Share GRIB files with Air Share [Update]

You are more likely to have adopted the Iridium GO! for its easy way to request GRIB files, directly from Weather4D and some other applications. But some also want to transfer these files to PC to import them into Windows software (as you know, nobody is perfect !). An easy solution is available : the messaging app Air Share, compatible iOS/iPadOS (¹). [Update 30 March 2022] Warning : the app has changed its ID code on the AppStore. Read more …

ECMWF weather data soon open to the public [3rd part]

Trafalgar Hit for the flagship of European meteorology, despite Brexit and contrary to what had been planned (¹), the European Center for Medium-Range Weather Forecast will stay in England ! Even better, a new headquarter for ECMWF to be fully funded by the UK government through the Department for Business, Energy and Industrial Strategy. Proof that the British have gone all out to keep this European scientific center in Reading (²). Read more …

Are GRIB files consistently optimistic ?

This question has been asked regularly, but until now I had never wanted to publicly give my opinion on the subject so as not to offend anyone and especially not to create unnecessary controversy. But by dint of doing it during my training, why not express it openly ?

My opinion, forged by observation and a long professional experience in pleasure boating (¹), is that this assertion of the systematic optimism of the GRIB forecasts regarding wind force, which unfortunately continues, no longer has a reason to be, and has not been verified in fact for some time. Read more …

Alternative weather models [Update]

[Updated 29 July 2022]

For several years, forecast files in GRIB format have been widely used in meteorological applications.. The majority of forecast models have been made freely available by the meteorological services, all countries included. Applications like XyGrib, LuckGrib, SailGrib, Weather4D and other, offer a selection of atmospheric and oceanic models, up to 25 weather models and 15 waves and currents models for Weather4D, more than thirty models with LuckGrib, in example. But there are always others that can usefully complement the standard offerings of these applications.. Read more …

Predict thunderstorms with Weather4D


In Weather4D (all versions) most weather models provide a data calledCAPE.

Convective Available Potential Energy, in French : Energie potentielle de convection disponible. Behind this abstruse acronym hides a powerful tool for forecasting thunderstorms. The CAPE is measured in joules per kilogram of air (J / Kg) and defines the vertical thrust energy of a hot air particle in a colder atmosphere. In other words, vertical acceleration of the air particle will be directly related to this energy measurement. Read more …

Reading : "Clouds and other meteors" Météo-France

In an article updated in August 2020 (¹), I have described nautical books in digital format that can be usefully saved on iPad in the Apple Books app. Among them I mentioned the works of Météo-France available in PDF format for free download from their documentary portal.

In the “Courses and Manual” section of this site, we can download a new book, published 2020, entitled "Meteorological Observations and Measurements – Tome 1 / Clouds and other meteors ", a veritable mine of information on clouds, and all associated meteorological phenomena, called "meteors" (²). Read more …

You said « Medicane » ?

Many sailors who cross the "Big Blue" have known for ages that, if the navigation is relatively easy, the weather represents a particularly difficult constraint to deal. Indeed, if the coasts are mostly clean and the dangers very localized, if the tides are almost insignificant, if the currents are to be considered only in well defined areas, the major difficulty comes from a capricious meteorology, difficult to forecast, which can represent a real danger by its changing moods, sudden, even rough. Read more …