High Pressure: How it brings our highest highs and our lowest lows
Often you’ll hear the StormTrack Weather Team refer to high pressure in our weather broadcasts. High pressure systems move in to mid-Missouri in any weather season and tend to bring with them quiet weather and sunny skies.
But, high pressure systems can bring a multitude of different temperature schemes to mid-Missouri, depending on where these air masses originate– as we begin the transition to fall, a new type of high pressure will replace the one we felt all summer long that brought the hot & humid weather.
In the winter, Polar High Pressure systems play a key role in bringing mid-MO bitterly cold weather. These tend to follow behind powerful mid-latitude cylones which are typically responsible for heavy snowfall that we see in the winter.
These Polar High Pressure systems, which originate in northern Canada near the Arctic Circle, bring such cold air because they are composed of very dense, dry air that doesn’t store warmth very well, in turn keeping the air mass very cold.
Summer brings a twin of sorts… at least with naming convection. Subtropical or tropical high pressure systems, while they are still high pressure systems, are composed of a much different atmosphere. Originating in the tropics, these areas of high pressure bring the heat and humidity we feel in the summer in mid-Missouri. They also have the power to steer hurricanes in the Atlantic.
These are composed with less dense air, but are extremely rich in water vapor and that’s obvious because they hang around the 2nd largest body of water on the planet. Water has a very HIGH capacity to store heat, (kind of like a sponge for heat) and that’s one of the reasons these play a key role in HOT and HUMID weather that we experience during the summer.
What we’re seeing today is the type of high pressure that will become more common as we approach winter. While not a full Polar High, today’s High still has enough push to clear our some of the heat and humidity we dealt with last week… but as we’ve been forecasting, the Tropical High looks to make a push back later this week and into the weekend, where temperatures could top out back into the upper 80s with elevated humidity!
We’ll be TRACKING it!
-Luke
