Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
878 FXHW60 PHFO 170305 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 505 PM HST Sun Aug 16 2026 .SYNOPSIS... Tropical Storm Lala is moving away to the west but will continue to affect the west end of the state . Areas of damaging winds may persist, mainly across Kauai County, and the threat of heavy flooding rainfall will continue on most islands. As Lala moves west of Kauai tonight and Monday, strong easterly winds will slowly diminish, and the threat of flooding will decrease. Trade wind flow will prevail Tuesday through Thursday, after which time winds will veer to east-southeast. && .DISCUSSION... Radar and satellite show widespread showers, some quite heavy, across most islands. The heaviest showers this afternoon have been over eastern Maui, eastern Oahu, northern Big Island, and most of Kauai County. Total rainfall has been extreme, with over 35 inches on Big Island, 10 to 15 inches on Maui, 5 to 10 inches on Molokai, Lanai, and Oahu, and 10 to 15 inches on Kauai. Wind damage (roofs off, trees down, power lines down, etc) has been widespread, but speeds are decreasing this afternoon and should decrease more through the evening. Although overall rainfall areal coverage is trending down, significant heavy rain continues in strong convective showers and even a few thunderstorms. Tropical Storm Lala continues to move away to the west, well southwest of Kauai. Tropical storm warnings remain for Kauai County, but have been cancelled for all other islands. A Flash Flood Watch remains for all islands except Big Island. Please stay up to date on the latest forecasts, as this is still an active severe weather event, and we are not done with it yet. In anticipation of critical new updates with each of the advisory packages issued by the National Hurricane Center (NHC), the NWS Honolulu will continue delaying the issuance of our typical forecast package products (AFD, SFT, PFM, ZFP, SPF, CWF, etc.) until after the release of NHC`s suite of products, to incorporate the latest and most up-to-date information on Tropical Storm Lala. As Lala departs to the west, winds will ease to moderate to locally breezy trades. Windward areas may remain wet with some risk for flooding due to a band of moisture trailing Lala. Inversion depth and therefore PW will remain a little higher than normal through the upcoming week, leading to relatively wet trades. These trades will veer to east-southeasterly Thursday night, and remain that way through next weekend. This will slightly shift the "windward" areas late in the week. && .AVIATION... Tropical Storm Lala continues moving W and was well southwest of Kauai. Continued improving conditions especially in terms of shra coverage and intensity is anticipated, although isolated heavier shower and thunderstorm risk will continue through 06-10Z. AIRMET SIERRA is in effect for IFR for Kauai through Maui. AIRMET TANGO is in effect for mod turb lee of terrain. TANGO is effect for SFC winds greater than 30 kts for Kauai. Generally improving conditions for all three AIRMETS is anticipated in the next 6-12 hours. && .MARINE... At 5 PM HST this evening, Tropical Storm Lala was moving west at 14 kts with its low level center located approximately 150 nm west-southwest of Lihue. A Tropical Storm Warning is in effect for the Hawaiian coastal waters around Kauai and a Small Craft Advisory is in effect for the coastal waters around Maui County and Oahu. Marine conditions are expected to gradually improve tonight through tomorrow. Large east-facing shore surf produced by Tropical Storm Lala has progressed westward across the state and is currently impacting Kauai and Niihau, where a High Surf Advisory remains in effect through midnight tonight. Surf will gradually fall below advisory levels overnight as Lala progresses further west of the state. North-facing surf will remain rough into this evening across the western end of the state as a result of this short period, Lala wind wave-driven chop in tandem with an east swell wrap. South-facing shore surf will stay below advisory thresholds but remain elevated from a combination of lingering medium period south swell and Lala short period east swell through this evening. Longer period south swell energy generated from gales just south and east of New Zealand will begin arriving late this week. && .FIRE WEATHER... Increasing humidity and rainfall from Lala will remove fire weather concerns in the short term. Moderate relatively moist trade winds will prevail Monday through at least Thursday. There is no temperature inversion tonight. && .HFO WATCHES/WARNINGS/ADVISORIES... Flood Watch through late tonight for Central Oahu-East Honolulu- Ewa Plain-Haleakala Summit-Honolulu Metro-Kahoolawe-Kauai East- Kauai Mountains-Kauai North-Kauai South-Kauai Southwest-Kipahulu- Koolau Leeward-Koolau Windward-Lanai Leeward-Lanai Mauka-Lanai South-Lanai Windward-Maui Central Valley North-Maui Central Valley South-Maui Leeward West-Maui Windward West-Molokai Leeward South-Molokai North-Molokai Southeast-Molokai West- Molokai Windward-Niihau-Oahu North Shore-Olomana-South Haleakala- South Maui/Upcountry-Waianae Coast-Waianae Mountains-Windward Haleakala. High Surf Advisory until midnight HST tonight for Kauai East- Kauai South-Niihau. Tropical Storm Warning for Kauai East-Kauai Mountains-Kauai North-Kauai South-Kauai Southwest-Niihau. High Wind Warning until midnight HST tonight for Haleakala Summit. Tropical Storm Warning for Kauai Channel-Kauai Leeward Waters- Kauai Northwest Waters-Kauai Windward Waters. Small Craft Advisory until midnight HST tonight for Alenuihaha Channel-Kaiwi Channel-Maalaea Bay-Maui County Leeward Waters- Maui County Windward Waters-Oahu Leeward Waters-Oahu Windward Waters-Pailolo Channel. && $$ DISCUSSION/FIRE WEATHER...Parker AVIATION...Munroe MARINE...Farris