Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
380 FXHW60 PHFO 061338 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 338 AM HST Sat Jul 6 2024 .SYNOPSIS... A stable moderate trade wind pattern with mainly light windward showers will prevail through Monday. Increasing trade winds and slightly wetter conditions are possible during the middle of next week, with breezy trades continuing into the weekend. && .DISCUSSION... Little change to the overall forecast philosophy overnight. The latest high-res models and early morning radar imagery show less in the way of showers this morning and through the rest of the weekend. In addition, the 12Z soundings from Hilo and Lihue show increasing stability across the state with inversion heights around 4500-5500 feet, about 1000 feet lower than yesterday at this time. Therefore, have trended PoPs and QPF down slightly to follow these trends. A surface ridge far north of the islands will maintain the current trade wind regime through the upcoming week. A developing surface high far northeast of the state will strengthen the local pressure gradient over the islands by the middle of next week, resulting in an increase to breezy trade wind speeds. A mid- to upper-level ridge over the islands will maintain the relatively dry and stable conditions through this weekend. Any showers that do reach the islands should only produce modest rainfall amounts and are expected to be focused over the windward slopes, with a few showers possible over the leeward slopes of the Big Island each afternoon. The GFS and ECMWF continue to show an increase in precipitable water reaching the islands Tuesday or so, although the focus has shifted a bit towards the southern end of the state. Expect a few more showers over the windward sides of the smaller islands, and a bit more of an uptick over windward Big Island. The increase in trade wind speeds during that time will allow some of those showers to reach some leeward areas at times. && .AVIATION... Moderate to locally breezy trade winds are expected through the rest of the weekend. Low cigs, SHRA and MVFR conds should favor windward and mauka areas, with some spillover into leeward areas. Otherwise conds should remain mainly VFR. No AIRMETs are currently in effect. && .MARINE... Gentle to locally fresh trades continue through Saturday, then become locally strong during the first half of next week. This will likely warrant a Small Craft Advisory for the typically windy zones around Maui County and the Big Island. Surf remains small along all shorelines through the forecast period. Mixed swell out of the southerly quadrant will maintain small surf along south-facing shores tonight and will maintain slightly perturbed conditions through much of next week. Likewise, small surf persists for northern exposures, although mixed swells out of the northerly quadrant may provide a small bump for the weekend. A short period NE swell will maintain small surf along east-facing shores even as background trade wind swell subsides. Choppy conditions then return as trades strengthen next week. 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 weekend mainly during afternoon peak high tide. Coastal Flood Conditions are borderline around Maui and the Coastal Flood Statement may be dropped there sooner than the Big Island coastal zones. && .HFO WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...TS AVIATION...SMW MARINE...JVC