Hmmm, lesson learned.
However...
1. I knew Cosford airshow is on tomorrow but missed todays notam
2. I missed todays notam because it is shown by Notamplot as "aerodrome nav warning" not an "en-route"
3 I had not previously realised that aerodrome warnings are displayed only under a second tab in Notamplot.
I would presume that you obtained a 'proper' briefing'...yes?
If so, it left a lot to be desired.
As Lockheed-Martin has taken over the FSS briefing responsibilities in the USA, 'problems' have developed.
However, these are on the mend..
Result?
Check carefully, an some NOTAMS are not where they had previously thought to have been.
Lockheed-Martin has got the message...ship up...or ship out.
The FAA means business.
In the UK, relevant NOTAM issueance is...well...obtuse.