|1200 UTC 2 Sep – 1200 UTC 4 Sep 2014 IR satellite imagery with GFS analyzed precipitable water contours every 5 mm|
|0600 UTC 4 Sep GFS forecast valid 2100 UTC 8 Sep 2014. Source: Wundermap.|
In contrast, the upper-level trough in the EC remains a bit further north and the flow over the eastern Pacific is weaker. As a result, Norbert moves more slowly and remains well to the south on Monday.
|0000 UTC 4 Sep ECMWF forecast valid 2100 UTC 8 Sep 2014. Source: Wundermap.|
These are the sorts of divergent forecasts that one can get during weak flow situations with interactions between tropical and extratropical systems. Time will tell if this will be another victory for the ECMWF, an upset by the GFS, or some sort of draw (i.e., Mother Nature splits the difference). For predictions like this, forecaster's often need a friend.