Monday, October 20, 2014

Initial Analysis Suggests Snowy Winter for Midwest, Plains

An initial examination of the conditions observed so far in October indicates we may see a snowy (or at least active) winter in the Midwest and Plains.

The first factor going into this idea is one about cyclic weather patterns. The graphic above shows precipitation anomalies from September 20th of this year to as close to present day as I could get, in this case October 18th. Blues and purples correspond to wetter than normal conditions over this time period, while greens and yellows indicate the opposite. According to this image, we've seen the primary storm track set up shop over the Midwest and Great Lakes into the Central Plains, as the stretch of blues and purples show. The North Plains observed dry conditions, as did most of the Eastern Seaboard. The reason I'm discussing precipitation anomalies across the end of September into the first half of October is due to how the new Lezak Recurring Cycle (LRC) looks to be setting up.

The Lezak Recurring Cycle, developed by meteorologist Gary Lezak, states that the weather pattern which develops around October into November may 'repeat' on a steady interval, usually 40 and 60 days between 'cycles'. For instance, if we saw a very strong storm system in early October, and the cycle length was later determined to be around 52 days, we might expect that same piece of energy associated with that October strong storm to return in late November or early December. The same happens with ridges of high pressure, minor storm systems, etc.

Gary Lezak indicated a while ago that we were beginning to morph into the new LRC pattern, so it's quite plausible, if not likely, that the precipitation track in this image may show up again later on in November and early December, possibly bringing some wintry weather along (depending on the synoptic set-up at that time, of course).

The image above shows precipitation total projections for the next week or so on the top panel, precipitation projections for 7-14 days away, and precipitation anomalies for that first week's period. Glancing over the top image, it looks like the storm track is expected to shift north into the Plains in coming days, good news for snow fans in that area for when the LRC repeats later on this year. After that, the long-long range precipitation outlook in the middle panel suggests a return to a Midwest storm track. Today's updated precipitation outlook favors more of a Plains track, but the general idea of a rejuvenated Central US storm track is clear, and is something that will need to be watched closely as the LRC cycles later on in the winter.

To summarize:

- Indications from the Lezak Recurring Cycle currently favor a snowy winter ahead for the Midwest and Plains.