Why on Earth would the host at the restaurant seat two customers out on the deck when they're having a blizzard? My Sim got a call from his mother-in-law requesting that they go out to eat. Never mind...
lol that's funny. Almost the same thing happened to me, but it was a thunderstorm.
My couple were very tense dining outside on the patio. I figured it would be okay since the tables outside had umbrellas, but I saw a icon above their heads with a thunderbolt as they stood up quickly. Another guest sitting at another outdoor table got stuck by lightening. They didn't die, but were very crisp. After all that stress I thought it best to cancel the dinner and let them go home.