Satellite images are used differently in the middle and high latitudes when it comes to icing. Three factors are of concern: space resolution, time resolution, and the availability of daylight.

The space resolution of MSG is fairly good in the middle latitudes, and there's daylight throughout the year. On the other hand, AVHRR images come only a couple of times a day, and thus are of limited importance.

In high latitudes the space resolution of Seviri images is poorer, and they do not reach the northernmost areas at all. AVHRR images are available around 14 times a day, plentiful enough to be useful. Daylight is sparse in winter, so the images used are usually the infrared ones.

Note: satellite images show the highest clouds, and if they are thick, these clouds can obscure lower clouds.