The TAMIR products are available on the EFAS website under the tab for Flash Flood layers (Fig. 1)

Figure 1. Example of the TAMIR flash flood products loaded into the EFAS webviewer. The functionalities to load and manipulate the products are highlighted in red.

Available Products:

The following TAMIR products are available on the EFAS website when the Flash Flood layers tab is selected:

  • TAMIR Catchment Summary:
    • TAMIR - Impact Max 0-6 Catchment Summary
    • TAMIR - Impact Max 07-24 Catchment Summary
    • TAMIR - Impact Max 24-48 Catchment Summary
    • TAMIR - Impact Max 49-120 Catchment Summary
  • TAMIR - impact forecasts
  • TAMIR - total precipitation 80th percentile
  • TAMIR 24-h accumulations

Suggested Workflow for Analysing Flash Flood Impact Layers

When viewing the animated TAMIR - impact forecasts layer it can be difficult to identify specific locations and timesteps which may be affected by flash flooding. This is partly because when zoomed out it is very difficult to see the shaded 1 km grid cells. To solve this, the following workflow is recommended:

  1.  Load in the TAMIR Catchment Summary layer for the forecast leadtime horizon window of interest e.g. load in the TAMIR - Impact Max 0-6 Catchment Summary if you are interested in the first 6 hours of the forecast leadtime horizon. Also load in the TAMIR - impact forecasts layer
  2. Use drop down menu above the animation slider to select the forecast date and time of interest
  3. Use the TAMIR Catchment Summary layer to identify the specific sub-catchments which are highlighted as being at risk of flash flooding during this forecast horizon
  4. Zoom in closer to the highlighted subcatchments of interest
  5. Use the animation slider to animate the TAMIR - impact forecasts layer to identify the specific 1 km grid cells and timesteps where flash flood impacts are possible
    1. It may help to display this layer on top of the catchment summary layer within the legend window and you may also wish to increase the opacity of the catchment summary layer (by moving the orange circle within the legend window to the left hand side)

The visibility of the TAMIR - impact forecasts layer can be improved by changing the map background to show country borders only, this can be toggled from the top right of the webviewer, it is the icon to the right of the WMS icon

Selecting Forecast Date

If one of the TAMIR Catchment Summary layers or the TAMIR 24-h accumulations layer are chosen and no other TAMIR layers are already loaded in the EFAS webviewer, then by default the data will be loaded for the date which matches the date in the top right above the legend window. Different dates can be selected using the date selection box in the top right above the legend window, but please note that it will only be possible to select data produced at 00 and 12 UTC on each day.

To select data produced at a specified hour within the past 5 days:

  • Firstly either the TAMIR - impact forecast or the TAMIR - total precipitation 80th percentile layer must be chosen from the Flash Flood layers tab. 
  • An animation slider will appear in the bottom left of the webviewer (Fig. 1). Immediately above the animation slider is a drop down menu from which the specified date and time can be selected
  • Once a date and time has been selected, this is automatically applied to all the TAMIR layers displayed in the legend window

Animation Slider:

When either the TAMIR - impact forecast or the TAMIR - total precipitation 80th percentile layers have been selected, it is possible to visualise each timestep in the 120 h forecast leadtime horizon using the animation slider. The buttons on the left hand side can be used to animate forwards or backwards for a single step, or animate the entire forecast horizon in a loop. When animating each timestep, it can take a few seconds to load the next timestep, this is shown by a loading icon which appears within the animation slider which will disappear once the next timestep has been loaded.

The animation slider box is shaded in white for the first 6 hours of the forecast horizon, this represents the horizon during which radar nowcasts are blended with the ECMWF ensemble NWP. For the remaining timesteps the animation slider box is shaded red, this reflects that the forecast is derived from ECMWF ensemble NWP only.

For the first few hours of the forecast horizon the timestep of the forecast is 1 hour, after this the timestep becomes 6 hourly. Typically the first 6 hours of the forecast will have a 1 hour timestep, but this could be longer depending on the time of day when the forecast was produced. A box is displayed above the animation slider which shows the size of the current timestep which is being shown in the animation slider.