Weather is like a Mag after a Safety Meeting
This is the best description yet on weather models and forecasting/predicting what's gonna happen next from Joel Gratz on Open Snow:
Quote:
The upcoming storms are hard to forecast
People often ask me what makes some storms easy to forecast and what makes storms harder to forecast.
The easier and more confident forecasts are when a well-defined system moves quickly. Think about a strong cold front that moves through with 3-4 hours of intense snow and then it’s gone. Models do a good job with these storms and the forecast is often consistent for days before the system arrives.
The harder and less confident forecasts are when a less well-defined system moves through more slowly and changes strength as it moves. This is what we have coming up with the next three storms, so expect the forecast to continue to change even right up to the storm’s arrival.
Putting all of this another way, if a train is moving down the tracks at 60 mph, it’s easy to forecast where that train will be in the next minute. Compare that to a person that leaves a bar late at night and slowly trudges down the street, wobbling a little bit as they walk. Where will this person be in the next minute? That’s a less confident forecast!