In this task, we will load gridded precipitation data from DSS for a specific time window and observe the computed storm totals by subbasin.

Load Gridded DSS Data.

Expand the "Radar" Map Window Node in the HEC‐MetVue Explorer Window.

Right‐Click on the TIN node and click on "Select DSS paths…"

Open the Windows Explorer browser by clicking the ellipsis (...) next to the "Catalog DSS.." button.

Make the following DSS file selection:

...\HEC-MetVue_Overview_Start\HEC-MetVue\Data\DSS\BaldEagle.precip.2018.09.dss

Filter the DSS Catalog to display only the NEXRAD gridded records by selecting the drop-down menu next to the F-Part and selecting "NEXRAD." 

Scroll towards the end of the catalog and highlight the gridded precipitation records from 07Sep2018 1100 to 11Sep2018 1100.

Press the "Add Sel" button.

Notice that pressing "Add Sel" transfers the selected records down into the lower selection box signifying that these records will be added to the HEC-MetVue Map Window.

Press OK to close the selection editor and observe how HEC‐MetVue performs accumulation computations (notice the progress bar notification at the bottom right corner of the main HEC‐MetVue Interface).

The cumulative statistic grid for the 7-11 September 2018 storm event will be computed before getting loaded into the Map Window.

View Gridded DSS Data.

When the computations are done, observe the statistic grid for the September 2018 storm covering the northeast region.

Zoom in closer to the Bald Eagle watershed to view the computed basin average storm totals. 

Question: When might viewing precipitation event totals be useful?

Visualizing precipitation event totals is useful for a variety of scenarios, such as:

  • reservoir regulation planning
  • communicating with stakeholders
  • determining "hardest hit" areas
  • & many more!

Question: What is the total precipitation for the September 2018 event within the Sayers LOC subbasin?

From the Bald Eagle-Radar map window, we see that the basin-average precipitation total within the Sayers LOC subbasin for the September 2018 event is 5.98 inches (23,938 acre-feet).

We could also find this value within the tabulated HEC-MetVue output located below the Bald Eagle Session:

Once data has been added to the map window, there are various tools within HEC-MetVue that allows the user to manipulate the gridded data. 

Tasks

Part A – HEC-MetVue Orientation:

Part B – HEC-MetVue Data Input:

Part C – HEC-MetVue Precipitation Preprocessing for input into HEC-HMS :