More than a month into Hawaii’s annual dry season, drought conditions persist in much of West Hawaii, and large portions of East Hawaii are starting to tip into a similar state.
According to the U.S. Drought Monitor’s most recent report, published Thursday, a swath of the windward side from roughly Hakalau to Paauilo was classified as being “abnormally dry.” The Paauilo-Honokaa stretch is under moderate drought.
“In May it was pretty good, and we were in pretty good shape on the windward side,” said National Weather Service hydrologist Kevin Kodama. “But now it’s dropped off a fair amount and the Wailuku River is (getting) low.”
The drought monitor website notes “recent field observations and rancher input … indicated that parts of the Big Island are worse than expected.”
May rainfall totals on Hawaii Island were in the near- to below-average range, with yearly totals largely below average throughout the island. The rain gauge at Kawainui Stream has the highest year-to-date total rainfall — 55.83 inches, or 82 percent of average. Kawainui recorded 6.36 inches in May, or 50 percent of average.
The drought monitor report shows the area around Kailua-Kona, most of South Hilo and Puna as being drought-free. All other areas, however, have been impacted to some degree by a lack of rainfall.
Mark Thorne, state range and livestock extension specialist with the University of Hawaii at Manoa’s College of Tropical Agriculture and Human Resources, said the east-side drought was “at a developing stage” right now.
“We have to be very cognizant of the potential for drought, and ranchers should be watching for that,” he said.
“That happens periodically on that side, the short dry periods. We’ll have to see if these weather patterns continue to persist on that side. We had a good rain last night in Paauilo, so that’s good to see.”
The leeward side, however, has been behind on moisture for about six months and is impacting farms in the area.
“It’s been intermittent here and there, but particularly severe since December,” Thorne said. “Production is falling a little bit.”
“Areas like Ka‘u and South Kohala, they’re getting pretty dry, and the likelihood of any substantial relief until the fall is pretty low,” Kodama said. “It’s just not favorable for getting any sort of rain.”
Thorne said the leeward-side drought in South Kohala was likely worse than the U.S. Drought Monitor indicated because the Waimea weather stations are located on the wetter side of town.
Ranchers have complained about this because the drought monitor classifications determine whether farms are eligible for federal drought relief funding.
Drought in the area isn’t uncommon: Thorne said that between 2006 and 2014 “practically the entire island and most of the state was in a severe drought.” Last year was a more normal pattern, he said.
The shift to the dry season, which spans May through September, comes on the heels of a kona low weather pattern, which brought rain and flooding on the island at the start of May. Kona lows usually occur in the winter.
The trade winds have been “erratic and spotty,” Kodama said. “It’s hard to pin down one reason … the whole North Pacific pattern is a little off right now. It’s not appearing very summerlike.”
“It should stabilize,” he said. “You can’t stop the march of the seasons.”
Email Ivy Ashe at iashe@hawaiitribune-herald.com.
