Hurricane Lowell’s passage west of Kauaʻi and Niʻihau resulted in damaging winds, heavy rainfall—more than 23 inches recorded on Mount Waiʻaleʻale—and dangerous surf.
To understand the storm’s full impact, a University of Hawaiʻi team reconstructed Hurricane Lowell hour by hour across Kauaʻi and the state using observations from the Hawaiʻi Mesonet, a statewide network of weather stations, alongside experimental high-resolution mapping tools.
The most notable weather signal during the storm was the wind.
The highest measured hourly average wind speed reached 56 mph late on Sept. 7 at the Līhuʻe Airport. However, since Kauaʻi’s weather stations are primarily at lower elevations, experimental high-resolution modeling was utilized to estimate conditions across remote terrain.
The models suggest that winds over exposed high-elevation ridges were much stronger, locally exceeding 100 mph as the island’s steep topography accelerated airflow over ridges and through valleys.
High-elevation and north shore sensors show Mount Waiʻaleʻale recorded more than 23 inches of rain on Sept. 7, accumulating nearly 36 inches over the full three-day storm period.
Meanwhile, on Kauaʻi’s north shore, rising river waters led to the closure of Hanalei Bridge, with Hawaiʻi Mesonet stations at Waipā and Lower Limahuli recording more than 14 and 17 inches of rainfall, respectively, during the storm.
Nearly all of Kauaʻi received more than 2 inches of rain, with many areas exceeding 5 inches.
The report also references information from the Pacific Islands Ocean Observing System on the significant coastal hazards brought by the storm. Large surf and storm surge impacted south- and west-facing shores of Kauaʻi as the hurricane tracked to the west.
The University of Hawaiʻi team launched a dedicated Hurricane Lowell website to make these complex meteorological observations accessible to the public and emergency responders. Users can explore interactive wind and rainfall maps, station observations and satellite storm replays.
