The crucial Group B contest had to be abandoned after 33 minutes on Tuesday night due to a severe hailstorm at the Turk Telecom Arena.
The remainder of the game is due to be restarted, as per tournament rules, at 1pm GMT.
But the weather forecast for Istanbul remains poor, with temperatures not expected to rise until the weekend.
That has put today's resumption of the game under threat, with UEFA officials nervously awaiting further updates.
The home side, managed by former Manchester City boss Roberto Mancini, must beat their Italian opponents to progress to the knockout stages of the competition behind group winners Real Madrid.
A draw would be good enough for Juventus to advance, as they are two points better off than Galatasaray in the group.
Coverage from Istanbul is due to get under way at 12:55pm today on Sky Sports 2 HD - weather permitting!