Some Interesting Implications...

After doing some more research.. There hasn't been much correlation between this year's ENSO phase and other years. I've been looking for years that correlated well with an ENSO neutral event after a "double dip" La Nina. So far, 1977-1978, and 2009-2010 come up.. There haven't been any other "double dippers" (I have not included the years from 1998-2001 because that wasn't really a double dip La Nina, more of a continuous one that got us going in the so far downward trend in the PDO) than these.. And I want to opt out and not include 2009-2010 because of the strength of the El Nino (at this point it isn't likely we see a strong El Nino). In fact, most of the atmospheric signals indicate that this El Nino won't even survive for the beginning of the winter.  An ENSO neutral winter occurring after a double dip La Nina has not occurred in the history of record keeping of the ENSO phase. At this point, if weather patterns were to be followed, then I would predict a moderate or strong El Nino by winter. If I were to follow other signals, then an neutral ENSO winter would be more likely. I have made a map that shows the average temperature anomaly of all the ENSO neutral winters that are on record.

This clearly indicates that most ENSO neutral winters featured below normal temperatures, especially across the Northern Plains.

At this point, I really don't want to say what this winter will bring. With its unique weather patterns and variables, I cannot accurately use analogues to predict the winter temperature, snowfall, or precipitation. At this point, I'm going to lean on the side of caution. Quite a bit of data would suggest that a colder than normal winter is coming for the U.S. Some data would suggest that we will receive a warmer winter. In the history records, there have been two years that came out of a true double dip La Nina into an ENSO neutral or weak El Nino year, and one year that came out of an elongated La Nina. The two years that became a weak El Nino after the "double dip" La Nina were extremely cold years. The year that became a weak La Nina winter after the elongated La Nina, featured warmer temperatures across the East and cooler conditions in the West. At this point, the weather patterns are most similar to that of the first set of years, which occurred after a "double dip" La Nina. This would indicate that this upcoming winter could feature the same. More data will have to come up to prove this, but it is a very possible scenario. The only reason that I won't confidently project the idea of a very cold winter is because of what happened last year. For a few weeks I will wait and see what will happen.

For some entertainment, here is a map providing the average temperature anomaly across the United States from the winters of 1977-1978 and 1976-1977..

Temperatures during those two winters averaged nearly 10 degrees below normal.. According to archives and other records, the two winters featured extreme arctic cold, and several notable blizzards and snowstorms.

Longer Range Forecast...

Some interesting developments have occurred in the longer range forecasts of the ECMWF and GFS. One of the main things that I look for in the models longer range forecast hours is the general upper level flow patterns. In the 240 hour timeframe, the ECMWF is forecasting the development of a large upper level trough as the ridge in the Gulf of Alaska restrengthens (suggesting to me that the Polar vortex will remain weaker through the long-range). This upper level trough will show up as a slightly negative PNA teleconnection in the forecasts. With this kind of a jet stream configuration, strong southwesterly flow in the upper atmosphere is likely over our area. This is a pattern favorable for storm systems to transverse the Midwest and Central Plains. In the longer-range, I would anticipate near normal precipitation, due to the fact that most of these storm systems will be diverted to the north and west of the area. So far, this is an atmospheric set up very similar to the fall of 2010. The rather warm fall of 2010 eventually gave way to the very stormy and cold winter of 2010-2011. One forecast doesn't mean anything, but if this is consistent, I would bet on seeing a winter across the United States that will be very similar to the winters of 2009-2010 and 2010-2011. In the meantime, what it means for us is that we will likely continue with a warmer than normal, with a possible slight re-strengthening of the current moderate drought conditions.

El Nino and Tomorrow's Forecast

To begin today's forecast and outlook, I will begin with another update regarding the long range forecast. The El Nino has severely weakened over the past few days and weeks. Now, while I do refer to this event as an El Nino, it is not officially an El Nino. To be considered a true ENSO event, the Sea surface temperatures relative to normal (on either side of the spectrum) across the Equatorial Pacific need to be at least 0.5 for an El Nino and -0.5 for La Nina. This condition needs to be true for at least three months. In this year's case, neither has happened. SST anomalies have not been consistently above 0.5 degrees Celsius, and they have not persisted for three months. In fact, in the latest analysis of the El Nino, most of the remaining warmer waters have faded and shifted westward, causing an extreme weakening of the El Nino. This could be really good news for anybody who loves a good winter in our area. Using climateology, "neutral" winters  usually give us the best chance for heavy snowfall events across the area. Hopefully, this is true, as last year was too warm to support any "real" snowstorms.
    
For tomorrow's forecast, I expect clouds to build into the region ahead of a shortwave. I expect a few showers and even a thunderstorm in the afternoon hours. Yet another small "storm system" will move south out of Canada, sideswipe the area with some rain on Wednesday. A short period of cooler temperatures will come to the area after the passage of the cold front, with highs dropping into the middle 60's on Thursday. For most of the week, I expect temperatures to remain right near 70. By the beginning of next week, signs are pointing to cooler weather across the United States, and a stormier pattern looks to resume across the Northern Plains.