Speculation: winds from Bonnie obliterated most of the thin sheen throughout the area; but since then, sheen has had time to “reassemble” into observable layers that noticeably affect the sunglint on MODIS images, and the backscatter on radar, but may not look like much to folks out in the Gulf on vessels or in low-flying aircraft. That’s our theory at this point.
Shake a bottle of oil and vinegar salad dressing and sure enough, very little oil will be seen at the top. That is what happened during Bonnie. But let that same salad dressing sit still for a while and the oil eventually separates and floats back to the top. That is what is happening now!