Key Highlights
- No snow expected on Thanksgiving in Philadelphia but winter may arrive early.
- Astronomical event could bring colder temperatures to the region before holiday weekend ends.
- Stratospheric warming event could significantly impact weather patterns, leading to potential cold air outbreaks.
No Snow on Thanksgiving but Winter is Coming: Philadelphia’s Weather Forecast
The much-hyped snowfall on Thanksgiving in Philadelphia may be a myth. According to the latest forecast from meteorologists at the National Oceanic and Atmospheric Administration (NOAA), the region will likely avoid a white holiday this year.
While the abominable snowman balloon making its way down the Ben Franklin Parkway during the 105th Thanksgiving Day Parade on Thursday, November 28, 2024, was an exciting sight for parade-goers, it seems that real snow might be a distant memory. Nevertheless, forecasters are warning of an impending change in weather patterns with a potentially rare event unfolding.
Potential Winter Arrival
Despite the lack of snow on Thanksgiving, meteorologists at NOAA’s Climate Prediction Center have observed increased chances of below-normal temperatures and above-normal precipitation from Thanksgiving Day through December 1. The exact nature of this weather change remains uncertain, with some experts cautioning against taking social media predictions too seriously.
Stratospheric Warming Event
“The observed snowfall is inversely proportional to the hype,” said Judah Cohen, a polar scientist and seasonal forecast specialist. He pointed out that numerous snow mentions have appeared on X and websites, indicating heightened interest in winter weather patterns. The next week should generally be uneventful, save for rain Tuesday night possibly into getaway Wednesday when highs are forecast to reach the 60s.
However, a major stratospheric warming event could chill December.
According to Laura M. Ciasto, a NOAA meteorologist, such events have occurred on average about six times a decade, but having one this early would be quite rare. “If it does occur,” she noted, “it will be the second time in records dating to the early 1950s that it has happened this early.”
The European forecast model has consistently predicted a major event, while the U.S. model has been less impressed. A major warming could result in quite a snowy February in Philadelphia’s region, with significant impacts on weather patterns.
What Causes Stratospheric Warming?
Cohen explained that upward-moving waves from the troposphere, 5 to 9 miles over the Arctic, crash into the stratosphere, 10 to 30 miles up. This can compromise the polar vortex, the west-to-east winds that lock cold air in place during winter months. When these winds slacken, the vortex can weaken and allow frigid air to spill southward.
While computer models are debating what will happen, Cohen’s early date for this event has given him pause about forecasting its occurrence. “There’s a greater chance that the jet stream will become more disrupted and dip down,” Ciasto said, bringing cold air with it.
The effects may show up anywhere from two to several weeks after the event.
The region should prepare for a potential chill in the coming days as meteorologists continue to monitor the situation closely. While snow on Thanksgiving is unlikely this year, the possibility of an early winter remains real.
