One thing about being away and fishing for a few days. It clears your head however it may clear it a little too much as now I am trying to get up to speed on what may happen down the road. One thing I did notice about forecast models today is that they are quite different in what the do over the next 10 days. I will simply say that whenever we go into a negative phase for the North Atlantic Oscillation or the Atlantic Oscillation, models tend to become very volatile. It will have deep troughs on one run and strong ridges on the next run with apparently no rhyme or reason. Let us first look at the broad scale. The models have been forecasting that these 2 long range indicators to go negative from mid month on and have been doing so all week. There is no real change to this outlook. The negative trend would mean a colder and potentially stormier pattern. By colder I mean by November standards and not by mid winter standards. I don’t think one should jump to any conclusions that this means early snow or winter like cold. we are just in the second week of November. What we can say is that we may be transitioning over to a more active weather pattern with the active el nino combining with a “blockier” look to the atmosphere.
The charts above measure the index value. Above zero means that conditions in the east are pretty much the way they have been..very warm and inactive. We are currently just coming off a peak in both indexes. Below zero increased blocking in the Atlantic and a displacement of colder air from Canada southward (relatively speaking). Today’s forecast models show no change in this forecast.
Now does this mean it will be instantly cold and stormy? NO IT DOESN’T frankly in terms of absolute specifics it could mean a host of things. Yes it could mean colder than normal but if these indexes don’t become strongly negative, the blocking could be weak. Another issue is if colder air is going to be displaced southward, so far the air in Canada is not all that cold. Temperatures in Canada have been running above normal. We have not had any sort of cross polar flow at all in the last month to 6 weeks except for 2 short periods.
Now if you really want to see confusion in weather forecast models, take a look at the gfs and the European at day 10.
Look at these weather forecast models and you would swear you were in 2 different worlds. The European has a big high in Southeast Canada while the GFS has some sort of snowstorm and a deep low in New England for the exact same time frame!!! This is due to how to models seem to handle upstream energy with the GFS going nuts with it while the European instead evolves differently beginning at day 7 which puts the east into another strong upper high position!
How do we resolve all this. Well the safe thing to do right now is punt. I went back and looked at all the runs while I was not catching fish this weekend and came to the conclusion that it would be foolish to even speculate what happens beyond this week. I can say that it does seem that we are going to start a more active volatile period where forecast models will be shifting 180 degrees on every run. This is going to keep forecasters on their toes for sure.
One final note to snow lovers. This is not even mid November. You need to be reminded that to come to any conclusions due to the kind of weather we are experiencing now is a pretty foolish way of forecasting. In fact I would advise young forecasters that this might be a good opportunity to empty your minds of all your preconceived notions of what is going to happen over the next number of days weeks and months and just simply watch how this all plays out in the coming weeks. I guarantee you there will be several valuable lessons you may learn about how weather works.