“This total, if certified,” wrote the National Weather Service office in Honolulu, “will break the current U.S. 24-hour record.” The previous long-standing record came from Tropical Storm Claudette, which dropped 43 inches on Alvin, Tex., on July 25-26, 1979.
A figure as absurd as nearly 50 inches required a special committee to confirm its legitimacy.
The process, which began last April, wrapped up in December, when an official report was released. The National Climate Extremes Committee “determined the Waipā Garden observation to be valid,” it stated.
Aug. 22-26, 2018: State tropical rainfall record
Hurricane Lane was a juicy storm over the Hawaiian archipelago. It dropped 52.02 inches in Mountain View on the Big Island. That eclipses the previous Hawaii tropical rainfall record of 52 inches, set during Hurricane Hiki in 1950. Neighboring stations supported this observation — nearby Waiakea Uka picked up 49.48 inches, while a U.S. Geological Survey gauge at Saddle Quarry saw 48.52 inches.
A nearby private station measured 58.08 inches during the same time frame.
The episode propels Hurricane Lane — whose spiral rain bands lashed the Big Island during the cyclone’s deterioration — into the No. 2 spot for U.S. storm total rainfalls. The victor, Tropical Storm Harvey, set its record less than a year earlier — a trend that probably portends wetter times to come.
Honolulu has warmed 2.32 degrees since 1950. As per the Clausius-Clapeyron relationship, that corresponds to a 10 to 12 percent increase in the amount of water vapor the air can hold. That in turn boosts rainfall rates during intense storms, allowing the water to pile up faster. It’s yet another symptom of a warmer and wetter world.
Summer rainfall totals are trending upward. 2015 marked Honolulu’s wettest summer on record.
Hurricane season 2018: A trio of storms in Hawaii
Lane was one of three storms that hit Hawaii in the 2018 hurricane season. The August windstorm was preceded by Hector two weeks earlier, which clipped the Hawaiian Islands with gusty winds, dangerous surf and blinding squalls. And about two weeks after Lane, Olivia swung in, marking the first time on record three or more tropical cyclones directly affected the state in a single season.
Ordinarily, Hawaii’s position far enough north keeps it away from most storms. But that might not be the case in the future, because of climate change.
Bin Wang works for the University of Hawaii at Manoa. His team predicts a “substantial increase in the likelihood of tropical cyclone frequency [in Hawaii] … with a northwestward shifting of the tropical cyclone track.” In other words, Hawaii is likely to find itself in the crosshairs of more violent storms in the not-too-distant future. The scientists predict “future increases in storm-related [economic] and ecosystem damage for the Hawaiian Islands."
This comes after the Eastern Pacific recorded its most energetic hurricane season on record.
Feb. 10: Strongest wind ever recorded in Hawaii
At 4:40 p.m. local time, a gust of 191 mph was clocked atop the summit of Mauna Kea on the Big Island. If verified, this would be the highest wind gust ever recorded in the Aloha State, according to meteorologist Jesse Ferrell at AccuWeather. It accompanied one of the strongest winter storms in recent memory to hit the state.
Feb. 10: Record low
According to Jonathan Erdman at Weather.com, the storm might also have set the state’s record low temperature. The summit of Mauna Kea fell to somewhere between minus-10 and minus-12 degrees Celsius (10.4 to 14 degrees Fahrenheit), depending on which sensor is most accurate, hinting at a chance the summit dipped below the previous record of minus-11.1 degrees C (12.02 degrees Fahrenheit) in May 1979.
Potential record snow
There is debate as to whether snow fell at elevations as low as 6,200 feet over the weekend. Video emerged from Maui showing a ground blanketed in wintry precipitation, while the state Department of Land and Natural Resources says snow made it as low as the Polipoli Spring State Recreation Area.
However, there’s a chance that this is graupel — akin to small hail or sleet pellets — and not true snow. Indeed, the atmosphere appeared significantly too warm for it to fall, based on a weather balloon sounding taken that morning on the Big Island. It’s unlikely that snow could have penetrated much below 8,000 feet.
The Pacific Commercial Advisor reported that snow fell at an altitude of 6,000 feet, dusting the Haleakala Crater, on Feb. 19, 1903.