Meteorological Forecasts at ESO Sites

Welcome to this site. It provides informations regarding the meteorological conditions above ESO observatories. An Introductory Presentation is available for new-comers, as well as an update of the performances after one year of operation. Hints for the terminology are available in the Weather Glossary.

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Cloudiness and Water Vapour from Satellite Images

Your Sky RECENTLY : GOES satellite images of Northern Chile (updated every 15mn).

Cloudiness, PWV, Synoptic Meteorology, Jet Stream and Ground Conditions forecasts from ECMWF global model (internal access)

Note from ECMWF:
"ECMWF products are provided for the sole use of ESO and cannot be passed to a third party. Graphical displays of ECMWF data over the open internet is thus not permitted."

ASM display for Science Operations (login required).

ASM display for Safety (login required).

The meteorological images are refreshed every 6 hours, as soon as the provider (ECMWF) sends the forecasts (about 7h after the initialization time). They include short term predictions, up to T+90H, with a step of 1 hour. The 00UT and 12UT forecasts also include general tendencies up to T+168 hour (7 days) with a step of 3 hours.

The first pages provide general tendencies for the south Pacific and the Chilean coast. The next pages are reconstructed radio-profiles above Paranal, La Silla and Chajnantor).

Medium and High cloudiness and general tendencies for the Chilean coast (short term long term and archives)

Reconstructed radio profiles above Paranal (short term, long term), La Silla (short term, long term) and Chajnantor (short term, long term)

The forecast of ground level conditions at Paranal, La Silla and Chajnantor

Note: The profiles are constructed from a bilinear interpolation: the four nearest points of the grid are isolated and the profile computed with respect to the distance between the site and the four points.

Credits: the forecasts are produced by ECMWF (European Center for Medium Range Forecast). Two type of grid are used: the first, with a step of 3 degrees, on [65W to 110W]x[10S to 43S], and the second use a step of .125 degree on [67W to 71.5W]x[22S to 26.5S] and on [67W to 71.5W]x[27S to 31.5S].
The files are then processed using Grads scripts developped at ESO by P. Labit along the lines defined by CRS4 to produce those images. For more details, see Meteorological Forecast Products, User and Maintenance Manual ref:TRE-ESO-17443-1678.