Maui rainfall totals below 50% of average for November 2024

November rainfall totals at most of the gages across Maui County were below 50% of average, according to the monthly Hawaiʻi Rainfall Summary report filed by Kevin R. Kodama, Senior Service Hydrologist at the NOAA/NWS Honolulu Forecast Office.

All of the sites within Maui’s central valley had rain totals below 10% of average, according to the report. The USGS’ rain gage at West Wailuaiki Stream had the highest monthly total of 15.64 inches (79% of average), and the highest daily total of 2.51 inches on Nov. 13. Kahului Airport and Hāna Airport had their lowest November totals since 2011 and 2012, respectively.

Despite the recent dry conditions, rainfall totals for 2024 through the end of November were still near to above average at most of the gages across Maui County. The rain gage at West Wailuaiki Stream had the highest year-to-date total of 198.49 inches (95% of average), Kodama reports.

Statewide, unstable conditions aloft that started in late October continued into early November. These conditions helped produce the main rain events for the month. On Nov. 4, a low level trough with deep tropical moisture moved over the Big Island from the east. The deep tropical moisture combined with unstable conditions aloft and terrain forcing to produce a prolonged period of heavy rainfall with more than 5 inches of rain covering the eastern third of the island, with bias-adjusted radar estimates indicating more than 15 inches of rain over the slopes northwest of Hilo.

On Nov. 6, a weak cold front reached Kauaʻi, then moved eastward across Oʻahu before dissipating over Maui County on Nov. 7. While rainfall associated with the front did not produce flooding problems, it did mark the first cold front passage over the main Hawaiian Islands for the October through April wet season, Kodama said. The first frontal passage usually occurs around the third week of October so this was a bit late, according to the report.

After the front dissipated, trade winds filled in on Nov. 8 and continued uninterrupted through Nov. 22. During this time, the trades reached gale force strength on Nov. 14-16 in the Alenuihāhā Channel. After Nov. 22, a shift in the North Pacific weather pattern moved the low level subtropical ridge close to, or over the main Hawaiian Islands, which resulted in light surface winds for the remainder of the month.