Weather officials Wednesday released the wet-season rainfall outlook, with little relief in sight from Hawaii’s drought.
Due to El Nino conditions, Hawaii’s current drought is expected to continue well into next year, and possibly even into the 2024 dry season, according to the National Oceanic and Atmospheric Administration forecast.
“We’re seeing a really strong signal in our climate models that we’re going to be in a significant drought,” said NOAA hydrologist Kevin Kodama. “We’re already seeing significant or widespread drought that is expected to increase even moreso, especially by the end of February.”
By then, he said, Hawaii is expected to experience widespread moderate drought, with some portions of the state experiencing severe to exceptional drought.
This in turn means that dry vegetation will continue to provide potential fuel for out-of-season brush fires.
Hawaii’s dry season lasts from May to September, while the wet season lasts from October to April.
“Normally the wet season is when the vegetation will regrow and green up again, and so your fire risk lowers,” said Kodama. “In this case we’re not expecting to see substantial improvement in the fuels, and the fuels will still be dry.”
For instance, Diamond Head and Punchbowl usually green up during the wet season.
“I wouldn’t be surprised if Diamond Head stays brown the whole time,” he said. “That’s just part of what you would expect during an El Nino drought.”
This not only increases fire risk, but affects agriculture, creating hardship for those with nonirrigated crops and pastures, and residents relying on rainfall catchment systems.
Hawaii’s dry season
During this dry season, most locations had near- to below-average rainfall, according to Kodama.
This year’s dry season began a little later than usual, but this quickly changed by June, when drought developed then spread and intensified through the rest of the dry season, with severe drought, designated as D2 on the U.S. Drought Monitor map, seen in all four major counties.
Extreme drought developed in leeward Maui and some parts of Hawaii island, resulting in conditions that helped fuel the devastating Aug. 8 wildfires.
As of Wednesday, the drought monitor map showed more than 16% of Hawaii was in the severe to extreme drought range, designated as D2 to D3. There was little relief for leeward Maui, where extreme drought conditions, D3, continued.
By the end of February, this is expected to increase to more than 40% of the state.
NOAA said it was the eighth-driest dry season in the past 30 years. The driest dry season was in 2010, while the wettest dry season was in 2015, in the past 30 years.
“Right now we’re in El Nino conditions,” said Kodama. “The El Nino event developed during spring, intensified during summer months and is ongoing and still becoming stronger.”
NOAA’s Climate Prediction Center says there is a 3 in 10 chance of a “historically strong” El Nino event this season compared with other strong events that took place in 1997-1998 and in 2015-2016. El Nino is anticipated to continue into spring.
That means below-average rainfall through the entire wet season and widespread drought continuing into the 2024 dry season, which begins in May.
“Normally, with a strong El Nino, drought takes hold in mid-December at some point and then extends into the February and March timeframe,” said Kodama, “but this time around we’re already in it.”
It also means big surf for Hawaii’s north shores, especially in January and February.
Generally, El Nino events have not lead to red-flag warning conditions during wet seasons in the past decade, Kodama said.
The three elements leading to a red-flag warning include warm temperatures, very low humidity and strong wind. The easterly tradewinds usually weaken during El Nino, but the exception was in 2010.
In March and April of 2010, there were several red-flag warnings due to trades, he said, and there could be potential for that this spring as well.
Although drought is expected, Kodama reminded the public that there might still be isolated heavy rain events, leading to potential flash floods.
He reminded the public not to drive on roads with fast-flowing water or walk across flooded streams. Those who live in a flood-prone areas should still identify alternative routes ahead of time and have an evacuation plan in place.
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Wet-season outlook for Hawaii
>> An El Nino season with below-average rainfall
>> Widespread moderate drought (D1) with embedded areas of severe to exceptional drought (D2 to D4) expected to continue into 2024 dry season
>> Higher chance of large north shore surf events, especially in January and February
Source: NOAA