Jul 15, 2023

Is the Heat Wave Finally Coming to an End?

The heatwave is finally coming to an end... well sort of

by: Peyton Langford

Posted: Aug 21, 2023 / 09:37 PM CDT

Updated: Aug 22, 2023 / 09:30 AM CDT

We all know it’s been HOT outside. Constant excessive heat warnings and heat advisories day in and day out. I’m sure you’re just as sick and tired of hearing about it as we are talking about it here in the Weather Lab.

With school back in session, football right around the corner, and even Pumpkin Spice Lattes starting to make their way back into the scene, it sure seems like fall is coming so what gives? Well, it’s all based on the ridge of high pressure we’ve been talking about.

Specifically, that guy right there. Or shall I say both of those high-pressure systems? These have been responsible for the record-breaking temperatures we have seen the past 2 days and the record-breaking days to follow.

How does a high-pressure system actually raise the temperatures? Well, the higher pressure system spins clockwise. This spinning motion blows air towards lower pressure since air naturally flows from high to low. Think of it like a roller-coaster. Higher pressure means a higher hill and vice versa. The air will naturally roll down towards lower pressure. Now we’ve removed air at the surface, so what happens now?

The atmosphere is always in a balance so if you take away something, you have to replace it. The high-pressure system takes air from higher up and it sinks down to fill the air we’ve removed. The problem is, the air higher up is thinner, this is why planes have to pressurize the cabin. When you have this thin compressed air brought down to the surface the air molecules are squeezed, so they move around a lot more and at a faster rate. This faster movement of the air molecules is why the temperature raises.

It can all be boiled down to what Meteorologists refer to as the Ideal Gas Law:

On the left we have Pressure and Volume and on the right side is the number of gas molecules times the density of air times the Temperature. I know it looks complicated, but if we increase the pressure then the Temperature has to raise. Since we have a really strong high-pressure system over us, we have really high temperatures.

Well, I mentioned air flows from high pressure to low pressure, so to get rid of the high pressure we need a strong low pressure. This will come in the form of a strong low located over Northern Canada and the Pacific Northwest.

There’s a strong upper-level low off the coast of Oregon and over Quebec. These will be responsible for absorbing the high-pressure system and breaking it down. Once the ridge breaks down, we will be back in Northwest Flow, which means rain chances and cooler temperatures!

As you can see by Tuesday we’ll be back in Northwest Flow, but could see it back as early as Sunday night! The forecast calls for a 20% chance of rain Sunday and Monday, just because we’re uncertain of the timing of this cool front. Technically, it’s a cold front, but it won’t be super strong. Temperatures after the front are what we’re all here for!

Monday looks pretty nice for NWA, but this singular model doesn’t have the front passing the River Valley quite yet.

Now let’s look at Tuesday.

Now that’s more like it. It’ll start to be looking a lot more like fall… well at least close to normal temperatures for this time of year, which is 89°.

Not only will we have heat relief, but also some drought relief.

This will definitely be something to look for! I hope you’re excited about this much-needed change coming because here at Your Weather Authority, we sure are.

Thanks for reading this weather blog!

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How does a high-pressure system actually raise the temperatures?