The ASCE7 2022 and TIA 222-I have made significant changes recently to the treatment of topographic speedup in the case of a range of hills or ridges. Previous versions of the codes effectively ignored the speed up for non-isolated hills or ridges. The TIA 222-I has implemented the rolling terrain option to deal with this case, whereas the ASCE7 2022 has opted to drop the non-isolated hill designation so that all hills are treated in a similar fashion for the purpose of the speed up calculation.
These changes have implications for design of new towers, but also for evaluating required changes to loading of existing towers. The issues are addressed in the following paper: Wind Loads on Towers in USA.
The ECCC site specific calculation for the S37 code has also changed in the past two years, although the users of the service are not informed about such changes. Because the report provided by ECCC provides no clarity on how the site is characterized, the user is not in a position to determine whether the correct site is being identified and how it is treated. I have seen erroneous descriptions of sites in a number of reports which the user is not in a position to identify from the report provided.
I have prepared a paper which discusses this problem in detail which you can download at the following link. Wind Loads on Towers in Canada