Winter Weather Phenomena Causing Extreme Weather

For most of us, this is the time of year we typically experience the most extreme winter weather, but winter has looked a little different this year, as extreme weather continues to hammer portions of the country with a variety of strange events from atmospheric rivers to falling-iguana warnings. These strange and sometimes beautiful events can create some of the most awe-inspiring nature scenery but can be dangerous and deadly. Here’s a quick look at the most interesting winter weather phenomena we’ve experienced already this season and how they’ve impacted regions around the country.

Atmospheric Rivers

California is being pummeled right now by a series of deadly storm systems called atmospheric rivers. Atmospheric rivers are relatively long, narrow regions in the atmosphere that transport water vapor out of the tropics. When an atmospheric river make landfall, it typically releases the water vapor as either rain or snow. Atmospheric Rivers are not a new phenomena and are frequently relatively weak systems that can be counted on for contributing to annual precipitation, but these storms can produce massive amounts of precipitation creating flood risks, particularly in the western United States when a barrage of these storms affects the same area for weeks.

This season, a series of seven different atmospheric rivers have hit California since New Year’s Eve and just this past weekend, there were eight million people under flood watches in coastal California. The flooding, mudslides and landslides from these storm events have oversaturated land and caused more than 400 landslides since December 30 and nearly 20 storm-related fatalities have been reported across the state since the end of 2022, which is higher than the death toll from the state’s wildfires over the past two years. Fortunately, it appears much of California will be getting a reprieve through the end of the month as the main storm track shifts further north into Oregon and Washington.

Lake-effect Snow

On the other side of the country, the Great Lakes region of the country is none-too-familiar with the winter phenomena of lake-effect snow and it’s the only place in the country where this happens. Upstate New York and the cities of Rochester, Buffalo, and Syracuse are the most common targets of these massive snowstorms. Lake-effect snow happens when cold air, typically from Canada, moves across the Great Lakes and as it passes over the lakes’ unfrozen and relatively warm waters, the warmth and moisture is transferred into the atmosphere. As that lower portion of a storm system becomes warmer, the less dense air rises and leads to snow on the U.S. side of the Great Lakes. Just last month over the holidays, Buffalo saw lake-effect snow which brought more than 50 inches of snow to some areas, and nearly 50 deaths as a result.

These same weather systems can also impact lakeside communities with thick ice, and just a few weeks ago, houses along the shores of Lake Erie were literally encased in up to three inches of ice as a result of gale-force winds and 15-foot waves from a strong weather system passing over the lake.

Falling Iguanas

The holidays also brought about unusually cold weather in Florida and resulted in Miami’s office of the National Weather Service issuing an unofficial warning for falling iguanas.

According to the Florida Fish and Wildlife Conservation Commission, this is a real phenomenon that happens when temperatures fall into the 30s and 40s. When the cold-blooded iguanas get too cold, they fall into a catatonic state and literally drop from the trees. These cold-blooded reptiles typically rely on a warmer air temperature to regulate their own body temperature, and these cold snaps leave Florida residents dodging falling iguanas until temperatures rise back into the 50s.

Bomb Cyclones

While bomb cyclones aren’t particularly rare, this oddly named weather phenomenon is a quickly strengthening weather system and has recently impacted portions of California along with the atmospheric rivers. A bombogenesis, or bomb cyclone as it is commonly called, happens when the barometric pressure drops at least 24 millibars in 24 hours; basically, the lower the pressure goes, the more powerful the storm. The bomb cyclone moniker has been used for more than 80 years and was formalized in 1980 with the publishing of an article in the American Meteorological Society’s Monthly Weather Review. In the article they called it a bomb because it develops “with a ferocity we rarely, if ever, see over land.”

A snow bomb cyclone in late December which impacted residents and businesses from the Midwest, southern and eastern states brought holiday travel to a standstill and knocked out power for more than 1 million customers. Earlier in January, the remnants of a bomb cyclone storm that struck off the California coast brought up to 48 feet of swell and sustained winds of more than 70 mph, causing damage to homes, businesses and tourist attractions in Santa Cruz.

With plenty of winter left we will continue to see a variety of weather across the US through into early February. Fortunately, an upper-level ridge will build over the western states ending the barrage of storms and allowing this area to recover a bit. Further east, several winter storms will spread moderate to heavy snow across portions of the Great Lakes and Ohio Valley, with each of them tapping into deeper moisture to the south continuing the threat for winter severe weather events. At the same time, the major cities of the Northeast U.S. will continue their relatively snow-free winter as rain spreads up the coast with these systems.

So, while we expect snow and cold in the winter, it’s important that to have awareness of the potential challenges from extreme weather events, which are not likely going away. Business and civic leaders need to be prepared for ongoing challenges with these strange, but extreme weather events, not only in the context of public safety, but also the impact on business operations and productivity.