Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
005 FXHW60 PHFO 070638 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 838 PM HST Sat Jul 6 2024 .SYNOPSIS... A stable, moderate trade wind pattern will prevail through Monday with light showers focused over the windward and mountain areas. Increasing trade winds, and slightly wetter conditions, are possible during the middle of the week, with breezy trades continuing into next weekend. && .DISCUSSION... No changes to the forecast this evening, and only expecting minor tweaks to the forecast with the morning package to keep the forecast aligned with the latest runs of the models. Rainfall totals have remained low across the islands as expected with the stable airmass overhead. Moderate trades continue to focus clouds, and the limited showers, to the windward sides of the islands. Clouds formed over the leeward slopes of the Big Island, but as with the windward slopes, limited rainfall. A ridge far northeast will build and extend to the west setting up north of the islands over the next few days. This will lead to a gradual increase in the trades Monday and Tuesday. A stable airmass in the upper levels will maintain the relatively dry conditions through the remainder of the weekend. The GFS and ECMWF both agree with a pool of moisture riding in on the trades Monday and Tuesday which will boost shower activity some. Further strengthening of the ridge to the north during the middle part of the week will lead to an additional uptick to the trades. The GFS shows more of an increase in shower activity from midweek to the end of the week than the ECMWF. Will likely tweak the forecast for the morning package for the second half the week to trend towards a blend of the forecast. && .AVIATION... Moderate to locally breezy trade winds are expected to continue through the rest of the weekend. Brief periods of MVFR conditions with clouds and passing showers will be possible, mainly over windward and mauka areas. Otherwise VFR conditions are expected to prevail. No AIRMETs are currently in effect. && .MARINE... High pressure far northeast of the state will keep gentle to locally fresh trade winds into Monday. The ridge to the north looks to strengthen early next week and bring back moderate to locally strong trade winds. A Small Craft Advisory will likely go back up for the typical windy waters around Maui County and the Big Island. Small surf will hold along south facing shores over the next few days as the current small south- southeast swell will hold through the weekend before a south- southwest swell will build in Monday and maintain small surf through the first half of next week. Into the long range, a moderate long period south southwest swell is expected towards the end of next week as a strong low in the southwest pacific continues to develop. Surf along north facing shores will remain tiny as a northeast swell has started to fill in this evening. Surf along east facing shores will trend up over the next few days as trade winds strengthen across the region. The combination of higher than normal water levels and afternoon spring tides are resulting in water levels running over half a foot above guidance around the Big Island and Maui. This will cause minor coastal flooding issues for both Big Island and Maui into the evening and again on Sunday afternoon during peak high tide. && .HFO WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...M Ballard AVIATION...Farris MARINE...Shigesato