Longwave pattern shift; MJO active again

After what has been a very wet month for the Pacific Northwest, the pattern may finally be shifting to bring heavier rains to California. All of the storminess as of late been directed at the coast from Eureka northwards, and areas from the central Bay Area southwards have been left completely dry. An active phase of the MJO–complete with a strong Kelvin Wave progressing across the Pacific–is currently developing. The maximum effect of this active phase won’t be felt until about a week from now, but downstream amplification of the jet stream could occur as soon as day 5. I mentioned the potential existed for an active early December in my Seasonal Outlook back in October, and it appears that this may come to fruition. More on this in coming days. Rain and wind…with possible lower snow levels and chances of thunderstorms, may be in the offing day 5 and beyond. Active weather will continue in the Pacific Northwest. Winter will make itself known where it has not already.