Skies remained a little threatening as Moto2™ headed out on track for their first session of the weekend, but conditions were dry in the initial stages. Early leaders in the session proved to be home hero Sam Lowes (Federal Oil Gresini Moto2), Tom Luthi (Garage Plus Interwetten) and Alex Marquez (Estrella Galicia 0,0 Marc VDS), before the red and white flag came out to announce drops of rain on track - just as Forward Racing's Lorenzo Baldassari took a tumble. Lowes was top at the time, with Luthi and Marquez just behind.
The majority of the intermediate class then headed back into the pits as spots of rain began, with conditions then worsening as the rain began in earnest.
Brno winner Jonas Folger was fourth fastest on the timesheets ahead of the shower interruption, ahead of Takaaki Nakagami (Idemitsu Honda Team Asia) and reigning champion Johann Zarco (Ajo Motorsport). Sandro Cortese (Dynavolt Intact GP) was in P7, ahead of Hafizh Syahrin (Petronas Raceline Malaysia), Miguel Oliveira (Leopard Racing) and Julian Simon (QMMF Racing Team), who completed the top ten.
Zarco was one of the first back out, but the lap times didn't improve with the rain still coming down.
Title contender Alex Rins (Paginas Amarillas HP40), after breaking his collarbone in a training accident before the British GP, was only 24th on the time sheets with a slow start, but will be looking to progress slowly towards the field as he rides through the pain barrier.
The Moto2™ grid will be hoping for a drier FP2, ahead of Saturday and qualifying.