6 July 2023 – USACE Announces the Availability of the Antecedent Precipitation Tool, Version 2.0

HQUSACE Regulatory
Published July 6, 2023

USACE is announcing the availability of the Antecedent Precipitation Tool (APT), version 2.0.0. This new version of the APT contains additional functionalities (see list below), to include the incorporation of a newly developed gridded daily precipitation dataset from the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI).

  • Full integration of the NOAA U.S. Daily Gridded Precipitation Data (nClimGrid-Daily; https://www.ncei.noaa.gov/thredds/in_situ/nclimgrid-daily.html) and its associated station count data (https://www.ncei.noaa.gov/thredds/in_situ/nclimgrid-daily-auxiliary.html).
  • Updated user and technical guide to reflect incorporation of the nClimGrid-Daily data into the APT.
  • Addressed issue with batch processing that was limiting the use of appropriate station data during station-based APT analyses.
  • Addressed issue with sizing of station table in pdf outputs when using large numbers of stations in a station-based APT analysis.
  • Addressed issue with interpolation algorithm that fills data gaps in a station-based APT analysis.
  • Reconnected to new WebWIMP data service.

This new data- the U.S. Climate Gridded Dataset-Daily (nClimGrid-Daily) precipitation dataset- will be useful for instances in which there are not enough suitable weather stations to perform the APT analysis due to poor weather station coverage or instances in which multiple nearby weather stations are missing the same periods of precipitation. This dataset may also be useful when the primary station is further away from the observation point than the dimensions of the grid cell (e.g., if the primary station is 40 miles from the observation point).

Users of the APT version 1.0.23 should download the new APT version 2.0.0 because version 2.0.0 also provides fixes to several bugs in the traditional APT station-based analysis.

USACE is also announcing the release of a new user guide for APT 2.0.0, which serves as both a user guide and the technical documentation for the APT, including its inputs, outputs, analyses, common errors, and troubleshooting tips.

LINK TO APT (VERSION 2.0.0) USER GUIDE: https://erdc-library.erdc.dren.mil/jspui/bitstream/11681/47189/3/ERDC-TN%20WRAP-23-2.pdf
LINK TO DOWNLOAD APT (VERSION 2.0.0): https://github.com/erdc/Antecedent-Precipitation-Tool/releases/tag/v2.0.0

NOTE: Users should utilize the following steps to ensure successful download and use of the APT.

  1. Download the "Antecedent.Precipitation.Tool.7z" file from the link above.
  2. Extract the “Antecedent Precipitation Tool” folder from the 7z file. We recommend creating a stand-alone “APT” folder on your C: drive (e.g., C:\APT), and extracting the “Antecedent Precipitation Tool” folder into that folder on the C: drive.
  3. Run the file main_ex.exe within the “Antecedent Precipitation Tool” folder to begin the installation process. Running the executable will also create an Antecedent Precipitation Tool.lnk file on your Desktop that you can now use as a Desktop shortcut

The APT may be used to accelerate USACE decision-making time by automating and augmenting the requirement of the Regional Supplements to the Corps of Engineers Wetland Delineation Manual (Regional Supplements) when evaluating precipitation and other climatic variables associated with 1) difficult wetland situations (see Chapter 5 of the Regional Supplements) or 2) the assessment of certain wetland hydrology indicators (e.g., saturation or inundation visible on aerial imagery or dry-season water table). The APT also has utility in evaluating precipitation normalcy for site visits, when reviewing wetland determination data forms, or when collecting, observing, or evaluating streamflow duration information or data.

To report errors or issues with the APT, please email apt-report-issue@usace.army.mil.