Kauai's Dry Trade Winds Give Way to Norbert's Rain as Flood Watch Looms
Weather on Hawaii's island of Kauai is shifting from a dry trade-wind pattern to heavy rain and possible flooding as the remnants of former Tropical Storm Norbert move through on Wednesday, September 16, with a flood watch possibly issued as early as Thursday.
Weather patterns on the Hawaiian island of Kauai are changing rapidly this week, shifting from relatively dry trade winds to heightened rain chances and a possible flood threat, according to National Weather Service forecasts published by local outlet Kauai Now.
From dry to wet
As of September 11, forecasters described a return to a typical, relatively dry easterly trade-wind pattern following the departure of moisture from former Tropical Storm Lowell, with only a chance that a new disturbance could bring rain by midweek. By September 15, that disturbance had been identified as the remnants of Tropical Storm Norbert, expected to become post-tropical on Tuesday and to bring heavy rain, isolated thunderstorms and high humidity from Wednesday night through Friday morning, though without significant wind or surf impacts. Forecasters already flagged the possibility of a flood watch for Thursday.
The September 16 forecast confirms this trend: trade winds were set to strengthen to breezy levels through Wednesday, while moisture continued spreading across the islands from east to west, raising shower chances mainly over windward and mountain areas. Chances of heavy rain, isolated thunderstorms and flooding were expected to increase from Thursday into Friday as an upper-level disturbance moved overhead. A flood watch could be issued as early as Wednesday.
Wednesday, September 16 forecast
West Kauai: mostly clear overnight with isolated showers, lows of 66–75°F; sunny by day with isolated showers, highs of 80–93°F, 20% chance of rain. South Kauai: 40% daytime rain chance, rising to 70% overnight, with locally heavy rainfall possible after midnight. The Kauai mountains face the highest risk, with overnight rain chances reaching 90%. North and East Kauai: daytime rain chances around 50–60%, climbing to 90% overnight, also with locally heavy rain possible after midnight. Trade winds islandwide were forecast to reach moderate to breezy strength, gusting up to 20 mph.
What comes next
Drier conditions are expected to return over the weekend as trade winds persist. However, according to the September 16 forecast alone — a detail not mentioned in the earlier reports — another round of enhanced moisture could arrive early next week, on Monday or Tuesday, from the remnants of former Tropical Depression 15-E, potentially triggering a new wave of trade-wind showers.
