but BHX at the time was 1500mtr, so unlikely a weather issue.
It's been rather fortunate at times. Even earlier this morning, the met vis. at BHX was giving 100m for quite some time but the RVR was 1,000m or greater. That said, there was a case over the weekend where the met vis. was 9km but the RVR about 300m!
So, 3 diversions to MAN. Maybe it's purely coincidental, but I reckon our fog probably was a key factor for the notam even though we are Cat3 along with most jet aircraft and crew these days. Maybe we'll never know the reason(s) but it will be interesting to see the response if there's another similar fog situation.