KAILUA-KONA — Above-average rainfall forecast this winter into spring is expected to provide relief to parched areas of Hawaii Island.
While many locales have recorded plentiful rainfall in recent months and showing no sign of drought conditions, the top third and southernmost tip of the island have been left high and dry. That’s despite the state coming off the seventh-wettest dry season in the past 30 years.
“Some localized areas ended up pretty bad,” said Kevin Kodama, senior hydrologist for the National Weather Service in Honolulu.
The dry season ended Sept. 30.
All of North Hawaii, from Honomu straight across and into parts of coastal North Kona, is listed as abnormally dry, according to this week’s U.S. Drought Monitor issued Thursday. Swaths of severe and moderate drought have hit Hamakua areas and extreme drought has taken hold over a sizable chunk of North Kohala from Mahukona to Hawi.
At South Point, also known as Ka Lae, is a very localized patch of drought with a spot of extreme drought, one step below the worst classification, exceptional drought. A fire recently burned there, scorching 121 acres.
“They’ve been very dry,” said Kodama. “Some ranchers have indicated pasture (impact) and it’s showing up in our satellite vegetational data with this spot of very poor conditions.”
But, relief should be ahead, thanks to ENSO-neutral conditions forecast by NOAA’s Climate Prediction Center for this upcoming wet season, which continues through spring 2020, and above-average sea surface temperatures.
ENSO-neutral conditions, which occur when neither El Nino nor La Nina is present, tend to produce wetter-than-average wet seasons for the state. In the past three decades, Kodama said, eight of the top 10 rainiest wet seasons have occurred amid ENSO-neutral conditions.
“Existing drought areas that we have around the state, by the end of April, I think, they’re all going to be gone,” Kodama said Thursday after the release of the service’s wet season outlook. Hawaii’s wet season runs October to April, though the Kona coffee region runs opposite.
While Hilo is known as the rainiest city in the U.S., parts of West Hawaii — in particular the Kona coffee region — have outpaced Hilo for rainfall the first nine months of 2019. A wetter-than-average dry season — wet season for Kona — had been forecast for the entire state.
“It’s wetter than we’ve seen in a while,” Kodama said. “Everywhere was above-average on the Kona side.”
Waiaha’s total of 75.43 inches through September is almost twice its average of 38.53 inches for the first nine months of the year. And Kealakekua logged 73.65 inches of rain through September, 160% of its norm of 45.92 inches for the period.
Hilo, in comparison, had a hot and relatively dry summer, with year-to-date rainfall at 65.55 inches, 73% of the normal 90 inches.
A lack of volcanic activity and warm surface temperatures may have contributed to the increase in Kona rainfall.
“The vog would tend to hinder rainfall production so the fact that it’s not going you have much less activity and combined with the warmer-than-average sea surface temperatures — I think those two factors have helped to really make the Kona side wet this summer,” Kodama said.
Kodama said the region will likely continue to be wetter than normal, even though it’s entering its dry season because of the forecast above-average wet season forecast for the rest of the island and state.
“Kona’s going to see their share of the rain. It’s going to continue to be wet, but maybe not as regular,” said Kodama, noting rain has become a daily occurrence for many Kona areas. “It’ll be more spaced out, but with higher potential for heavy rain events and thunderstorms between.”
Hawaii Tribune-Herald reporter John Burnett contributed to this report.