Winter Weather Predictions: El Nino Status
I thought it might be a good idea to take a look at the state of El Nino as of 2 days ago and see where things are going. Prior El-Nino posts spoke of water temperature action and attempting to see what this all means. Winter weather Predictions all have El Nino taking on a big part of the equation. The map above is the current water temperature anomalies (how much above or below norma) across the globe. A few things that I have noticed. Firstly is that the extent and intensity of the El Nino pattern that extends from the coast of South America and across the Pacific seems to have increased in intensity somewhat. Also the the watter temperatures across the northern Pacific reamin above normal however the departure from normal sees to be smaller than a month ago. A few pockets of below normal temps have developed in the North Central Pacific. This is an area we will have to watch since the warmer waters of the North and Northeast Pacific played a big role in the cold of the last 2 winters. A cooling of those waters to below normal would be an argument against a colder than normal winter.
Another interesting thing that has happened is the cold pool in the North Atlantci seems to have migrated west southwestward over the last month. Im not sure what the implication of that cold pool of water means. Water temperatures south of 35 degrees north in the Atlantic remain above normal but not as above normal as last month. The gulf stream off the northeast coast of the US remains strongly above normal which is interesting though again what this means in the longer term I’m not sure. We are still waiting for the North Atlantic Oscillation/Atlantic Oscillation to go negative again as it has been form much of the summer and early fall. This is also going to be critical to the winter outcome. One of the things I did notice is that looking at years with strong negative NAO’s during the winter (2009-10, 2010-2011) that cold pool winds up a little further south and west and waters warm to above normal just south of Greenland. Perhaps the migration of that cold pool could be a sign that the NAO is going to kick into gear at some point in the next few months. This is something we will need to watch carefully.
Now take a look at the El Nino on November 11th of 1997. Notice how much different that el nino is compared to this one. The Atlantic is completely different. The Northern Pacific is completely different. The vast majority of both oceans right now is showing near or above normal temperatures (except for the noted exceptions)!
It has been my contention that while the El Nino is formidable in size and scope, it is different from prior el ninos as is the profiles of the rest of the oceans in the northern hemisphere. I looked at the 2011-2012 el nino and one thing to note is that El Nino began in the fall and increased throughout the winter of 2012. That el nino was much smaller in scope. Check the water temperature map from November of 2011.
The El nino at this point was just beginning. Where the el nino is and the direction it is going is just as important as the extent of the el nino. This is why the decline of the intensity of this el nino is critical to how the winter in the United States takes shape.
At this point I think we pretty much know what is going on and none of this is any secret. Winter forecasts are on the table by most forecasters though I am anxiously awaiting the forecast from WxRisk which should be out any day. I am going to now being to shift my attention away from some of the longer term indictators and start to focus on the day to day changes and the short to medium range period. Watch to see how the upper air changes between now and mid December. I think the first important thing that has to change is the upper air pattern across Northern Alaska back to Siberia where the polar vortex has been parked. We need to see signs of that breaking down and shifting back to Canada. There is also no cross polar flow of any kind and that has to change as well so we can see air from Northern Canada transported into the east. We also need to see the dry weather pattern in the east change. Certainly seeing 2 weather events how ever minor 3 days apart is a lot more active than we have seen in the past 5 months. The consensus is for a stormy winter regardless of the cold. That part of the short and mid range pattern has not really shown any signs of changing. Here we are in mid Novemeber with lots to ponder over…which is where we were at this time last winter…and the winter before that…and so on and so on.