The remnants of Tropical Storm Fausto drenched windward Hawaii Island earlier this week and moisture just behind it has helped bail leeward areas out of six years of drought.
Laupahoehoe and Hilo were slammed with about 4.5 inches in a 24-hour period Sunday and South Point received close to 3 inches.
“You run a system like that into a big volcano and it’s just going to dump,” said National Weather Service hydrologist Kevin Kodama.
Little moisture was measured in West Hawaii until Monday, when Kona International Airport and Honaunau gauges each registered around a third of an inch. Unstable conditions and rainfall continued Tuesday after the Fausto system passed, with Kealakekua measuring close to three quarters of an inch.
Before the system ever drew nigh the island, Kona coffee growers were already seeing the wetter conditions favorable to their crops.
Kealakekua had the wettest May on record. The region received 9.7 inches of rain, the most in the 23 years the gauge has been in place, Kodama said. Typical May rainfall for that area is 5.3 inches.
The Honaunau gauge registered its highest reading for June in 17 years — 8.6 inches, which is 137 percent of average.
May was wet in other areas of West Hawaii as well. Holualoa got 17 inches of rainfall, said coffee and avocado farmer Bruce Corker, whose farm is situated close to the 1,300-foot level.
“The coffee loves it,” Corker said. “It increases the crop, and the moisture tends to promote the growth of the fungus that kills the coffee borer beetle.”
Rainfall increases from the month of February onward helped moisten parched regions of the leeward Big Island and other portions of the state, various areas of which were under severe drought designation since 2008.
Kaloko-Honokohau National Historic Park, with 15.3 inches, has half again the normal levels for the year. And Kohala Ranch is 240 percent of normal with a whopping 16 inches on a dry leeward slope that doesn’t normally feel more than 6.6 inches a year.
“When I go to drought committee meetings on the Big Island, folks tell me, it’s been wet,” Kodama said. “In April, we dropped out of (drought) criteria, and I didn’t have to do any drought statements, which was different.”
“It’ll be back,” Kodama added. “You can count on it.”
Although Hilo received its highest rainfall for the month of June since 2005, with 6.6 inches, the measurement was still below average.
“That just shows how dry it’s been in Hilo,” Kodama said. “Our summer tradewind rainfall has been on a downward trend.”
Another area of tropical moisture is forecast to arrive Saturday, Kodama said. Situated about 1,000 miles southeast of the Big Island, the system isn’t expected to form a tropical cyclone, but it’s likely to bring rain through Monday.
Email Bret Yager at email@example.com.