The image (courtesy tropicaltidbits.com) above shows the upper level piece of energy that will finally reach the west coast of the United states on Tuesday evening (blue colors over Washington state show the shortwave energy in the upper levels of the atmosphere). This piece of energy will ride the jet stream into the mid-south before becoming a coastal storm.
Bottom Line: Until this short-wave reaches land, there remains some uncertainty in the forecast models due to the inaccuracy of exactly how the Friday-Saturday storm system will evolve. This is because there are more input data locations over land than water, so once the system reaches land we have better input data. Remember computer science? Garbage in- Garbage out. You don’t want bad data in — otherwise the solution in the future may be inaccurate.
The good news this morning is that the ensembles continue to be in relative agreement of a coastal storm forming on the Mid-Atlantic coastline but the devil is always in the details.
Let’s take a look at the other Ensemble models:
Global Ensemble Forecast System (GEFS) – Noon Saturday
European Ensemble – Saturday Evening
Canadian Ensemble – Noon Saturday
Stay Tuned for updates!