After a particularly rainy summer, many parts of the island already received more rain this year than throughout the entirety of 2017.
Official data from the National Oceanic and Atmospheric Administration reveals that August of this year was exceptionally rainy thanks largely to the arrival of Hurricane Lane. By the end of that month alone, some places on the Big Island received nearly 70 inches of rain.
“It was a wet month even without Lane,” said National Weather Service hydrologist Kevin Kodama. “But that just put everything way over the top.”
Kodama said the enormous rainfall totals of Hurricane Lane shattered nearly all long-term August rainfall records on the Big Island.
Nearly all rain gauges on the east side of the island recorded more than double their average rainfall in August, with most recording triple, quadruple or quintuple their averages. Hilo airport, which typically sees less than 10 inches in August, saw 48 inches, nearly 500 percent the monthly average. So far this year, the airport has received 129 inches of rain.
Pahoa received 47 inches in August, while Papaikou received 44 inches, Mountain View received 69 inches and Laupahoehoe 49 inches. Waikoloa, on the other hand, received 2.56 inches, which still accounted for 676 percent of its average August total.
Even on the west side of the island, typically much drier than the east side, most gauges saw several times more rain than average. One rain gauge in Kapapala received 25 inches, 820 percent of the August average.
On the other hand, Ellison Onizuka Kona International Airport was one of the few gauges on the island to receive less rain than average. The airport recorded just 1.12 inches in August, or 81 percent of its average. Kona’s total rainfall so far this year is 8.6 inches, about 30 percent less than its average of 10.72 inches.
Between January and August of this year, the Saddle Quarry rain gauge recorded 287 inches of rainfall, more than 300 percent of its average total rainfall within the same period. Although total Saddle Quarry rainfall data from 2017 and 2016 are not available, the average yearly rainfall for the area is approximately 140 inches.
As Saddle Quarry approached the 300-inch mark, several other windward regions received nearly 200 inches by the end of August. Mountain View, which received 143 inches of rain in 2017, has seen 190 inches of rainfall this year to date. Piihonua received 189 inches, 50 inches more than its total rainfall last year.
Although Kodama speculated that the heavy rainfall would not have a long-term effect on the island’s water table, flooding caused by Lane is estimated to have caused about $20 million in damage to the county’s infrastructure.
Kodama said the National Weather Service is currently tracking a low-pressure system to the southwest of the state that has the potential to develop into a tropical storm in the next five days. Other than that, the only other storm in the East Pacific is Tropical Storm Rosa, which at press time was predicted to circle back toward the Baja California Peninsula.
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.