Only McLaren and Ferrari, who had Stoffel Vandoorne and F1 debutant Antonio Fuoco in their respective cars, were able to complete installation laps before track officials decided to red flag proceedings because of the amount of standing water on track.
Conditions mercifully improved enough for running to resume after lunch, and the extension will allow teams to make up for lost time in what is the final in-season test of the year, with all squads bar Marussia in attendance.
Formula1.com and our official Twitter channel, @F1, will bring you the latest news, images and reaction throughout the Spielberg test. Subscribers to the official F1 App can also get regular live updates on the latest testing times from Austria.
