After a blizzard warning in Hawaii over the weekend, the island state begins Monday with widespread flash flood alerts.
Around a foot of snow was expected in the island state, according to the National Weather Service (NWS) on Saturday, some 1,347 days since the last blizzard warning. The peaks of the Big Island’s dormant volcanoes, Mauna Loa and Mauna Kea, were capped with snow.
Sunday brought state-wide flood watches and warnings of winds up to 100mph on Hawaii Island. The heaviest rain of up to three inches per hour fell in the southeast of the Big Island and parts of Maui.
A subtropical cyclone, called a “kona low” in Hawaii, will linger over the state on Monday, NWS reported, with total rainfall amounts in the 10-15 inch range forecast and isolated areas of up to 25 inches of rainfall.
The weather service warned that the rainfall could lead to catastrophic flooding and affect areas that are typically drier, such as the south and west slopes of each island.
While Hawaii was under the rare threat of a blizzard, flurries were nowhere to be found in more typically snowy climes. Denver, Colorado has broken an 87-year-old record for number of days without snowfall, and it’s a week out from surpassing a 134-year-old record of 235 consecutive days without snow. Denver hit a high of 73F (22.8C) on 4 December – tying a record set in 1973.
It’s a similar situation across large areas of the Rocky Mountains, and in western states which have been suffering from a prolonged mega-drought driven by the climate crisis. The winter snowpack in the mountains is an important water source for the rest of the year.
In the Canadian province of British Columbia, the town of Penticton experienced its highest December temperature in recorded history last week at 72.5F (22.5C). Salt Lake City, Utah had no snow throughout November, for only the second time since 1976.
In Montana, wildfires tore across prairies last week after record heat and high winds. Several dozen homes, along with businesses and grain elevators, were destroyed in the rural community of Denton, three hours north of Billings.
The topsy-turvy set of record-breaking weather forecasts were being attributed to a stagnant jet stream and the effects of a La Niña weather pattern from cooling waters in the equatorial Pacific.
The jet stream, the river of air that moves weather from west to east, has been stuck, meaning low pressure on one part of the stream is bringing rain to the Pacific Northwest, while high pressure hovering over about two-thirds of the nation produces dry and warmer weather, Brian Hurley, a senior meteorologist at the National Oceanic and Atmospheric Administration’s Weather Prediction Center told AP.
This is a typical weather pattern with a natural La Nina weather oscillation, he also said. The flip side of El Nino, a La Nina is a cooling of parts of the central Pacific Ocean that changes weather patterns across the globe. La Ninas tend to bring more rain to the Pacific Northwest and make the South drier and warmer.
These bouts of extreme weather happen more frequently as the world warms, said meteorologist Jeff Masters. But scientists haven’t done the required study to attribute these events to human-caused climate change, AP reported.
The NWS’ Climate Prediction Center says that La Niña is likely to continue through the Northern Hemisphere winter into 2022 (about a 90 per cent chance) and into spring 2022 (around a 50 per chance chance during March-May).
AP contributed to this report