We often joke that Maryland can experience all four seasons in a single day—but after the last 24 hours, that joke might actually be true.
Temperatures soared to 84°F Wednesday afternoon before plunging to 34°F by Thursday afternoon—a staggering 50°F drop in just one day.
So how does something like that happen?
The answer lies in a large-scale atmospheric pattern called Rossby waves, named after meteorologist Carl-Gustaf Arvid Rossby, who first described the phenomenon in 1939.
Rossby waves are the large bends or meanders in the jet stream. When the jet stream dips southward, meteorologists call it a trough, which typically allows colder air to spill southward. When the jet stream bulges northward, it forms a ridge, which usually brings warmer air northward.
If you look at the jet stream pattern yesterday, our region was clearly sitting beneath a ridge, allowing that early taste of summer warmth. Today, the pattern shifted dramatically, placing us under a trough, which ushered in much colder air.
These dramatic temperature swings happen more often in March because the atmosphere is in a seasonal tug-of-war. As the sun angle increases and the southern U.S. begins warming up, winter’s cold air still lingers to the north. The jet stream acts as the battleground between those two air masses—leading to the wild temperature swings we often see this time of year.
In other words, March is peak “weather whiplash” season.
