The Current Icing Product (CIP) and the Forecast Icing Product (FIP) that freely available on the Aviation Weather Center website are both utilized in the EZWxBrief progressive web app. Shown below is the icing depiction in the EZRoute Profile. So let's take a look at the differences between CIP and FIP.
Both CIP and FIP consist of three products, namely, Probability, Severity and Supercooled Large Drop (SLD) icing. SLD is a "potential" field whereas the icing probability field for both CIP and FIP is a calibrated probability. You can read more about the importance of using a calibrated probability here.
First of all, it is important to understand that CIP is an analysis. In other words, it's a glimpse of the recent past. Therefore, CIP is not intended to tell you about the future. That’s the job of FIP. CIP is produced on a grid that roughly matches the Rapid Refresh model output. Each grid box is roughly 13 km or about 8 miles from side to side. When CIP runs, it produces output every thousand feet from the surface to FL300.