WMS:HEC-HMS Defining the Meteorological Model

Define meteorologic data for the model by selecting the Meteorologic Parameters menu item from the HEC-HMS menu.

Selecting this menu item will bring up the HMS Meteorological Model dialog. This dialog is used to assign precipitation data to all the basins in the model.

HMS Meteorological Model dialog

The same precipitation method must be assigned to all the basins in the HMS model. The precipitation method choosen should be based on the type of analysis to be run. If having rainfall gage data for the watershed, use the user hyetograph or the user gage weighting method. If wanting to create a synthetic storm with a known exceedance probability, select the frequency storm method. If wanting to model a standard project storm, select the standard project storm or the SCS hypothetical storm method. Only use the No Precipitation option if the HMS model does not have any basins. See the topics below for more detailed information about the HMS Meteorological Model dialog.

HEC-HMS User Hyetograph

The User Hyetograph method can be used if a hyetograph is known for each sub-basin of the watershed being modeled. Get this hyetograph from recorded data or from any other method. Enter the same or different hyetographs for each basin, but each basin can only have a single hyetograph. Define the hyetograph by clicking on the XY Series button in the HMS Meteorological Model dialog shown below, and define the hyetograph in the XY series editor:

HMS Meteorological Model dialog for the "User Hyetograph" method.

Related Topics:

• Frequency Storm
• Gages
• Convert Grids (NEXRAD Radar rainfall grids)
• SCS Hypothetical Storm
• Standard Project Storm
• Meteorological Options
• HMS Overview