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You will start by studying the evolution of the ECMWF analyses and forecasts for this event. You will then run your own OpenIFS forecast for a single ensemble member at lower resolutions and work in group to study the OpenIFS ensemble forecasts.

Recap

ECMWF operational forecasts consist of:

  • HRES : T1279 (16km grid) highest resolution 10 day deterministic forecast
  • ENS :   T639 (34km grid) resolution ensemble forecast (50 members) is run for days 1-10 of the forecast, T319 (70km) is run for days 11-15.

 

Note
titleCaveat

In practise many cases are aggregated in order to evaluate the forecast behaviour of the ensemble. However, it is always useful to complement such assessments with case studies of extreme events, like the one in this exercise, to get a more complete picture of IFS performance and identify weaker aspects that need further exploration.

Recap

ECMWF operational forecasts consist of:

  • HRES : T1279 (16km grid) highest resolution 10 day deterministic forecast
  • ENS :   T639 (34km grid) resolution ensemble forecast (50 members) is run for days 1-10 of the forecast, T319 (70km) is run for days 11-15.

 

 

Info
titleSaving & printing

 To save images during these exercises for discussion later, you can use:

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"Export" button in Metview's display window under the 'File' menu. This will also allow animations to be saved into postscript.

or

Code Block
languagebash
titleUse the following command to take a 'snapshot' of the screen:
ksnapshot

 

Printing. If hardcopy prints are desired please use the printer at the rear of the classroom and only print if necessary.

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titleOutline of exercises
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Gliffy Diagram
nameexercise flowchart

 

 

 

Exercise 1.

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Visualise the ECMWF

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analysis of the St Jude storm

 

Objective: Understanding (a) the formation of the storm (b) the error in the forecast by comparing the ECMWF forecast with analysis & observations

Starting up metview
Code Block
titleType the following command in a terminal window
metview
Info

Please enter the folder 'openifs_2015' to begin working.

Task 1: Visualise observations and ECMWF analyses

 

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titleMetview icons

For this task, use the metview icons in the row labelled 'Analysis'

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titlePlot wind gust observations

 1. Right-click on the icon labelled 'wgust_obs.mv' and select 'Visualise' (or Control-I on the keyboard) THIS MAY CHANGE

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titlePlot analyses in various layouts

Icon 'an_1x1.mv' produces a single plot on the page.

Icon 'an_2x2.mv' can produce up to 4 plots per page.

 

Info
titleChange plot fields

For the 'an_1x1.mv' icon, the plot contents can be changed by editing the plot1 variable in the macro. By default the 10m wind is shown.

To alter the plotted field, right-click and choose 'Edit'.

It is possible to overlay multiple fields like this:

You will find a list of available parameters in the macro.

After editing the macro text, you can optionally save using the 'File' menu and 'Save'.

Display the plot by clicking:

Animate the plots in the display window by clicking

Info
titleChange plot appearance

 The number of maps appearing in the plot layout can be 1, 2, 3 or 4.

Macro an_2x2.mv demonstrates how to plot a four-map layout in a similar fashion to the one-map layout. The only difference here is that you need to define four plots instead of one.

Right-click on the icon and select 'Edit'. Change the plot layout like this:

Two map types are available covering a different area.

With mapType=0, the map will cover a smaller geographical area centred on the UK.

With mapType=1, the map will cover most of the North Atlantic

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