Dry and cool conditions dominating this week
With the cold front passing through Mid-Missouri Sunday afternoon, we should expect much cooler and drier conditions dominating our area for the entire week.
Why all of a sudden are conditions becoming drier and cooler all of a sudden? Well, since the Northern Hemisphere is slowly tipping farther away from the sun’s direct rays, this is allowing for cooler temperatures to flow in. The reason these cooler temperatures are dipping into the Midwest is because our subtropical jet is shifting farther south while the polar jet begins to move south into the US. These two jets are upper level winds that act like a river. But instead of liquid water, these jets are rivers of high winds that affect our weather on a daily basis. In our case this weekend, the polar jet and cold frontal passage were directly related as they dipped into Mid-Missouri, giving not only us, but several other states near us as this rain and drastic temperature change as well. The reason I label this as drastic is because this is the first large cold front and significant dip in the polar jet for our new fall season.
What do we expect now with this passing dip in the polar jet and cold front? High pressure follows closely behind this cold front, bringing in cool and dry continental winds from the northwest. Since these winds are coming from the northwest, there will be no direct moisture transport. This is what will be starving our atmosphere of sufficient moisture for rain to develop.
These dry conditions will also hinder cloud development. Clouds have a difficult time forming if there is not enough available moisture available in the atmosphere. These clear skies will allow the sun to warm up the ground and air as well little by little all week, leading to an increase in temperatures throughout the week. Since the air has less moisture, the air will not “hold” onto the heat as well compared to when the air is moist. Think about when it is humid outside on a summer day. It feels absolutely miserable compared to a “dry” heat on a summer day.
So enjoy these dry conditions and cooler temperatures before winter sets in, because perfect weeks like theses are far and few in Missouri!
