Thanks to an unusually wet dry season, rainfall totals throughout East Hawaii should be close to — or at — normal amounts by the end of the year.
Thanks to an unusually wet dry season, rainfall totals throughout East Hawaii should be close to — or at — normal amounts by the end of the year.
That’s according to a report released last week by the National Weather Service that showed many windward areas on the Big Island received at or above-average rainfall in September.
The rain gauge at Hilo International Airport recorded 10.74 inches in September, which is nearly an inch above normal and pushes the site’s year-to-date rainfall total to 88 percent of average.
Glenwood registered more than 20 inches for the month, which is 113 percent of its average and puts its year-to-date total at 69 percent. Mountain View recorded about 20 percent more rain than its monthly average, putting it at 89 percent for the year.
The Saddle Road Quarry recorded more than 26 inches of rain in September, which is 266 percent of normal and puts the site at 202.85 inches for 2016 — nearly two times the average for the year thus far and the third-highest rainfall total in the state.
The NWS attributes September’s heavy rain in part to “abundant moisture from the tropics” early in the month shortly after Tropical Storm Madeline passed by in late August, followed by Tropical Storm Lester. Many windward sites also recorded above-average rainfall in August. Early this year, much of the island was unusually dry as a result of El Nino-induced drought conditions.
“We had a tale of two seasons,” NWS forecaster Derek Wroe said. “We started off the year extremely dry in January and February … . Then, heading into the dry season for most places it started getting wet. So, we had sort of a reverse — a drier-than-normal wet season and a wetter-than-normal dry season.
“We’re ending the year in a normal condition, but that doesn’t tell the whole story.”
Many leeward sites saw below-normal rainfall in September. South Point recorded 1.41 inches for the month — 56 percent of average. Kealakekua recorded 2.73 inches, 39 percent of normal and its lowest September total since 2006.
Wroe said leeward areas tend to get more “pop up” rain and “afternoon showers,” which is “a little less certain.”
“They don’t see the steady rainfall totals that we see on the windward side,” he said.
Email Kirsten Johnson at kjohnson@hawaiitribune-herald.com.