For many, it was close. Very close.
“I’d say they’re breathing a sigh of relief,” said Chevy Chevalier, a meteorologist at the National Weather Service and the Central Pacific Hurricane Center. “Fifty miles is nothing when you’re talking about the entire Pacific.”
Hurricane warnings were dropped for the entire archipelago by early Monday morning. The storm’s center slipped a mere 39 miles north of Kauai shortly before 1 a.m. local time on Monday. Hurricane-force winds extended outward only 25 miles from the center, keeping the intense core of wind just offshore.
At 2 a.m. local time, the storm’s peak winds were 90 mph as it zipped off to the west-northwest at 16 mph.
A very close call
Conditions on Kauai would have been significantly more severe if the eyewall had managed to brush its northern shore, which it missed by only 27 miles. There is a dramatic increase in winds once one enters the eyewall. Thunderstorms within the eyewall were up to 45,000 feet tall.
Douglas barely grazed other islands along the chain, including Molokai and Oahu. Farther south, Maui and the Big Island were subjected to largely peripheral effects, including from Douglas’s outer rain bands, as well as rough surf and an increased threat of rip currents.
Otherwise, Douglas’s impacts were largely limited to lingering rain and gusty winds on Kauai that will persist through the early to midmorning hours Monday.
“[No significant impacts] that we know of,” said Chevalier. “It did not make landfall. There was some rain. Most of the rain, to be honest, now is falling right now over Kauai. … The biggest impact we see over this are the rains right now.”
At 1 a.m. local time, or 7 a.m. Eastern time on Monday, Doppler radar revealed a few light showers over Kauai. An isolated downpour associated with a ragged feeder band was clipping northeastern Oahu.
Radar data did depict some acute organization of one north- to south-oriented feeder band, which could produce a brief burst of rainfall in southern Kauai. An isolated waterspout offshore is possible as well.
Localized rainfall totals may top three inches in northern Kauai, with amounts largely influenced by the island’s mountainous terrain. A flood advisory was issued after gauges on the Hanalei and Wainiha rivers indicated elevated water levels.
“Not much has fallen over the rest of the islands,” said Chevalier. “This rain [in Kauai] hasn’t been falling that long.”
Honolulu Mayor Kirk Caldwell (D) tweeted a graphic when the hurricane warning was dropped for Oahu that jovially instructed the island’s residents to “untape [their] slippahs.”
In Honolulu, the Hawaii Convention Center opened its doors to between 200 and 300 residents during the storm’s close encounter, the majority of whom were homeless.
“Great love being shown by our residents coming down here to volunteer for those who would otherwise have no love whatsoever,” said Caldwell in a video posted to Twitter.
Honolulu was largely unaffected by the storm, with a wind gust to 29 mph recorded around 3 p.m. Sunday and 0.03 inches of rain.
Conditions have already returned to “normal” Hawaii weather for the Big Island, Maui and Molokai, while Oahu and Kauai will see dwindling impacts that largely vanish by sunrise. Improving weather is forecast throughout the day Monday, with breezy trade winds and typical chances of isolated overnight and morning showers.
Douglas’s climb to power
Douglas first organized from a tropical depression more than 2,000 miles east of Hawaii, earning its name as a tropical storm on July 21 as it drifted west-southwest. On July 23, Douglas become a hurricane — the Pacific’s first of the 2020 season — and rapid intensification ensued. In just 18 hours, Douglas grew into a Category 4 cyclone with 130 mph winds, its intensity clear via its satellite aberrations as the storm ominously whirred west.
Since then, Douglas has gradually lost strength, outrunning the warm waters of the deep tropics that had sustained its impressive reign.
Forecasters were sounding the alarm for potential impacts in Hawaii five or six days ago, when the system was still 1,500 miles distant.
“It was a pretty good forecast, even a week ago,” said Chevalier. His forecast office also staffs the Central Pacific Hurricane Center, which tracks hurricanes that move west of 140 degrees west longitude. “I guess you could say there was a shift towards the end there. Instead of crossing over Oahu toward the leeward side of the island, it just sort of skirted up the windward side[s] of Oahu and Kauai.”
It’s not unusual to have erratic turns, jogs or “trochoidal wobbles” complicate a hurricane forecast last minute. In August 2019, Dorian — then a budding tropical storm — was expected to slip through the Mona Passage between Hispaniola and Puerto Rico. At the last minute, however, the cyclone shifted course, passing east of Puerto Rico and bringing hurricane-force winds to Vieques.
That change in track allowed Dorian to continue gaining strength without being disrupted by the terrain of Hispaniola, which proved to be a factor that allowed the storm’s rise to extreme and virtually unmatched ferocity.
Hawaii’s hurricane history
Despite the tropical environment, Hawaii does not see hurricanes as commonly as one might think. In fact, only two have made landfall in the Aloha State since the National Hurricane Center’s database of reliable records began. The islands are more frequently visited and sideswiped by lesser systems or the remnants of tropical cyclones.
“This is the first threat to Hawaii in a while in terms of if it would have made landfall,” said Chevalier. “If it would have made landfall, it would have been the first tropical cyclone to make landfall ever during July. There have only been 10 [landfalling tropical cyclones] since 1940.”
On Sept. 11, 1992, Category 4 Hurricane Iniki plowed through Kauai with 140 mph winds, damaging or destroying more than 14,000 homes. It was the strongest storm to affect Hawaii in modern times.
Even without direct hits, tropical storms and hurricanes can prove serious when it comes to the prolific rainfall they often release. Hurricane Lane collapsed upon approach to Hawaii in August 2018, dumping upward of 52 inches on Mountain View on the Big Island, a community 15 miles south-southwest of Hilo.
As sea-surface temperatures continue to warm largely because of human-caused climate change, it’s probable that more tropical cyclones will wander closer to the Hawaiian islands in the years ahead.