On 30 May 2023, NSSL was notified by Environment and Climate Change Canada (ECCC) that the radar scanning pattern used by all Canadian radars will be changing between 5 and 15 June 2023. ECCC will first deploy the change at three radar sites on 5 June 2023. Then, between 12 and 15 June 2023, the other 27 Canadian radars will switch to the new scanning pattern. This scanning pattern means that most elevation angles scanned by the Canadian radars will change. The six bottom-most elevation angles will also have new, extended ranges.

As radars are switched over to the new scanning patterns, they will disappear from the operational MRMS system and from the MRMS products displayed in NSSL MRMS Operational Product Viewer. NSSL is currently working on a patch to the MRMS system that will enable the decoding, processing, and display of the Canadian radars using the new scanning pattern. Once this patch is complete and has been tested, we will coordinate with the National Weather Service to implement the fix in the operational MRMS system. We will provide an update as we learn more about the implications of the scanning changes and have any more specifics to share about the scheduling of an MRMS patch.