Are you using ArcMap 10.8 to visualize your daily precipitation data? If so, be aware of a visual artifact that may appear on your map: the line of No-Data running down the Greenwich Meridian. Depending on the colormap you select, the line can be grey or pink colored.
This visual artifact is most likely a bug in the ArcMap software. It can be confusing and misleading, as it may suggest that there is no data available in the affected area, when in fact there is.
To avoid this problem, we recommend using alternative software tools for visualizing your daily precipitation data. Some good options include Ncview, Panoply, or Python. These tools are open-source and free to use, and they are widely used in the scientific community for working with climate data.