Snow at
Cerro Paranal
on July 22, 2000

Verification pages

Welcome to this page. It will provide some tools to show the accuracy of the ECMWF predictions compared to the observed data. The forecasts at the site location are extracted from the ECMWF data cube using a bilinear interpolation on the four nearest points of the ECMWF grid. Then a cubic spline interpolation is used for the vertical axis at the pressure predicted for the altitude of the site.

The data is then Kalman filtered to remove systematic non-linear biases on the basis of a learning database of the past 14 days containing the ECMWF analysis, the ECMWF forecasts at +6h and +12h and the corresponding observed data.

This process deals with three main parameters at ground level: the temperature, the pressure and the wind speed. For now, it is only available at La Silla.

The accuracy of the original and of the Kalman filtered forecasts is monitored as part of the general forecast verification scheme.

Telescope Enclosure Thermal Control: predicted sunset temperature can be retrieved using this sample script.

The following topics are available:

Graphics showing the evolution of the three parameters.

Graphics showing the repartition of the pairs (prediction,measure).

Some statistics about the predictions and the kalman filter.

200mb wind speed.