... uncertainty for Philippe is much higher than it would appear as the National Hurricane Center explains...
Increasing shear is forecast to otherwise counteract a conducive environment, leading to little net change with Philippe during the next couple of days. Afterwards, models are in quite poor agreement on if the shear continues to rise to strong levels, which causes dissipation like the ECMWF, or if it becomes more manageable to allow for further intensification, similar to the GFS's hurricane forecast at day 5. There are no obvious clues to the correct solution, and this is probably a very difficult forecast due to the feedback of Philippe's track affecting intensity, in addition to the inherent challenges of moderate shear cases. Thus, little change was made to the intensity forecast, which lies near the overall model and corrected-consensus aids. The storm appears to be moving west-northwestward or 290/10 kt. The subtropical ridge to the north of Philippe is forecast to gradually weaken and slide eastward in a day or two, allowing the tropical storm to move more west-northwestward and northwestward by the middle of the week. Uncertainty is large after that point, with the track very likely also dependent on the intensity and vortex depth, and the GFS and ECMWF models are on the opposite sides of the guidance envelope. The long-range guidance has shifted a bit westward on this cycle, and the new forecast follows that trend. However, this forecast should be considered low-confidence in both track and intensity.
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