This content was originally published by the Longmont Observer and is licensed under a Creative Commons license.
Forecast Discussion:
Our temperatures dropped on Friday the 13th, and, unfortunately for all, some of the smoke from northern California trekked across the western US and made visibility drop. I clearly smelled the smoke for an hour or two outside. As the sun set, the mountains were definitely obscured. Figure 1 is a smoke analysis from NOAA showing the thin tongue of smoke that was headed our way. It isn't very extensive and the next front should push it to the south on Saturday with our yet cooler and gustier air.
Figure 2 shows our front pushing far south of the state by Saturday PM. The tight lines (yellow) over Colorado means there is a strong pressure gradient. That is where the winds come from. Figure 3 is the upper air chart at that time and the trough is just past us later Saturday. The back side of a trough often has sinking air - so we won't see any rain chances at all by evening.
In the longer range:
A ridge dominates the weather from Sunday to Thursday. By Friday this week, a much bigger west coast trough begins to approach (the distance between the blue ridge axes is narrower than the width of the U.S. - so these features will move to the east) giving us a chance of rain around Saturday - a week from now. Mild weather is the story (non-story) for the week.