Is the polar vortex to blame for Houston's 2025 snow storm?

HOUSTON, Texas (KTRK) -- Last week, the city of Houston and much of southeast Texas received record snowfall during a rare Gulf Coast snowstorm. With this being the second time temperatures dipped below freezing this winter, many are wondering if this active winter pattern is setting the stage for an even colder February. And if the polar vortex is to blame.

First, a quick refresher on the polar vortex. The polar vortex is a region of very strong winds that form a circle around the North Pole. The vortex is located in the stratosphere, the layer above the troposphere (the troposphere is where we live and most weather occurs). In the winter, the polar vortex helps keep frigid, Arctic air trapped in the Arctic Circle within the vortex. It acts as a barrier between the midlatitudes and the poles.

However, at times the polar vortex can break down and send that arctic air farther south into Asia, Europe, and North America. A warning sign for that to happen is when temperatures warm in the region of the vortex, technically known as "Sudden Stratospheric Warming" as the change can happen in only a few days. And when that happens, it's time to keep a watchful eye on the movement of the vortex and the jet stream in the troposphere. The polar vortex was in play during the 2021 February freeze, which led to the failure of the statewide Texas power grid.

Now the current state of the polar vortex is unusually strong. And that's a good thing! That means the vortex should trap and keep that frigid cold air in the Arctic Circle. It might seem counterintuitive to hear that the vortex is strong so it won't be cold, but that's what we want!

As for the orientation of the polar vortex, it is somewhat tilted over North America. But forecasters with NOAA who monitor the vortex say that shouldn't influence weather patterns much at this point. Looking ahead to February, a sign that the polar vortex could wake up is if there's "Sudden Stratospheric Warming." That's when temperatures warm in the area of the vortex, allowing for the vortex to move more drastically, and potentially sending colder air into Asia, Europe, or the United States.

As for if the polar vortex is to blame for last week's Gulf Coast snowstorm, the answer is no. In fact, none of the cold air outbreaks so far this winter, even across the country, are linked to the polar vortex. That's another difference between the 2021 February freeze and the rare January snowstorm from last week. This winter storm that stretched across the Gulf Coast was because of a blocking pattern over Alaska that helped send the cold weather our way. Plus, this was a regional snowstorm just for Southeast Texas, not a statewide storm that would put pressure on the power grid. The polar vortex in the 2021 February freeze sent an arctic front across Texas and much of the country, which is more typical of a polar vortex event.

So last week's snowstorm serves as a reminder that Houston gets cold weather without the polar vortex. Some long-range computer models hint at a potential cool down next week or weekend, but it's still too early to be certain and forecast any impacts.

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