There will be a pitch inspection at Hartley Wintney at 9am tomorrow morning.
The timing should be early enough so that Hereford supporters will not have started their journey to the game if it is called off.
Updated 3.45: BN has been told some supporters are leaving on trains before 8am.
Currently the pitch is playable but rain is forecast overnight.
Meanwhile tickets for the game can still be purchased until 4pm either at Edgar Street or online.