United States Faces Widespread Extreme Weather

The United States is experiencing, or is forecasted to experience, a variety of extreme weather conditions across nearly all regions. Hawaii has begun to receive days of heavy rainfall. The Southwest anticipates sustained record-high temperatures exceeding 100 degrees Fahrenheit (38 Celsius). Northern Great Lakes states are expected to receive significant snowfall from two storm systems. Additionally, the Midwest and East are bracing for a return of Arctic temperatures associated with the polar vortex.

This forecast of extremes follows a period of weather volatility in the East, where Washington, D.C., experienced a record-breaking 86 degrees Fahrenheit (30 Celsius) on Wednesday, followed by snow on Thursday. Meteorologist Marc Chenard of the Weather Prediction Center noted that most parts of the country would see general shifts between cold and warm conditions.

Former National Oceanic and Atmospheric Administration chief scientist Ryan Maue expects extreme weather in all 50 states.

Persistent Triple-Digit Heat in Southwest

A heat dome is expected to form early next week over the Southwest, leading to triple-digit temperatures that are unusual for this time of year. Phoenix is forecasted to reach 98 degrees Fahrenheit (almost 37 Celsius) on Tuesday, followed by 103, 105, and two days of 107 degrees Fahrenheit (almost 42 Celsius).

Historically, Phoenix has not reached 100 degrees Fahrenheit before March 26 and typically experiences its first 100-degree day in early May. The weather service has issued warnings due to the potential impact of this early heat, as residents are not yet acclimated. Los Angeles has already seen unusual 90-degree Fahrenheit weather in March.

Arctic Cold Moves North

Around the same time the Southwest experiences heat, the polar vortex is projected to bring frigid air deep into the Midwest and East, potentially extending to parts of the Southeast. Minneapolis is expected to have low temperatures around zero degrees Fahrenheit, and Chicago is forecast to be in the single digits on Tuesday. Temperatures in the teens and 20s are anticipated in the Northeast and Mid-Atlantic the following day, with Atlanta potentially dropping to the 20s.

Dual Snowstorm Impact

Two consecutive storm systems are predicted to affect the country's northern tier and Great Lakes region. The first storm is expected on Friday, followed by a second from Sunday into Monday, with the potential to dump 3 to 4 feet of snow in some locations.

The larger second storm system is projected to intensify rapidly with a sharp drop in barometric pressure, classifying it as a bomb cyclone. Such development over land is unusual, as bomb cyclones typically gain energy from warm ocean waters. This particular event is expected to draw power from the polar vortex.

Conditions in Alaska and Hawaii

Hawaii is currently experiencing an atmospheric river, leading to persistent heavy rain and significant flooding concerns, with Oahu under a flash flood warning. Alaska, while typically frigid this time of year, is forecasted to be approximately 30 degrees colder than its usual temperatures.

Jet Stream Anomalies and Climate Connection

The underlying cause of these varied extreme weather events is attributed to an unusual pattern in the jet stream. The jet stream, which guides weather systems from west to east, is exhibiting near-vertical plunges and ascents. This pattern leads to significant weather extremes occurring in close proximity. Storm fronts originating from the Pacific are pushed north by high-pressure heat domes in the Southwest, ascend the jet stream's elevated path, and then pull cold Arctic air southward.

Numerous studies have linked unusual jet stream and polar vortex activity to reductions in Arctic sea ice and human-caused climate change.

Despite the current extreme forecasts, the first day of spring on March 20 is expected to mark a period of recovery.