I can't decode a TAF well enough to post it on here, but looking at this we can see that it will be very windy but not cold enough to snow with a freezing level of 500 meters.
This TAF which comes decoded automatically on this site:
METAR TAF : Heathrow Airport, London-Heathrow England and says 2500 meters visibility with high crosswinds so yes delays and cancellations inevitable, but nothing too crazy hopefully. Flow restrictions at LHR due to visibility and wind?
