The North American Ensemble Forecast System (NAEFS, what a quality acronym) is a fun toy to play with... uses large ensemble forecasts to give a good sense what the range of possible outcomes is, and the EPSgrams that can be generated for cities are a pretty clear way to look at the forecast uncertainty. See this
example
, which can be generated
here
for a variety of cities in Canada, the US and Mexico.
This
is a fun way to look at many possible future versions of the atmosphere... My read is the ridge breaks down next week, and odds are good it stays broken down for a bit, though only a couple ensemble members bring a strong system across by the end of the forecast period. It's interesting to walk the original forecast time backwards and see how the probabilities shift... the uncertainty in the uncertainty is kind of meta and hard to wrap your mind around, but seeing how the error bars shimmy from forecast to forecast gives you a sense of whether the ensemble really has a handle on what's going on.
