I remember when the Weather Channel was actually good and they did the "look ahead".. it was at 50 past the hour and it was obviously snow weenie stuff..
They would start out every one with the ten day progression of the jet stream..
without knowing any of this above, after a while I could recognize what the jet stream would look like when there would be a corresponding snow storm in our area..
I realize now that they were showing the jet stream because it was how they use pattern recognition to sniff out snow storms in the long range.. its the same thing we do now.. we just have a lot of fancy acronyms that end in O.