Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
011 FXHW60 PHFO 191928 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 928 AM HST Sat Oct 19 2024 .SYNOPSIS... Moderate to breezy trades will return today through Sunday, with clouds and showers favoring windward and mauka locations. Trades will ease into the light to gentle range Monday through Tuesday, then increase slightly through the remainder of the week. && .DISCUSSION... The latest surface analysis shows a ridge north of the state, weakened due to a cold front passing by farther to the north. This pattern has caused the trades to ease locally over the past couple of days, allowing localized land and sea breeze conditions to become established over the western end of the state. A return to more stable conditions is already evident on the Hilo sounding from early this morning, with more extensive drying and warming in the mid-levels and a lower inversion height than the same time yesterday. This trend will continue through the weekend, along with a return to breezy trades, as mid and upper heights rise and the surface ridge strengthens through the weekend. The increased stability will keep rainfall totals limited, with the best shower chances favoring windward and mauka areas. A pattern transition is expected next week due to two broad gale lows forecast to form far northwest and northeast of the state. The surface ridge will weaken in response, allowing the trades to taper back into the light to gentle range and land/sea breezes to occur. Global models are keeping most of the weather associated with these systems far west and north-northeast of the area, so mostly dry conditions should persist locally. Shower activity will be mainly light and focused on windward slopes, as well as over leeward areas in the afternoons where localized sea breezes develop. && .AVIATION... A ridge to the north of the islands will continue to bring light to moderate easterly trade winds to the region. Expect winds to trend upwards through tomorrow, with clouds and showers generally favoring windward and mountain areas. Overall, VFR conditions should prevail with brief MVFR conditions possible in showers. No AIRMETs are in effect, and none are expected today. && .MARINE... Fresh to locally strong trade winds will continue through the weekend. Winds will taper off beginning Monday as low pressure systems develop to the northeast and northwest of Hawaii. The northwest low will linger through much of next week keeping winds gentle to moderate out of the east southeast. A small, short-period north to northwest swell will gradually diminish this weekend and early next week, shifting to a more northeasterly direction by midweek. North facing shores will see the surf from the swell then shifting to east facing shores as the direction changes. Elsewhere, background south swell will keep surf from going flat along south shores. A small, long-period reinforcement is expected to arrive Monday night and decline through the week followed by another on Friday. A Coastal Flood Statement (CFWHFO) for all coastal zones is highlighting the fact that higher than forecast water levels are combining with full moon high tides, bringing the potential for minor coastal flooding, mainly during the early morning hours. && .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...TS AVIATION...M Ballard MARINE...Foster