Polar wind plots that combine wind direction and wind velocity - Delft-FEWS

A mock-up of the polar plot is shown below. The plot is valid for a single location. At any point in time, a dot represents both direction (angle from the origin) and speed (distance from the origin). Lines connect the dots, to show how a timeseries evolves in time. Critical thresholds that comprise both a range of speed (e.g., “over 8 m/s” or “between 8 m/s and 10m/s”) and direction (“between 280 and 300 degrees”) can be shown in the plot through shading in various colours. The plot will then immediately show how many points are within that shaded area; this is indicative for the duration of threshold exceedance. This indication may prompt an officer to explore the more traditional timeseries.

Some additional information/ideas/characteristics:

* “Valid time” of the points will be shown in a tooltip, upon hovering over the points.

* A time slider will allow for highlighting individual points.

* Possibly, the line can be colour-coded as to be indicative of  lead time (as shown in the mock-up)

* The values indicating speed will likely be plotted along the 0-degree axis (rather than outside the plot as is the case in the mock-up).

* The plot would allow for showing ensemble forecasts also, by simply adding more lines. While the plot will become quite crowded, it will give an initial sense of probability of threshold exceedance

Note: this plot is likely to be used in combination with 'traditional' timeseries plots of the two variables.

Nota bene:

1. The development of this feature is estimated to cost approx 20 days of developer time. 5 of these have been pledged by Natural Resources Wales. We are looking for organizations that contribute to the remaining 15 days.

2. Present idea should be interpreted as 'draft' which can be modified!

Additional information about the polar wind plots can be found in this document.