Now we know why polar stratospheric clouds (PSCs) have suddenly exploded. According to NASA's MERRA-2 climate model, temperatures in the Arctic stratosphere just hit a 40-year record low for the month of December:
Cold air in the stratosphere is exactly what PSCs require. Normally, the stratosphere has no clouds at all. But when the temperature drops to a staggeringly-low -85 C, widely-spaced water molecules coalesce into ice crystals and PSCs begin to form. Their aurora-like colors make them the most beautiful clouds on Earth.
PSCs are normally confined to the Arctic where the stratosphere is coldest. During this week's extreme cold wave, the clouds descended all the way to mid-latitudes. Here they are over Locarno,Switzerland (+46N):
Taken by Branca Cristina on December 22, 2023 at Locarno, Switzerland
"I saw these clouds for the first time on Dec. 22nd," says photographer Branca Cristina. "The colors were amazing!"
Meteorologists on social media channel X are posting weather models about the increasing threat of a so-called sudden stratospheric warming (SSW) over the Arctic, which could unleash wintry weather across the eastern half of the US in the new year.
"A textbook sudden stratospheric warming event looks to be unfolding," private weather forecaster BAM Weather (BAMWX).
Judah Cohen, Ph.D. and an atmospheric and environmental scientist who studies the polar vortex, told FOX Weather an SSW event takes "about two weeks for the effects of the sudden stratospheric warming to impact our weather."
Cohen expects that cold air will pour into the Lower 48 in the new year, although the specifics of the event remain uncertain.
Comment: Sudden Stratospheric Warming events are never good. History has shown they indicate the increasing destabilization of the jet stream patterns over the northern hemisphere, bringing catastrophic weather with it.
This season's strongest cold front brought heavy snowfall mainly on the Sea of Japan side of the country on Friday. The snow is expected to get heavier on Saturday, and the Japan Meteorological Agency is warning people to be careful about accidents and transportation disruptions caused by the heavy snow.
According to the agency, the amount of snow that fell in the 24 hours ending at 11 a.m. Friday was 73 centimeters in Iwamizawa, Hokkaido, the largest snowfall in the city's recorded history. Even on Honshu, Itoigawa, Niigata Prefecture, saw 58 centimeters; Shirakawa, Gifu Prefecture, saw 54 centimeters; and Ono, Fukui Prefecture, saw 53 centimeters.
Thousands of residents in Australia's eastern state of Queensland remained without power after a "very dangerous" storm swept through the region for the second time in 12 hours, local media reported on Sunday.
Storms are expected to continue along the entire Australian east coast until Boxing Day due to an unusual weather pattern, the Australian Broadcasting Corporation said, citing the Bureau of Meteorology (BOM).
A storm cell that stretched from the Darling Downs to northern New South Wales brought heavy rain, strong winds, and hail.
Thunderstorms have downed 120 power lines, leaving approximately 57,000 customers without power, said a spokesman for Energex, a Queensland government-owned electricity company that serves 1.5 million homes and businesses in the southeastern part of the state.
Heavy rainfall in the Zgharta region in northern Lebanon has caused a landslide, killing four Syrian refugee children.
The Lebanese Civil Defense sent out rescue missions to help those trapped in their vehicles or homes, remove mud and rocks from the roads, and release water from flooded areas.
The children were killed after the ceiling of a room made of corrugated iron collapsed on them during heavy rain.
The quantity of rain that fell on Saturday along the Lebanese coasts and inland areas is being blamed for the tragedy.
MP Halima Kaakour nearly drowned while she was swimming in the sea during the stormy weather.
She was rushed to the hospital after swallowing a large amount of water.
The low-pressure system affecting Lebanon will last until early Monday morning before gradually subsiding.
As winter tightens its grip across the globe, South Korea has found itself in the throes of its most intense cold wave of the season. On December 22, 2023, the nation was plunged into a deep freeze, with temperatures plummeting to perilous lows and snow blanketing the landscape in a scene as disruptive as it was picturesque. The Korea Meteorological Administration (KMA) recorded some of the season's harshest conditions, with mercury levels dropping below minus 20 degrees Celsius in areas of Gangwon Province and the nation's capital, Seoul, witnessing a chilling minus 14.7 degrees Celsius.
In an extraordinary turn of events, the frigid weather forced Jeju International Airport to suspend runway operations for over seven hours, leaving thousands of travelers in limbo as 286 flights were canceled. The heavy snowfall, which reached more than 30 centimeters on Jeju Island and up to 60 centimeters in western coastal regions, created an almost standstill condition, affecting daily life and mobility significantly.
Patrick Thorne Inthesnow.com Sat, 23 Dec 2023 12:43 UTC
Stormy weather has brought hurricane force winds and some huge snow accumulations to the Alps, with ski areas in Austria appearing to see some of the most extreme weather.
The Zillertal Arena (pictured) reports it has had a metre of snowfall in 24 hours, while other ski res including Kitzbuhel and Obergurgl largely closed by hurricane force winds giving blizzard conditions.
The heavy snowfall is expected to be short lived with the forecast now for clear skies and sunny week through the Christmas Holidays and up to New Year.
In a rare and extreme weather event, Yantai and Weihai cities in East China's Shandong province experienced a severe cold wave accompanied by heavy snowfall this week.
The snowfall created a unique and picturesque landscape, with netizens likening it to an Arctic expedition.
From Tuesday to Thursday, Yantai weather station received a snowfall of 28.6 millimeters, with a snow depth of 52 centimeters, breaking historical records since meteorological documentation began in 1951.
As of Friday, Wendeng district in Weihai reported a snow depth of 74 centimeters, setting a record for the deepest snow accumulation in Shandong province.
Comment: Sudden Stratospheric Warming events are never good. History has shown they indicate the increasing destabilization of the jet stream patterns over the northern hemisphere, bringing catastrophic weather with it.