Latest weather model projections indicate fairly wet weather up to and including this weekend, with a warmer, drier couple of days following, but by mid-next week a return to cooler, showery weather, with longer spells of rain in between. But by National day drier again.
A long way off in weather terms, but seems to indicate a mixture of dry and wetter weather. On that basis i’d predict similar ground conditions to whatever course officials are calling today.
aside from early bets (and i’ve had a few) if you’re worried about the ground and what certain horses will do on it, wait until the Friday eve or the actual morning of the National.