ORLANDO, Fla. – Over the weekend, Florida witnessed another train of heavy rains and thunderstorms associated with a frontal boundary dipping southeastward across our area.
Hot on its heels, we had the densest and most potent push of cold, polar air from deep up north in the Canadian provinces slide through the neighborhood.
We set a number of different cold weather temperatures through town, to include overnight low temperature records and even the “coolest” warmest afternoon highs in some spots.
As we work our way through Wednesday together, things will start to warm up. Into Thursday and toward the weekend, Florida will be right back to its more staple weather pattern of 60s in the morning 80s in the afternoon.
That’s because the trough in our polar jet stream is quickly accelerating eastward into the Atlantic Ocean taking all the cold air with it. Troughs go through multiple phases that help to speed up or slow down how fast the cold air trapped inside moves and flows.
From there, we welcome the return of ridging from down across the subtropics northward. These ridges extending their grasp up into higher latitudes drive warm air from the equator with them.
We’ll be right back into a more textbook setup that we’re familiar with in Florida.
When is the next cold snap coming? Will Thanksgiving be chilly? Will we be in for a cold Christmas? A pseudo-white Christmas, perhaps?
The over-arching question is will these massive drops in air temperature and freezing conditions become a more frequent occurrence in Central Florida?
I have to openly say, there’s a pretty decent chance they do. But with a catch.
It all hinges on the jet stream.
For those who’ve only heard the term jet stream but never quite understood what it truly was, it’s a belt of very fast moving winds that usually flows west to east across the mid-latitudes of the northern hemisphere. It’s driven solely by temperature.
Extreme cold in the polar and arctic regions up north, dueling against the warmer tropical conditions that extend out from the equator and the tropics where we watch for tropical storms/hurricanes during the summer time.
That’s precisely why the jet stream is almost nonexistent, if not weak, when we’re tracking hurricanes in the summer. Then, notice as cold fronts become a more commonality for all of us alongside freezing temps and snow, there are no hurricanes to be found.
When the jet is in balance, it flows in a more zonal pattern. This means due west to east generally around the globe.
If something disrupts the flow, or there are periods of weakening in different sections of the continuous belt of wind, that’s when we get expansive troughs that reach down south and ridges that climb from the tropics northward into the upper latitudes.
Could we start to see more stubborn troughs and ridges? Could we begin to see more hurricane seasons like this one, where all tropical systems avoid the U.S. thanks to amped up troughs and ridges?
There’s some science that suggests yes, things are actively evolving.
We’ve all heard about the poles and the arctic warming. There’s a term called “modification,” not weather modification as you see floating around social media, but how air can evolve and change overtime based on where it comes from to where it goes.
The same concept can be applied when talking about arctic warming. The region is generally characterized by cold, dry, frozen conditions year-round with some variability as we slip between spring, summer, fall and winter.
But, as the upper latitudes warm, this helps expedite the melting of sea ice, which also helps keep the ocean temperatures tame like ice cubes in a cold beverage. Less ice, warmer drink.
Ice also acts like a reflector. The sunlight bounces off of it and heads back up toward our atmosphere. With less ice, there’s more darker ocean water. You ever hear how you should try to avoid wearing dark shirts or clothes when it’s incredibly hot out? Water is a great insulator of heat, the same way a black shirt feels much hotter when you step out into open sun.
With less ice, more sunlight gets through, which warms the water faster. With less overall cold air up north to duel with the warmth building over the tropics, our jet stream slowly but surely becomes weaker and frayed.
This begins to push stronger troughs of cold air south, and more warm episodes north. The jet being able to stay strong, dominant and flow west to east shows the Earth trying to stay in balance. With warming occurring as far north as the arctic, just adding more heat to the mix, it creates instability. The same mechanism that drives our daytime thunderstorms in the summer.
So, we could end up seeing far colder periods in the state of Florida and across the south over time. Sea ice has been observed to be deteriorating up north, and slowly exponentially increasing as it does so based on recorded data. Eventually the modification we see in polar air masses over Florida, will start to take its course up there.