The week so far here has seen the Austin area troubled by major storms, thunder, lightning and considerable localised flooding.
Thursday night saw a continuation of that and with a major electrical storm brewing the corner workers were withdrawn (as per local statute) before the session was due to start.
Action finally got underway after an hours delay with rain still falling heavily, all drivers required to get in a full three flying laps in darkness.
Davide Rigon though was in trouble in the #71 AF Corse Ferrari, the car off the circuit between T17 and T18 with the initial local yellows soon followed by a red flag.
At that point, with times fairly irrelevant for the conditions most cars had completed at least some running but there was work to do for everyone when the session went back to green with 59 minutes remaining, the rain by now having eased off.
The Ferrari was recovered to the pits and would later rejoin in just enough time for the drivers to complete their required laps.
As the rain eased the times tumbled, the Toyotas to the fore for much of the latter part of the session with the Porches doing likewise in LMGTE Pro.
At the flag it was Tom Kristensen briefly topping the times in the #1 Audi, into the 2:02s but then Ant Davidson blitzed that mark – 2:01.333 for the #8 Toyota man.
KCMG topped the LMP2 times with the #47 Oreca posting a 2:17.000, the top three in class separated by less than a tenth (KCMG from ESM and G-Drive) but the Championship leading #27 SMP Racing car failing to complete the required night laps.
Gimmi Bruni split the two factory Porsches at the end, Fred Mako topping the GTE Pro times with a 2:17.588 as Richie Stanaway headed an Aston Martin 1, 2 in GTE Am aboard the #95 ‘Dane Train’ 2:24.111