Spring is here and a very progressive large-scale pattern is setting up for the next week. This means, like a two-faced politician, the weather will be flip-flopping with each trough passage.
Dynamic tropopause (DT) analyses are extremely useful for examining the upper-level large-scale flow. Unlike conventional pressure-level analyses (e.g., 500 or 250 mb), the dynamic tropopause cuts through or near the core of both the polar and the sub-tropical jet. The DT analysis shows not only these two jets, but also upper-level troughs and ridges, which are indicated by the wind analysis as well as locally low and high DT pressure, respectively (cool and warm colors on the image below). Thus, a DT analysis packs a lot into a single plot and is generally more useful than a single pressure-level analysis. Further, for advanced users, the dynamic tropopause is defined based on potential vorticity, so it has a number of advantages for diagnosing large-scale flow behavior, although we won't bother pulling out the heavy duty math for this post.
The GFS Dynamic Tropopause loop below shows a series of major troughs passing through the northwestern United States and clipping Utah over the next seven days. If the forecast verifies, we'll see four trough passages in the next 8 days.
What this means is a very changeable weather pattern with quick hitting snowstorms for the mountains. Bottom Line: Keep the sunblock, hardshell, and puffy jacket nearby.
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