TULSA, Okla. — This prolonged and historic Arctic blast has brought the most widespread snow cover to the U.S. in decades.
It left several inches of snow on the ground, not just here in Tulsa, but for hundreds of miles around.
While the sun’s rays can aid the melting process, even when we’re below freezing, it also reflects back rays that would otherwise warm the surface.
All of this snow is a heat sink, acting to keep the air around it colder than it otherwise would be.
Just think of all of Oklahoma being put in a cooler with a pack of ice beneath us. Naturally, you’d expect it to be colder.
At night, it makes it colder since the ground does not give back its usual warmth. And during the day, even as the atmosphere above us warms, that added heat goes to snow melting – a process that takes away from the actual ability of the air around us to warm as readily.
If that snowpack goes for hundreds of miles, it’s even harder to transport warmer air into the region as fast.
That is why Thursday’s high would have been above freezing, and for the next two afternoons, our projected highs are about 10 degrees colder than they otherwise would be without snow on the ground.
Fortunately, as we melt that snow, temperatures are less impacted by the lessening amount of snow.
Before we know it, we are back on track, which will certainly be the case next week as temperatures rise back above freezing.
Aside from cooling the air around us, and making it just generally brighter outside, there is one more impact that could be beneficial as we head into the weeks to come.
The longer that Arctic air sits over the northern Gulf of Mexico, the more it cools the water – which has occurred by several degrees over the past week. This enables less evaporation and ultimately, slightly less moisture transported northward when a southerly fetch sets up – this can help to limit severe weather potential in the short-term.
However, this is no guarantee severe storms wouldn’t crop up in our region between now and early March if the pattern is right to compensate for that.
With a higher sun angle by this point in the year, we can get more efficient melting. In a matter of days, the snow will be largely gone and much warmer temperatures are forecast.