Rainy season arrives, but drought conditions persist in some areas

It appears the wetter-than-average rainy season for Hawaii Island has arrived — at least in some areas.

According to the monthly precipitation summary from the National Weather Service in Honolulu, rain gauges on both sides of the island recorded near-average to above-average readings in October.

Hilo International Airport reported robust rainfall last month, 13.8 inches. That’s 141% of its October average of 9.77 inches. It also brought the yearly rainfall total for the first 10 months to 79.35 inches, 80% of the norm of 99.65 inches.

Above-average October totals also were tallied at Mountain View with 14.4 inches, more than an inch above normal; Pahoa with 13.87 inches, more than 2 inches above average; and Hakalau, with 5.83 inches, 7% above its usual 4.83 inches.

Kevin Kodama, the National Weather Service’s senior hydrologist in Honolulu, said even with below-average rainfall for the first nine months of the year, there hasn’t been any drought indicators for most of East Hawaii.

“I guess it’s no news is good news,” said Kodama.

The Kona and Ka‘u coffee belts also continued to experience above-average rainfall last month, although Kona experiences its wet season in the summer.

Kealakekua totaled 6.57 inches, 152% of its usual 4.33 inches for the month. Waiaha was even wetter, with 7.4 inches, more than twice its October norm of 3.42 inches. Kainaliu’s monthly total of 5.58 inches is about one-third more rainfall than the usual October tally. Honaunau was actually drier than normal last month with 4.21 inches of rain, 82% of average, but its 2019 to-date total of 66 inches is well above its average of 50.22 inches for the first 10 months.

Waiaha also reported the wettest day of the month for the Big Island, 2.73 inches on Oct. 11, edging out Mountain View’s 2.72 inches the same day.

“They’re past their peak in terms of the summer rainfall, but they’re still getting above-average rain,” Kodama said.

In Ka‘u, Kapapala reported 7.84 inches of rain, almost 160% of its usual 4.95 inches. Pahala received 6.07 inches, almost an inch more than normal. Kahuku Ranch recorded 4.63 inches as opposed to an October norm of slightly less than 3 inches. And South Point’s 3.32 inches is almost an inch above its normal October rainfall, although part of the area is still in drought.

“The South Point drought area is really localized, and it’s makai from our rain gauge,” Kodama said. “We’ve had to depend on farmer reports and satellite vegetation health data. It’s showing some improvement, but I still am waiting for the impact reports from the ranchers and farmers. As far as I know, it’s not in good shape yet.”

There also were some below-average rainfall totals, concentrated in the Hamakua and Kohala regions, which are both experiencing drought conditions.

Honokaa reported just less than 2 inches of rain for October, about a third of its norm of 5.48 inches. Laupahoehoe also had a dry month, with 2.83 inches compared to its October norm of 11.35 inches.

Kohala Ranch and Kahua Ranch both received less than an inch of rain in October. That’s about average at Kohala Ranch, but Kahua Ranch’s 0.88 inches is only a quarter of its October average of 3.54 inches.

“Mahukona’s really dry. Waimea’s pretty dry, too,” Kodama said. “From the reports and the pictures I’ve been getting from the ag folks, there’s no usable pasture up in Mahukona. It’s not quite as bad along the Hamakua Coast, but for what you would normally expect over there, it’s pretty dry and the pastures are degraded.”

Kodama said the dry conditions in Hamakua and Kohala have persisted, “likely due to the shift in low-level winds to an east to east-southeast direction instead of the more usual east-northeast direction.”

“That’s been going on since summer, and it’s having a big impact now,” he said.

Email John Burnett at jburnett@hawaiitribune-herald.com.
Source: Hawaii Tribune Herald