01/23/2026
~Weather Classroom: Baby, It's Cold Outside~
As we're going through this period of extreme cold—especially considering the unseasonably warm weather we've been experiencing off and on this winter—I'm sure many of you are wondering what in the world is going on, so I decided to give this quick breakdown of the causes of not only the warmer weather, but also the cause of sudden, extreme drops in temperature.
It all depends on two factors: The Polar Vortex, and whether it's a La Niña or El Niño season.
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What Is a Polar Vortex?
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A Polar Vortex is a permanent mass of both extremely cold air and low pressure that exists in the stratosphere at both poles of our planet.
When the Polar Vortex remains strong, that cold air mostly sticks to the polar areas, however when it weakens, becomes distorted, or splits (called a 'wobble'), that cold air is released and carried by the jet streams to the south for the northern vortex or to the north for the southern vortex. (Depending upon the hemisphere.)
The strength and integrity of the vortices naturally shifts during winter in both hemispheres which is part of what causes winter to be cold, and the duration of its strength and its integrity is part of what determines the length of time that we experience warmer or colder weather in winter.
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What are El Niño and La Niña, and What Part Do They Play?
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El Niño and La Niña are both part of what's known as ENSO, which stands for the El Niño Southern Oscillation System. ENSO impacts rainfall, winds, and the temperatures of the surface water of the oceans which, in turn, affects the weather on a global scale.
El Niño and La Niña are opposite phases of ENSO, with El Niño causing warmer waters in the Pacific and weakened trade winds that push the warmer water to the east. El Niño also shifts the jet stream to the south which essentially prevents the colder arctic air from reaching the northern US, and this also causes stronger cloud cover over the southern US; El Niño seasons are also associated with a reduction in Polar Vortex instability. This combination results in colder, wetter weather in the southern US and warmer, dryer weather in the northern US.
La Niña has the opposite effect: It causes colder surface temperatures in the Pacific as well as stronger trade winds that push this colder water to the west, pushes the jet stream south, and is associated with an increase in Polar Vortex instability, leading to warmer, dryer weather in the southern US and colder, wetter weather in the northern US.
In short: Polar Vortex stability and ENSO go hand-in-hand, with ENSO directly impacting the Polar Vortex's stability, the direction of the flow of cold air, and the amount of precipitation experienced in winter in the northern and southern halves of our country.
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Current Weather Patterns in Our Area
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From September until mid-December, we had a fairly weak La Niña system that was responsible for the initial cold we had been experiencing due to the Polar Vortex's instability, though the fact it was so weak is why the instability was intermittent; the shift from an unstable to a stable Polar Vortex is why we were bouncing between temperature extremes.
Now, La Niña is on the retreat and we're entering what's known as ENSO-Neutral conditions where neither El Niño nor La Niña are strong enough to have a particular impact on the weather, and this also leads to a more stable Polar Vortex.
*HOWEVER,* ENSO-Neutral conditions don't mean that the vortex can't weaken, wobble, or collapse, and the currently frigid temperatures are the direct result of the initial wobbling of the vortex. The wobble has caused it to stretch and push arctic air down into the northern US, and what we're experiencing now is the initial blast of that arctic air; this disruption as well as a potential collapse of the vortex will prolong the cold temperatures, although there will be periods of somewhat warmer (but still quite cold) temperatures as well, with temperatures from Tuesday onward alternating between the mid-to-upper teens and low-to-mid 20s, and then reaching the upper 20s to low 30s by next Sunday until the end of my current forecast models which end on the 7th.
Currently, the disruption of the vortex and its potential collapse are expected to sustain the cold weather we're experiencing, and the generally cold temperatures are expected to persist *at least* into early-to-mid February.
If the disruption is maintained, the cold will persist at least into mid-to-late February, however if the vortex collapses entirely, this will again lead to more frigid temperatures, and the cold weather could continue even into early Spring.
Climate change is also affecting both winter and summer weather around the globe, and I will be breaking down those impacts at a later date in another edition of Weather Classroom.
I hope you all enjoyed this edition of Weather Classroom and have learned at least one new thing as a result!
Do your best to stay warm out there, and pay especial attention to your ears, nose, fingers, and toes. With such cold temperatures and frigid wind chills, frostbite can occur in as little as ten minutes of exposure; if any of those areas are numb, you're in stage one of frostbite!
Put on those ear muffs or pull that stocking cap down over your ears, wear a scarf or some other covering over your face, a pair of nice, warm gloves, and warm, thick socks (or double up on thinner pairs)!
Have a good weekend, everyone!
