Houston and the Polar Vortex

Snow last Sunday in Texas
Snow last Sunday in Texas

I’ve had questions about the Polar Vortex and how it may affect the rest of the month.

Without getting into a lot of science, the Polar Vortex (which hasn’t really been a player the last two years) is that cold pool of air at the north pole that can’t escape because the winds are moving so fast. But if a sudden surge of warm air intrudes (and it has) then those winds will weaken, buckle and allow the cold air to move south. Here’s an example of how it works with the strong PV on the left and weaker one on the right:

On the left, a strong PV keeps the cold air locked up at the pole. On the right, a weak PV allows the cold air to surge south.

And this shows an example of the intrusion of warm air:

This shows how the Jet Stream weakens and buckles, allowing the southerly surge of cold air

Where is the sudden warm surge coming from that is weakening the Polar Vortex? According to Judah Cohen, Ph.D., who writes extensively on this and other climate connections here, attributes this to our warming world. He notes that 2020 will likely go down as the WARMEST year on record:

2020 is likely to be the WARMEST year on record across the globe

What’s the forecast?

Looking at just the GFS (American) model, it’s easy to see these surges of cold air into the United States through the end of this month, especially for the East, although Texas may get a taste of this, too!

American model showing cold temperatures for the US courtesy Tropical Tidbits
American model showing cold temperatures for Texas courtesy Tropical Tidbits

I see this as more ‘cold snaps’ for us than deep, prolonged cold. I forecast that to be more of an East Coast issue. However, the long term GFS does keep us in the 40s for highs and 30s for lows the last week of the month (January 25th - 29th):

Cold temperatures from January 25th to January 29th

Not too many “freezing” temperatures there, but keep that jacket handy. And there is February to get through which in the past has been prime for an ice storm!


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About the Author:

KPRC 2's chief meteorologist with three decades of experience forecasting Houston's weather.