Storm Kathleen impact?

The thing with Scotrail is that the rail industry in Scotland is still heavily traumatised from one fatal accident and another very near miss accident, both in severe weather.
So everyone is playing very cautious and the rail industry is closing down as a precaution way in advance of when it would in England. But the lines are also electrified, so if the winds bring the overhead wires down then it's game over anyway.

The Glasgow to Troon bus is run by Citylink, not Scotrail. That will run, regardless.

If you get stuck in Troon then make your way to Ayr or Prestwick Airport for shelter for the night. There is also an hourly or better express bus service from Ayr to Glasgow. If you get stuck in Ardrossan get a citybus to Kilmarnock, then citybus Kilmarnock to Glasgow.

But if by Saturday evening CalMac are saying that services are full or cancelled on Sunday then stay in Glasgow., do not travel I would research hotel availability now for Ayr and Glasgow for Sunday night.

This is a developing situation.

Thank you so much - you are so thoughtful and generous with your time!

Weatherwise it has been a lot better here today, the heavy rain was there overnight has gone and it is a clear day. But there are still weather warnings on, I'd keep an eye on the apps mentioned above but also the weather from BBC Scotland and STV.

At least its a short crossing , I had a bouncy ride to Islay last summer.
Hope you get to set sail

So what has happened today is that the Lochranza and Ardrossan routes to Arran have been cancelled all day.

The Troon route ran the first two sailings, but the afternoon sailing is cancelled (due to high swells), as is most of the CalMac route network currently.

All Ardrossan sailings are now CANCELLED on Sunday, as are all Sunday morning sailings to Lochranza.

So my advice would be to book the first ferry (0835) out of Troon tomorrow (Sunday) morning on the CalMac website/app (and also a sailing back to Ardrossan on Tuesday).

Booking tonight assures you of a space.

I would also book tonight on the 0735 connecting bus from Glasgow Buchanan Bus Station to Troon Harbour, to be sure of seats.

Sunday looks promising for Troon on Sunday but if it all goes pear shaped tomorrow get a train back into Glasgow, or a later bus back to Buchanan.

The local bus from Troon Town to Ayr Bus Station on a Sunday is at 53 minutes past each hour (Bus 14 headed to Ayr Hospital) arriving Ayr at 38 minutes past each hour. The X77 back from Ayr to Glasgow leaves on each hour until 1700, then at 1740 and hourly to 2140.

Buy your Train ticket from Ardrossan Harbour to Glasgow when you get there on Tuesday morning.

UPDATE- Due to the forecast worsening the Sunday afternoon sailing from Troon is now cancelled. Only the morning and lunchtime sailings will run, on a sailing by sailing basis.

I see that the MV Alfred sailed from Troon on the morning sailing as scheduled.

And you had the rare sight of two vessels in Brodick as the Isle of Arran was on the relief berth sheltering from the storm, while you used the linkspan.

We made it! Seeing both vessels in harbor was a nice sight.
Much thanks for all of the sound advice and recommendations. I feel like we owe our success to you!