Frank may I ask a few questions.(1)What effect will the ULL have on the ridge to the N is it buffering it more N.Then allowing or raising the ceiling allowing more head room for Isabel.(2)They both appear to be moving about the same speed.Is the ULL possibly clearing a pathway.A vacuum path of least resistence.(3)If Isabel did gain speed on the ULL could it be sling shoted over the ULL.I realize some serious compression of Isabel would take place.I just never forgot how Claudette did that ULL .The SOI well taken and understood very plausible explanation.