I find that you can throw a topwater lure for bass at anytime, I caught three bass on my topwater this year in early february, but it was a small lake I was at. Sure the morning and the evening are the preferred times to throw a top water but don't hesitate to fool bass into striking a top water at anytime, when conditions get tough I always throw a topwater just for fun. Two techniques I reconmend are a topwater zara spook and a small floating rapala. With the zara spook you might need to use a bass rod but you reel the bait in and use the walk the dog technique to make it dance side to side. WIth the little floating rapala I throw it near lilly pads and stick ups and just give it a subtle twitch and then let it stop, this works great. I like Lake Ballinger, Lake Goodwin, Lake Samamish, and Lake Washington, good luck with your fly rod.