Sky signals come from a satellite 22,000 miles above the Earth's surface. The transmitter on the satellite is fairly low powered and the signal has to be spread across the UK and parts of Western Europe. That means that your dish has to be very carefully aligned to pick up the very weak signal which arrives where you live. The recent winds might have knocked the dish out of alignment. Alternatively, rain or snow might have found its way into the connections on the antenna. It's likely that you need to get an aerial fitter to take a look at your dish.
Chris