The Pacific Northwest is often associated with fog and dreary weather, but in fact it is a region full of meteorological activity. Many weather systems that reach the central and eastern United States actually have their roots in the Pacific Northwest, so a prudent forecaster will have a working knowledge of weather systems from this area and be able to monitor how they evolve.
For this issue’s puzzle, at least 2 major frontal systems will be found; one is easy and the other is difficult. To locate them, stick to the basics. Use the principle of greatest temperature contrasts to estimate frontal positions, refining them based on troughs, wind shift lines, and other air mass contrasts. There are a few high-altitude stations on this map, so avoid being fooled by their cool temperature readings. Start out with light annotations in pencil, erase them as necessary, and then darken the details once you’re confident of the big picture.