The pilot reported that he was landing the airplane in turbulent conditions with gusting wind. He stated that during the landing flare, the airplane encountered an updraft, followed immediately by a downdraft. The airplane subsequently impacted the runway and the nose landing gear collapsed, resulting in substantial damage to the engine firewall. The pilot reported there were no mechanical malfunctions or anomalies of the airplane that would have precluded normal operation. Review of archived weather information for the accident airport about the time of the accident revealed variable wind at 9 knots with gusts to 19 knots.