Owls are migrating now, but finding owls during migration is FAR more difficult, in my experience, than finding them once they are established on their wintering grounds. The reason is simple - migrating owls only spend a day or two in each location, and there are not necessarily favored stopover roost trees along their path that one can learn about and revisit with high hopes each year. In contrast, wintering owls find favored roosting spots and stick to them. Some species (notably Long-eared and Saw-whet) will sit on exactly the same branch every day for two months or more!
One effect of the sit-in-the-same-tree phenomenon is there is a large build-up of pellets and “whitewash,” i.e. owl droppings, under the roost tree, making it much easier to find.
So how do you find owls during migration? By being extremely alert. Look for whitewash, even a small splash of it, and carefully check the trees above if you find any. Even better is finding a single owl pellet - all birds leave whitewash behind, and telling the splash of a Sharp-shinned Hawk from that of a Long-eared Owl is a task beyond my skill, anyway. But Long-eareds and Saw-whets cast well formed, cohesive pellets. Other birds, like hawks and gulls, sometimes cast pellets, but these are usually irregularly shaped.
Owls prefer conifer trees for roosting, with Eastern Redcedar being a particular favorite. But they’ll use what’s available, including other conifers, hollies, and deciduous trees, too.
Another trick for finding migrant owls is to pay very close attention to signs of mobbing behavior from chickadees, titmice, and nuthatches. I’ve found jays to be completely unreliable - they’ll fuss and scold just because they feel like it, and literally hundreds of times I’ve tried to track down the source of jay angst and come up empty.
But mind those little parids in particular. Twice I’ve found October Long-eared Owls in the woods at Brigantine NWR, thanks to scolding chickadees, and I’ve found a number of one-day wonder Saw-whets this way, too.
If you do find a roosting owl, be especially respectful of its space and avoid the natural tendency to get “just a little closer” for a better look. Migrant owls are readily flushable, and once flushed are forced to expend energy unnecessarily and may be exposed to predators, including hawks and other owls.