RaInDROP Updates

April 7, 2026

Release of RaInDROP Version two (V2). This version adds sub-hourly rainfall data and corrects for precipitation depth errors noted for the Southern Mountains in RaInDROP V1. Specifically, the NOAA Atlas 14 precipitation depth dataset we originally used merged different Atlas 14 volumes.

Unbeknownst to us, this merging (with a smoothing technique applied) created problems at the boundary between NC and Georgia. Additionally, RaInDROP V2 uses the Annual Maximum Series (AMS) and is now more consistent with the scale-factor methodology used to derive future rainfall depths. Note that RaInDROP V1 used the Partial Duration Series (PDS) for scaling, and hence, small differences may be noted for other locations within NC, but these differences are insignificant relative to future uncertainties. Precipitation depth projections were also created for all HUC-10 basins that intersect NC to assist with watershed-related issues identified by stakeholders.

To find out more details about RaInDROP V2, such as the error correction for the Southern Mountains, please read the supplemental document.

December 5, 2025

Problem identified
There is a current issue with the Atlas 14 values, resulting in incorrect precipitation depths and intensities for parts of the mountains in the southwestern part of NC, which is highlighted by the black box on the maps below.

We are working to provide a fix to this problem.  Please do not use precipitation depths or intensity values as highlighted in the figures below.  Thanks for your patience as we work to provide an update.