LIHUE — On the heels of the second-wettest dry season in the last 30 years, the wet season outlook for Hawaii says there’s more moisture on the horizon.
“Probabilities favor above average rainfall early in the wet season,” said National Oceanic and Atmospheric Administration’s Kevin Kodama in a Friday announcement about the outlook. “Probabilities favor below average rainfall starting December and persisting into the spring.”
That’s due to the likely transition into a weak El Nino state, or warm phase, which allows for heavy rains to affect the state.
Currently, we’re in an ENSO-neutral state, which means neither El Nino nor La Nina is present. According to NOAA’s Climate Prediction Center, that’s when ocean temperatures, tropical rain patterns and atmospheric winds over the Pacific are near long-term averages.
In June, CPC issued an “El Nino watch,” and the center now says there is a 70 to 75 percent chance of an El Nino developing during the next couple of months.
Once it develops, experts predict the El Nino will persist until the spring when conditions may transition back to an ENSO-neutral state.
Even though there’s a probability of heavy rain events throughout the winter and into the spring, NOAA experts are predicting some drought development on leeward slopes by the end of February.
“Below average rainfall is expected statewide during the winter, but not as dry as 2009-2010,” Kodama said.
That year, NOAA records show exceptional drought throughout much of the year, with abnormal and exceptional drought conditions in February, June and September.
The summary of the May through September 2018 dry season in Hawaii is nearly as wet, with above average rainfall conditions at most locations throughout the state.
“(It was the) secondwettest dry season in the last 30 years,” Kodama said. “Record breaking wet conditions in August and September.”
The last month of the wet season brought torrential rains to much of the state, including Kauai, which experienced severe flooding from Friday, April 13 through Sunday, April 15. Rainfall totals on Kauai during the event were record-breaking.
“The highest 24-hour total from the real-time sites was 28.15 inches at Hanalei from 2 a.m. on April 14 to 2 a.m. on April 15,” NOAA officials catalogue in a report. “The data logger failed at the Hanalei site during the event so the total would have been higher.”
The report points out an observer from the Community Collaborative Rain, Hail, and Snow Network (CoCoRaHS) in lower Wainiha Valley reported 36.49 inches during the period from 7:45 a.m. on April 14 through 7 a.m. on April 15. A couple of days after the event, data from an automated rain gauge in Waipa about one mile west of Hanalei were retrieved and analyzed.
The results showed that this site recorded 49.69 inches during the 24-hour period ending at 12:45 p.m. on April 15. This total, if certified, breaks the current U.S. 24-hour record of 43 inches at Alvin, TX on July 25-26, 1979, and the State of Hawaii record of 38 inches at Kilauea (Kauai) on January 24-25, 1956. The National Climatic Extremes Committee is in the process of validating this claim.
There were some drought conditions that developed in the early summer on Maui and then on the leeward areas of Big Island and Oahu, and droughts in Maui and on Big Island reached severe levels. Drought disappeared in early October following vegetation recovery.
With more rain in the forecast for the wet season — which runs from October through April — Kodama touted reminders for preparedness: don’t drive or walk through fast-flowing water or flooded streams, prepare for increased travel times and other rainy-weather impacts, and to stay informed.
“Conditions can change rapidly,” Kodama said. “Sunny skies can turn cloudy with intense rainfall in less than an hour.”
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Jessica Else, environment reporter, can be reached at 245-0452 or at jelse@thegardenisland.com
As long as the El Nino disappears before hurricane season starts!
Interesting how SA and TGI headlines on the same article are complete opposite.