I agree that the second part of the message gives out that you think negatively of him.

Also, it sounds like a demand: as if to say "You need to respond to me and if you don't for whatever reason you are ghosting me and being cruel and immature."

With regard to the request about the terrible weather: my sons would roll their eyes at this. I don't know if they would actually get angry, but they would take it as mom saying "Be careful" and react negatively to the implication that at their adult age they need to be reminded to be careful. I myself reacted the same way when my mother told me to be careful.

Perhaps this isn't something personal but rather is a standard type of mother-adult son dynamic? Idk but like I said, our sons would not welcome such a well-intentioned message from their mother, especially if they felt that their mother was saying that they needed to respond.

My own perspective as a dad fwiw is that no news is good news, we would hear soon enough if something bad had happened.

If I could suggest an alternative, something to consider I think would be a message along the lines of "Thinking of you". No request, just an expression of care and love.