A number of government agencies around the world provide ionospheric predictions, such as vertical foF2 or oblique path useable frequency range advice. Examples include IPS, SWPC and DIAS. Typically, the major customers of these agencies are in aviation and maritime (for HF comms) and defence (for comms and radar).
Are these kinds of services used by amateur radio operators? If so, how useful are they (compared with having to operate without any such advice?).