White smoke is almost always moisture. I've seen a bad vacuum modulator on a transmission allow atf to get sucked into the engine and burn creating voluminous clouds of white smoke but there is no vacuum modulator or vacuum hoses on your trans. So that rules out atf.

If you had been starting the engine for just a few moments at a time, for several events, then a large amount of moisture could have built up in the exhaust system, then when you hit the pedal hard, all the exhaust heat vaporized the collected water vapor in the exhaust causing a cloud. I have seen it before. If that is not the case, then I would get the cooling system pressure checked to see if you have a head gasket problem. A pressure test will show a leak.

Check your oil level, see if it is rising or if there is a milky chocolate like foam on it.

DEWFPO
1998 S90 077,400 and 1995 964 154,100

P/S This is probably not your problem but there is actually another way to get this car to blow white smoke and it has happened to me twice. Our 98 S90 had a bad pressure sensor on the A/C system and on extremely hot days with the A/C on, the compressor would overpressurize the A/C system and the high pressure pop-off valve on the compressor would blow. The R134a coming out at 538 psi creates a white cloud (with no residue) and an associated 'jet engine type roar' coming from the engine compartment. Like I said, probably not your problem, but it does fit the description.