I use the aspiration reward weather machine for that purpose -- I like to keep some continuity in the time line. It's good for up to five uses. I was told you need to be in the gold or platinum to avoid bad results (like fireballs from the heavens), but I can't attest to that as I've (coincidentally) only ever used it with gold/platinum Sims.
I may have to try that...
Is there any post anywhere that has the weather machine's likelihood for failure, and/or failure outcome(s)?
I've been sending green (I *think* they were green, never really paid much attention) Sims to use it, with no adverse affect. May just be luck, with the random thing.