Most of the time as one goes up in the troposphere, the temperature cools. However, there are times when it actually gets warmer as you move through the troposphere. The troposphere is the lowest level of the entire atmosphere and it is here where all of our weather takes place. When warm air develops over cold air, it is called a temperature inversion. Cold air is heavier than warm air so when warm air begins to advance into a region of cooler air the warm air forced to lift over the cold air at the surface. This is called overrunning or isentropic lift. This can be a dangerous situation if there is enough moisture available and the surface temperature is below freezing. Ice storms can be the result when this kind of inversion sets up. Temperature inversions help create a stable atmosphere and that can lead to air pollution. The cities of Denver and Los Angeles are located in valleys. Many times, the colder air will drain into the valleys from the higher elevations. Then warm air moves on top of the cold air creating a lid and this traps the air pollution near the surface. There have been many winter mornings where Denver residents could not see the mountains because of the “brown cloud.” The pollution usually will disperse when the sun warms the surface and that allows for mixing to take place and the inversion is broken.
Weather Last Week
March 10: 31/70/0”
March 11: 20/65/0”
March 12: 21/69/0”
March 13: 23/69/0”
March 14: 31/55/Trace
March 15: 14/59/0”
March 16: 15/61/0”
Forecast discussion for the week ahead:
This is the time of year that we start to warm up more consistently, but winter isn’t quite done with us yet! We have some rain chances Friday and then again Saturday into Sunday, but if the precipitation falls at the right time (night time) we may see some snow mix in, as well. After kind of a chilly end of the week and weekend, it looks like it will try to warm up next week.