Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
050 FXHW60 PHFO 020131 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 331 PM HST Fri Aug 1 2025 .SYNOPSIS... Breezy to locally windy trades and rather dry and stable conditions will continue through Saturday. Clouds and light showers will be focused over windward and mauka areas, while most leeward areas remain dry. Stable trade winds will gradually ease Sunday through Tuesday and may become disrupted Wednesday or Thursday. && .DISCUSSION... A gusty, stable, and rather dry trade wind flow will persist through Saturday. The trades will remain breezy to locally windy as the local pressure gradient remains tight, due to surface high pressure drifting eastward about 1,000 miles north of the state and a trough moving westward in the deep tropics south of the islands. High pressure aloft will maintain an inversion between 5,000 to 6,000 feet, and the resulting stability will continue to produce localized strong winds near terrain across the Kohala Districts of the Big Island and the central valley of Maui, where the Wind Advisory has been extended through Saturday afternoon. Shallow pockets of moisture being carried in on the trade wind flow will continue to bring light rainfall accumulation mainly to windward slopes, with leeward areas remaining dry. Trade winds will gradually decline Sunday into Tuesday as the high drifts eastward and the local pressure gradient slowly relaxes. The stable pattern of mainly windward and mauka showers, essentially typical August rainfall, should persist as little organized moisture is depicted in the guidance. Trades will likely become disrupted Wednesday or Thursday, though there is uncertainty in the details. The latest National Hurricane Center forecast depicts current east Pacific Tropical Storm Gil weakening to a remnant low well east of Hawaii early next week, and the GFS and ECMWF show a remnant circulation passing north or near the state as early as Wednesday but potentially Thursday. Disrupted trades is the most likely scenario, but it`s too early to know if there will be any significant chance for enhanced rainfall. && .AVIATION... High pressure far north and northeast of the islands, combined with a low pressure system to the southwest, will maintain breezy to windy trade winds into the weekend. VFR conditions are expected to prevail, however some passing showers could bring brief MVFR conditions mainly to windward and mountain areas, especially overnight and in the early morning hours. AIRMET Tango is in effect for moderate with isolated severe turbulence over and immediately S through W of the island mountains due to strong trade winds and gusts. && .MARINE... High pressure will remain far north of the state this weekend and help generate fresh to locally strong trades across the local waters. A Small Craft Advisory (SCA) has been extended through tomorrow for most marine zones surrounding Maui and the Big Island, then limited to the typical windier zones through Sunday. Trades then begin to weaken by early next week as the aforementioned high drifts further east. The current south swell has been holding steady all day at the buoys bringing a steady supply of advisory level surf to south facing shores. As such, a High Surf Advisory remains in effect for the south facing shores of all islands through 6 AM HST Saturday morning. This south swell will gradually decline tonight through the weekend, then another south swell should arrive late Sunday into Monday and help build surf heights to near advisory levels once again early next week. East shore surf will remain elevated and choppy due to locally strong trade winds through this weekend. This will be followed by a decline early next week as trades weaken. Nearly flat summer conditions along north facing shores may be interrupted late this weekend by a small long period northwest swell from Typhoon Krosa, currently in the western Pacific. && .HFO WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 6 PM HST Saturday for Niihau-Kauai South- Kauai Southwest-East Honolulu-Honolulu Metro-Ewa Plain-Waianae Coast-Oahu North Shore-Central Oahu-Waianae Mountains-Molokai North-Molokai West-Molokai Leeward South-Lanai Windward-Lanai Leeward-Lanai South-Lanai Mauka-Kahoolawe-Maui Leeward West-Maui Central Valley North-Maui Central Valley South-South Maui/Upcountry-South Haleakala-Big Island South-Big Island Southeast-Kohala-Big Island Interior. High Surf Advisory until 6 AM HST Saturday for Niihau-Kauai Leeward-Waianae Coast-Kahoolawe-Maui Leeward West-Kona-Kauai South-East Honolulu-Honolulu Metro-Ewa Plain-Molokai Southeast- Molokai Leeward South-Lanai Leeward-Lanai South-Maui Central Valley South-Kipahulu-South Maui/Upcountry-South Haleakala-Big Island South-Big Island Southeast. Wind Advisory until 6 PM HST Saturday for Kohala-Maui Central Valley North-Maui Central Valley South-Big Island North. Small Craft Advisory until 6 PM HST Saturday for Kaiwi Channel- Maui County Windward Waters-Big Island Windward Waters. Small Craft Advisory until 6 PM HST Sunday for Maalaea Bay- Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Wroe AVIATION...Foster MARINE...Farris FIRE WEATHER...WROE