Using the Hydrologic Ensemble Forecast Service (HEFS)

### Produced by The COMET® Program

### 3.0 Developing Products from Hydrologic Ensembles » 3.3 Box Plot Example

### Box Plots

### Spaghetti Plot (Ensemble Traces)

Here is the box plot representation of the ensemble traces that we studied earlier. Click the tabs to see the actual ensemble traces. Recall that earlier, you outlined the middle 50% of the ensemble members—that’s what the box portion of the box plot represents. Beyond Day 4, when most ensemble members are near 0, only the highest members show up in the whiskers portion of the plot.

#### Activity

Use the drawing tool to trace the 50% and the 5% exceedance probability through the time series. Then click Done.

1. Use the purple pen to draw the 50% exceedance probability
2. Use the orange pen to draw the 5% exceedance probability

Tool: | Tool Size: | Color:
--- | --- | ---
Pen Eraser |  |

The graphic shows the median (50% exceedance probability) and the 5% exceedance probability, which connects the top whiskers in the box plot.