Long Range Model Forecast Interpretation through January 1st

This is my latest interpretation of the ECMWF model weekly long range.

I am going for a different approach on this starting today. Recently, I have been basically been showing you what the model has specifically forecasted on its map panels for temperature and precipitation anomalies.

However, I have noticed that the model's temperature and precipitation forecasts on many occasions do not fit the overall projected jet stream pattern for that given week. Next week it shows above normal temps over western Canada, and I know with the NW flow that will not be the case. Yes, it will warm up late in the week, but not enough to wipe out the very cold anomalies the first half of the week.

They also seem to continuously focus their strongest anomalies based on water temperatures off the Pacific and over Hudson Bay, which is mostly correct, but I think it is negatively affecting the rest of the temperature and precipitation forecast.

Clearly, the models long range forecast for the northern hemispheric jet stream (mean steering winds position) will almost always be more accurate than its temperature and certainly its precipitation anomaly forecast.

Precipitation total forecasts are one of the worst performers in short range models by the way.

Basically, what I am saying is that if you have a pretty good idea of what the upper level steering pattern will be, you can also have a pretty good idea of where it will be cold vs. warm and wet vs. dry.

So, for the time being, I am going to base these maps on the ECMWF's projected 500 mb height anomaly pattern and from that I will come up with the temperature and precipitation outlooks. We will see how it goes.

Actually, a couple years ago I was doing it this way before we had access to the newer ECMWF precipitation anomaly maps.

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