As described here, hydrologic forecasting is inherently interactive.
The initial design of NWSRFS recognized this, but was limited because computational requirements demanded that the forecast system run on a mainframe computer with little interactive capability.

The computational capabilities of scientific workstations have evolved so that the design features of the latest version of NWSRFS allows for interactive forecasting.



Software in the design
A LINUX-based fileserver (updating the original UNIX-based system) runs the NWSRFS OFS and creates a set of model conditions and time series.
Forecasters at networked scientific workstations may then initiate simultaneous IFP sessions on different sets of sub-basins.
Each IFP session: At the end of an IFP session, adjustments made for any of the sub-basins are transferred to the fileserver to be incorporated into further forecasting activities.

The IFP runs on a scientific workstation with a GUI interface.
The program is written in C with links to existing FORTRAN code to model the hydrologic process, and a commercially available graphics package.
The IFP depends on the use of a mouse driver cursor to point to and select from options that appear on the screen in popup windows.  Some of these windows also accept keyboard input.
The windows are designed to present the user with an easy to use, consistent graphical interface to the NWSRFS.