I have found that if you delete the metoffice cookie after use, subsequently the site will not load all of the available information, and will only show part of the site and helpfiles. Also, curiously, it will load OK if you run IE with protected mode disabled(not advisable).
To reset IE so that the metoffice will load properly, go to Tools> internet options> general tab> Delete browsing history and set as follows:
UNTICK Preserve Favourites website data
TICK Temp internet sites and website files
TICK Cookies and website data
TICK ActiveX filtering and tracking protection data
Set other options as you require.
Click delete button.
And in future, do not delete the metoffice cookie; you should find the site then works OK.