This could well be the flow chart that the Met Office use to decide whether to issue a yellow warning for strong winds. I’m not going to bother excusing them because they’ve adopted to use the impact warnings method instead of one that’s based on thresholds alone. Here are the plotted winds for Lerwick for the last 36 hours. You’ll notice that at 10 UTC this morning there was a gust to 60 knots (69 mph) there, but according to the Met Office, none of this merits a yellow warning for strong winds and their warnings board remains clear.
It’s not just the northern Isles that are seeing gales today from low Fabio but much of the west coast of Norway too as you can see.