters around Maui County and the Big Island. Starting late Sunday night, the trades will quickly ease, likely enough for overnight and early morning land breezes and daytime sea breezes. This pattern will persist through the first half of next week as the background flow shifts southeast Sunday night into Monday, then south to southwest Tuesday through midweek as a cold front approaches. Surf along exposed north and west-facing shores will gradually ease over the weekend as the swell that filled in Friday moves out. By Tuesday, surf will begin to rise again, with a significant upward trend anticipated through the second half of next week. This increase will be driven by a decent-sized fetch developing over the far northwest Pacific, near the Aleutians from the Date Line to the Kuril Islands. Heights could exceed warning-levels late next week if conditions evolve as projected. Surf along east-facing shores will remain rough through the weekend but will gradually decrease late Sunday and into much of next week as the trade winds diminish. Surf along south-facing shores will remain near seasonal averages, influenced by a mix of short-period southeast swells and occasional longer-period background south-southwest swells. Peak monthly tides combined with water levels running higher than predicted could lead to minor coastal flooding issues for vulnerable low-lying coastal areas. The best chance for these impacts will occur during the early morning high tides between midnight and daybreak through the weekend && .FIRE WEATHER... Critical fire weather conditions are not expected for the next seven days. Relatively dry conditions will persist statewide through Wednesday. A weakening cold front may drift into the western islands from Thursday to Friday, briefly increasing shower activity especially over the western half of the state. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 PM HST Sunday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION/FIRE WEATHER...Foster AVIATION...JVC MARINE...Kino