2010-2011 winter outlook

[weatherwiz]

Since eastern will be closing down hopefully everyone who made a winter outlook gets a chance to move theirs over to our new home here so we can all take a look back at them in the spring, there were some great outlooks with some great discussions and it would stink to lose them. Maybe we can get a sub-forum or something just for outlooks so they can all be in one place? Anyways this was something I came up with:

First off I really don't know all that much about long-range forecasting and I have a pretty horrible understanding of all all the global indices work together and how they each influence the patterns that setup. Nonetheless, the aspect of long-range forecasting is quite fascinating and over the past several weeks I have been working really hard at trying to understand how things work a bit more, including reading many posts on here and trying to understand them. While I fully expect to be wrong in the end I hope it turns out to be a great learning experience and I can move on from there. Anyways onto the outlook.

When assessing the potential pattern for the upcoming winter really the two major things I looked at where current ENSO state and where we are trending and the ENSO state of the previous winter. The winter of 2009-2010 which I think surprised many came in as a strong EL Nino, not just a strong EL Nino but it is the only strong west-based EL Nino on record (or at least since data post-1950). As winter progressed into spring time and then eventually summer we saw a rapid decrease in the state of the strong EL Nino, by the end of May all the Nino regions, which the exception of region 4 were already in negative departures and by the end of the summer all Nino regions were pointing towards high-end weak/borderline low-end moderate Nina conditions. The latest trimonthly ONI reading of -1.0 also confirms this.

When taking into account the recent trends of the SOI/MEI/NOI they all suggest, as well, that we are not only entering a moderate La Nina state but given the conditions in place and the expected conditions SST wise but this could end up being a very strong La Nina when all said and done. Considering where we stand now and how we still have several months to go until winter I think the chances are pretty good we see a strong La Nina by the winter.

With last winter going from one extreme (a strong EL Nino) to another potential extreme this winter (strong Nina) my next step was to go back and look at what years saw such a strong transformation. When doing so the only two other years I came across were the winters of 1973-1974 and 1998-1999. Both winters preceded Strong EL Nino's the previous winter. (Keep in mind I'm only using data dating back to 1950...eventually I'll expand my data dictionary to pre-1950).

Of the two years listed above, 1973-1974 and 1998-1999, it was really hard not to pick 1973-1974 as one of my main analog years for the upcoming winter. As mentioned above, that winter was a strong La Nina followed by a strong El Nino, that Nina also happened to be a basin-wide strong Nina and this Nina right now is shaping up to be a basin-wide strong event as well. While not perfect matches there is also some similarities within the QBO/GLAAM phase as well as the fact that we are still in a solar minimum state, however, there are some indications that this may change as things have become a bit more active as of late. There are also some matches within the NAO/AO/PDO state as well as we have entered a -PDO state and the intensification of the La Nina should help ensure the PDO stays at least weakly negative.

While the NAO/AO has been pretty much negative over the past year or so this winter they may fluctuate more between positive/negative state with the NAO/AO possibly trending more positive as the winter goes on.

Besides 1973-1974 one other year that I think match up fairly well right now is 1975-1976. 1975-1976 right now is a pretty close match when taking into account QBO/GLAAM state as well as solar activity. That winter also has a NAO that went slightly positive as the winter went on. This also happened to be another basin wide strong LA Nina winter.

Weak matches, or my secondary analogs are 1950-1951 and 2007-2008. With the winter of 2007-2008 we saw another strong basin wide La Nina with low solar activity and a slightly positive NAO/AO state. While the state of the AAM matches up fairly well the QBO was in a pretty strong easterly phase. However, SST configuration in the Pacific and Atlantic seemed like a good match for now as well. With 1950-1951 we also saw a strong La Nina winter, although it more more of a west-based Nina than a basin wide one. During the winter we saw a gradual increase in the state of the NAO/AO, however, again we saw a more easterly phase of the QBO compared to what the trend is right now. Solar activity was also more active this winter, however, this winter could begin to get more active as well. While these years aren't great matches overall they seemed to keep popping up when reviewing some things so I threw them in as secondaries.

With that said here are temp/precip outlooks for the upcoming winter:

As for snowfall in the Northeast goes I think it could be a big year snowfall wise for Northern New England but as you head southward there is a sharp cutoff in totals and with the exception of Northern New England snowfall should be below-average for the most part.

The good news is this will probably be wrong.

Anyways I don't want to mumble on much more, away with the criticism, don't hold back and if anyone has any suggestions on how to handle things when looking at things for long range forecasting please add them.