Strengthening low pressure roughly 750 miles north of Kauai will produce increased south winds through Thursday and will draw deep tropical moisture over at least the western half of the island chain. The threat of heavy flooding rainfall and thunderstorms will be greatest tonight and Thursday over Kauai and Oahu, where a Flood Watch is in effect. Chances for heavy rain will diminish on Friday as the low weakens several hundred miles northwest of Kauai. The low will slowly fill Saturday and Sunday, though a few heavy showers may linger through the weekend under southeast to east winds.
Light southerly winds will increase in speed and become more southerly through Thursday due to a surface trough approaching from the west. Increasing showers and isolated thunderstorms are forecast tonight and Thursday as an area of enhanced moisture moves up from the south and instability increases. MVFR conditions likely and IFR conditions possible within heavier showers and thunderstorms. VFR prevails elsewhere.
AIRMET Sierra is in effect for tempo mountain obscuration across all of Kauai and south through west facing portions of Oahu, Molokai and Lanai. This AIRMET will likely be needed for portions of the island chain through Thursday.
Issued at 323 PM HST Wed Oct 7 2026 Gentle to moderate south to southeast winds will continue over the next couple of days as a low pressure system develops north of Hawaii. Enhanced showers with the potential for a few thunderstorms are forecast for the western half of the state through Thursday. A surface trough will linger near the area through the weekend and early next week keeping potential for variable winds and unsettled weather.
South swell will maintain into next week with pulses of long period reinforcement arriving Thursday and Saturday. Surf will stay below advisory levels along south facing shores.
Small to moderate surf along north and west facing shores will continue through the rest of the week as swell energy is reinforced by the slowly moving surface low northwest of the Hawaiian Islands. A larger swell will arrive around Tuesday, bringing north and west shore surf to just below advisory thresholds. Surf along east facing shores will remain small as local winds remain fairly weak.
Flood Watch through Thursday afternoon Niihau, Kauai, and Oahu. Wind Advisory until 4 PM HST Thursday for Big Island Summits.
