i got some slight warping along the edges of the first couple of pieces of hardwood right by the front. I'm guessing some water seeped in under the door sweep that we didn't notice. this is select grade oak hardwood installed in the last year, stained a dark walnut brown and finished with 3 coats of water based varnish.

other then resanding them even, is there any other way to reflatten the edges?

First, make sure the door is not only water proofed, but that moist air cannot penetrate along the bottom edge.
It may flatten on its own as the reaches normal MC so at this moment, I recommend take a "wait ans see" attitude.

waterproofing it is definitely my first order of business.

really it might flatten back on it's own? i thought once wood warped or raised it stayed that way. i was wondering/hoping that there was some trick of the trade

Cupping is a sign the bottom of the board is wetter then the top of the board.
Wood being hygroscopic, it swells with added moisture and shrinks with a loss of moisture.

The bottom of the board has swelled and the top of the boards have not, thus leaving a cupped appearance. If the moisture in the bottom of the board dries out back to the same as the top, it will flatten back to the original state.

thanks for the info. i really thought that once wood had cupped it was permanent. the affected pieces must somehow have dried on the bottom because i was changing my door sweep and noticed the cupping had almost completely gone away... : )