Currents and waves at hectometric resolution from Ifremer (Episode 2)

Episode 2 – Illustrations

Forecasts IFREMER (see Episode 1) available in Weather4D are of two kinds :

    • Current forecasts from the MARS2D model
    • Sea state forecasts (combined currents and waves) based on WW3 model

These files concern areas of the Channel and Atlantic whose coverage and resolutions are significantly different. Read more …

Currents and waves at hectometric resolution from Ifremer (Episode 1)

Episode 1 – Description

Since 7 May 2024 the latest versions of Weather4D have been enriched with several new weather and ocean models (¹). Among the latter, ultra-high resolution current and wave forecast models from’Ifremer come in addition to Copernicus models (formerly called MyOcean) for the Channel and Atlantic coasts. These forecasts are provided with hectometric grids, can be reduced up to 190 meters for some models. So Ifremer, what is ? Read more …

GRIB files and time zones

An incomprehensible malfunction occurred recently for a Weather4D user, sailing in a “lost hole” on the edge of the Indian Ocean, namely the Cocos Islands, challenged me to the point of getting lost in conjectures. A GFS file due ten days ago categorically refused to be displayed in the application with the date, damn !

This unfortunate sailor - for which I would like to thank him - forced me to make a determined search for the cause of the problem.. After much procrastination, explorations of settings that may be faulty, since no other user had reported such a problem to us, the light finally came out ! Read more …

Weather4D renews its GRIB model offering

Latest releases Lite, Routing, Routing & Navigation arrive with a full renewed list of weather and ocean models in order to allow users to benefit from the evolution of the offer of international forecasting models. At the same time, all GRIB files go to format GRIB-2, this allows for a reduction in their size and a better compression ratio. Read more …

The European Union is moving towards Open Data

 

Europe is moving forward slowly, but she moves forward… towards free access to data from public services ! On September 21 December 2022 was published in the Official Journal of the European Union, under the reference C/2022/9562, The " Regulations of the European Commission establishing a list of specific high-value datasets and the modalities of their publication and re-use". Read more …

Share GRIB files with Air Share [Update]

More and more of you 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 a PC to import them into Windows software. (as you know, no one is perfect !). An easy solution is available : the messaging app Air Share, compatible iOS/iPadOS (¹). [Update 30 mars 2022] Warning : the application has changed its identifier code on the AppStore. Read more …

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

Trafalgar Hit for the flagship of European meteorology, despite Brexit and contrary to what had been planned (¹), on April 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 hotspot in Reading (²). Read more …

Are GRIB files systematically optimistic ?

I've been asked this question regularly, but until now I've never wanted to give my opinion on the subject publicly, so as not to offend anyone or create unnecessary controversy.. But after doing so many of my training courses, why not express it to me openly ?

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

Predict storms with Weather4D


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

Convective Available Potential Energy, in French : Energie potentielle de convection disponible. Behind this obscure acronym hides a powerful storm forecasting tool. CAPE is measured in Joules per kilogram of air (J/Kg) and defines the vertical buoyancy 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 …