"It depends on how good they are. Sorcerous spells depend heavily on the conditions under and targets on which they're cast. A very good sorcerer will be able to correct for multiple sudden disruptive factors at once, especially if all they're casting on is themselves and the disrupted place is one they otherwise know well, because they'll be very familiar with themselves and their turf. A middle-range sorcerer will have to spend time recalibrating to get anything significant done."