What’s driving the warmer weather?
Mid-Missouri is once again seeing highs into the mid to lower 80s that looks to continue into the rest of the week. It's officially fall and the average high in Columbia Missouri is 77 degrees for September 25th. The main factor behind what's driving these summer-like temperatures exists due to atmospheric blocking.
A high pressure system is currently located over the Rockies with a low pressure system situated on each side creating the shape of the greek alphabetic letter Omega. This leads to the reasoning behind the name for this set-up called Omega Blocking.
Winds are being driven out of the west to southwest throughout much of the rest of this week due to the clock-wise swirling of winds around the center of high pressure. This means the air flowing into Missouri orginates from the southwest allowing for warmer air to influence our current weather.
Throughout 1991-2020, Columbia Missouri has seen an increase in seven days per fall above the average temperature. This points towards a more likely trend to continue to see warmer falls in the years to come.
A dive into the extended outlook in the 6-10 day range highlights that this blocking pattern still remains in place even though the high will move to the east directly over Mid-Missouri. this will cause above average trends during this time period.
If you have been excited for fall-like temperatures even heading into the first weekend of October then this is not the news you would want to hear. The 8-14 day time period also shows warmer than average trends as the predominant winds in the lower levels continues to highlight warmer air from the southwest continuing to be the main influencing factor for Mid-Missouri leading to above average temperatures once again.
