The Offshore App is designed to save PredictWind weather information in an offline mode, great for boats heading offshore with a need to download forecast GRIB files on an Iridium GO, GO! exec, Satellite connection or coastal cruising where a cellular network is intermittent. Once the files are downloaded, they are stored locally on the device for you to review at any time offline.
To download GRIB files, weather routing and departure planning etc using a Windows 10/11 computer or Mac computer you need to use the PredictWind Offshore App which can be downloaded here
The Offshore App is available to be used on all connection types.
The Offshore App can be used on high-speed internet, 4G/5G cellular, satellite or email connections.
When you first start using the Offshore App, we recommend you practice on a high-speed internet connection using the WEB Tab (home Wi-Fi or a cellular connection).
How to use the Offshore App on a PC or Mac video, a must view
Basic Instruction to get you started
Move your green start waypoint and your red destination waypoint to your desired locations.
The GRIB areas are automatically set up when adjusting the route. You can manually adjust this area by dragging the corner (white dot) of the GRIB box. You may wish to make the GRIB area bigger.
Click on the green download button.
You are now on Download Preferences Page, this is where you select what you want to download.
Select the Download method, Starlink users would use the WEB option. GO exec the GO exec option.
Select GRIB 50km or 100km resolution to download a GRIB area for your passage. When downloading over a Satellite connection we recommend using All Models, 24 hour timestep,5 days, 100km resolution, wind, rain and pressure. Highest resolution GRIB files are generally too large for downloading over a satellite connection. Treat the GRIBs as a general synoptic overview. You are best to get the detailed weather information using the Weather Routing results.
Select Weather Routing, Start time NOW
Then Click Next , then Download All and then wait for your files to download.
Once the entire download is complete you will be able to view Weather Routing results in Table and Map format. In Tables we have graphs, wind, summary, route, wave etc. You are able to toggle between Table and Map view and the information is saved for offline viewing. Graphs are a great place to start to give you a snap shot overview of the route.
Previous data that you have downloaded will be removed from the display, so that you are only viewing the most current forecast.
GRIB maps can be viewed in three formats
The wind can be displayed in 3 formats - arrows with pressure contours lines, Wind Barbs with pressure contours , and directional arrows with pressure contour lines . All 3 formats show the same data, so you can choose your favourite format. Changes are made within the Forecast Options box.
Other Controls
To animate the GRIB file use the play button. You can also use the left/right arrows to manually animate the weather at your own pace. The date/time is shown in the time zone of your Laptop next to the legend. In addition you can click on the animation time slider to jump to a specific day. For example Monday. Select the O and you get back to the NOW time.
You can switch between the forecast models by clicking on Wind icon bottom right this brings up the Forecast Options box so you can choose between PWG/PWE/GFS/ECMWF/SPIRE/UKMO to get a comparison of the top 6 weather models.
In addition you can view Rain/Gust/Cloud/Air temp/Wave/CAPE If you have not selected one of these to download will be greyed out and not available.
High Resolution GRIB
To view the high resolution GRIB areas select GRIB highest resolution. Only 1 high resolution GRIB area can be viewed at a time. Select this area by clicking on the yellow square. Please note that you can only view high resolution areas that you have downloaded, the yellow squares. The high resolution areas contain more data and therefore take a fraction longer to display.
Additional Tips
The Weather Routing is the best tool for updating your forecast during your passage. The file size is very small (approximately 25kB) so quick to download. You should update the Weather Routing every 12 hours when the forecast models update. The data set available in Weather Routing Tables is vast, simply looking at GRIBs to make decisions, important information is missed.
• You do not need to download any GRIB files for the weather routing to be calculated, as the processing is done on the PredictWind servers in the Cloud.
• Please note, the forecast will run for a maximum of 10 days. Beyond 10 days, the model forecast is not accurate. We use the ECMWF ensemble. For the ensemble model, we download all 101 members of the ECMWF ensemble and use AI to match the ensemble member that most closely matches the 10-day ECMWF forecast; the member is then used for the 10-30-day forecast. Every 12 hours, we run this AI matching process to update the closest ensemble member. If you use the routing on the website and the PredictWind App, you will see the ECMWF Ensemble data load in the maps after 10 days.