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Message: <blockquote data-quote="Allen" data-source="post: 356430" data-attributes="member: 389">CatDaddy, first and foremost, I am not a meteorologist so I tread lightly on their turf for the most part.  But I do dabble in climate stuff, and this subject would seem to lie somewhere between meteorology and climatology.I never heard of this before now, but did read the links you provided.  First off, it doesn't take a genius to predict that we will get a "storm" of some sorts on Feb 16th, plus or minus some number of days...and plus or minus a state away, or so.  So, I would really want to hear from the people who specialize in this sort of mid-range forecasting.  One thing I do know though is that it is not uncommon at all for the first half of winter to be very unlike the second half of winter.   A few years ago we were in mid-late January and had very little to no snow across most of western ND and when the media called to ask what our spring flood season was going to look like, I would lead them through the numbers of snow-water equivalent on the countryside.  I think we were generally less than an inch of SWE.  At the end of the interview I just mentioned that while nothing is impossible, the remainder of winter would have to be pretty darn miserable to get us into the 4+ inches of SWE that puts us at risk of widespread flooding.  Well, wouldn't you know it...come February it started snowing and was in general a pretty miserable second half of the winter and put us right around 4.5 inches of SWE across many of the small watersheds in western ND.  We ended up with fairly minimal flooding, but it demonstrates how quickly things can change.  The LRC would have to be considered a complete bust for that year. That being said, there is a saying in the met world that the "trend is your friend".  Basically that means if you don't have a good reason for forecasting a significant change in the pattern, you should probably hedge your bet with a continuation of the recent patterns.  This LRC thing seems to fall under this category.When I say I dabble in climate, it's because for years I had always told people that if I plotted long-term hydro data, if you squinted really hard you would see cycles in the raw data.  So about 12 years ago, a couple mets and I tried to figure out how to get a grip on the cycles.  Here is a graph (busy I know), that shows the maximum stage for the Souris River at Minot and normalized precip.  The raw data is in the blue and yellow, and that is what you need to squint at to see patterns.  What one can also do though is put a 10-yr moving average on the data and that forms the black and red lines which clearly show a wet/dry pattern with a cycle of roughly 22-25 years from peak to peak.  Interestingly, if one looks at the red line, you note that the last peak is substantially muted in comparison the previous peaks. What you are seeing there is the flood control storage bought by the U.S. in Rafferty and Grant Devine (formerly Alameda) dams up in Saskatchewan.[ATTACH=full]55386[/ATTACH]One of the fellows I was working with on this did his M.S. on climate, and he suggested we look at various El Nino Southern Oscillation (ENSO) patterns and combine them with the Pacific Decadal Oscillation (PDO).  When you do this meteorologically, you get the following:[ATTACH=full]55387[/ATTACH]What one immediately gleans from the above is that a -PDO and a La Nina (blue lines) have a strong tendency to produce wetter than normal winters even though it isn't a slam dunk. There's definitely overlap with the other combinations.This is also found in the temperature data:[ATTACH=full]55388[/ATTACH]Note, as little as 0.5 degrees off of normal is noticeable by the layperson.  I often ask people if they think the previous month was warmer, colder, or near normal.  If the average for the month is off the historical average by as little as 0.5 degrees, about 90% of the people get it right.Oh yeah, this winter is a -PDO with a La Nina combo.  The past couple years were also La Nina, but we've now also been in a -PDO for a while, so take that for what you will.OK, I think I've gone down the rabbit trail too far, so I'll just stop now.</blockquote>

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