It’s been a comfortable couple of days around the Valley and guess what! There’s more to come. Looks like we’ve shaken the heat and humidity out of our system for a while as a “troughy” pattern takes over for the rest of September.
When looking at mid-range temperature forecasts, there are certain charts we like to use to analyze what the temperature trend will be over the next several weeks. One of my favorites is the “Ensemble 500mb Height Anomalies.” Let’s break that one down word by word..
Ensemble – The average of many different model runs starting at the same time with slight tweaks to the initial conditions.. this gives a better idea of long term trends as it averages several runs
500mb – The 500 millibar pressure level of the atmosphere (usually 5400-5800m above our heads)
Height – The height of the 500mb pressure level at any given spot.
Anomalies – How far off “normal” in either direction the heights are (Blue/Purple = Negative Height Anomalies = Seasonably Cooler Air .. Yellow/Red = Positive Height Anomalies = Seasonably Warmer Air)
Here’s the trend for the rest of September in a nutshell: Blue/Purple=Cooler than normal, Yellow/Red=Warmer than normal
9/13
9/17
9/21
9/25
So, to sum things up, expect more of this comfortable dry air for the rest of September and some chilly mornings as well.
Fall officially starts Next Saturday, September 22 at 9:49am
- Ari Sarsalari
