The Extract and Post processes handle the retrieval and distribution of forecast data. The Extract process supplies the input data needed by model alternatives during a forecast compute, and the Post process distributes the forecast results after the compute is complete.

Extracts

An extract is the process of retrieving data from sources such as a database, an HEC-DSS file, Cumulus, or the CWMS Data API (CDA), and mapping that data to the required input records of a model alternative. The extracted data is copied into a centralized HEC-DSS file called forecast.dss, which is then used as the source of input data during the forecast compute process.

Extract Groups

Extract groups define both the type and source of data to be copied during the extract process. Extract groups can be created for the following data sources:

  • Local HEC-DSS time series file
  • Remote HEC-DSS time series file
  • Local HEC-DSS gridded data file
  • Remote HEC-DSS gridded data file
  • A database
  • CWMS Data API (CDA)
  • Cumulus

Cumulus is a USACE only resource. Access requires a CorpsNet or VPN connection and CAC authentication.

Each extract group can only contain one data type and one data source. Some examples include:

  • time series data from CDA
  • time series data from a database
  • gridded data from Cumulus
  • gridded data from a local HEC-DSS file

Types of Data

HEC-RTS supports the use of both time series and gridded data.

Time Series Data

Time series data can be extracted from a HEC-DSS files, a database, or CDA. 

Examples of time series data include:

  • Observed stage and flow from watershed gages

  • Observed reservoir outflow from USACE projects

  • Forecasted river stages from the National Weather Service

Gridded Data

Gridded data can be extracted from HEC-DSS files or from Cumulus. 

Examples of gridded data include:

  • observed and forecasted precipitation
  • observed and forecasted temperature

Posts

A post refers to the process of saving data from the forecast.dss file to another HEC-DSS file, a database, or CDA. A post selects an output time series from the forecast.dss file and shares that information to an external data location. Computed/simulated output can be stored as results to be viewed or used in future forecasts. HEC-RTS supports the posting of gridded data and time series data.

Currently, you can only post data to a local instance of CDA.

Post Groups

Post groups are used to copy model output data from the forecast.dss file to a designated destination. Supported destination types include:

  • A local HEC-DSS file
  • A remote HEC-DSS file on a CWMS server
  • A Database
  • An instance of CDA

Post groups can only contain one type of data and one destination. Some examples include:

  • time series data to a database
  • gridded data to a local HEC-DSS file
  • time series data to CDA