Why visibility suddenly to 1 hex?

[bdtj1815]

Interesting thread but I am having the reverse happen in Minsk44. Although the weather.dat for the 23rd is:

23 6 1944 0 100 0 0 0 2 2 0 (default unedited)

sometimes, I have been testing a new scenario many times, the visibility increases to three. This makes certain German units visible in the south and so triggers spotted Russian releases which should not occur until the 24th.

The only change I have made that might effect this is to edit the starting turn to 0400, ie a dawn turn.

Any help please.