The PredictWind app for Apple and Android smartphones and tablets is a handy way for sailors to stay in touch with the wind and weather. Not long ago you'd tune in NOAA weather radio for the marine forecast covering a large area to receive something like this (my own forecast today - compare with PredictWind's forecast below): "SW WINDS 15 TO 25 KT...INCREASING TO 20 TO 30 KT THIS AFTERNOON."
The forecast above is a good example why sailors need a forecast that is as specific for their immediate area as possible. Say it's 10:00 AM and I'm thinking of going sailing for a few hours. A breeze of 15 would be great for my boat: maximum speed without having to reef. But if it hits 20 as soon as I leave the dock, I'd better be reefed down (and maybe have experienced crew with me, depending on my boat's rig) - and if it's blowing 30 about the time I reach open water, I'd better get back in unless I want a wild, wet ride and crew who can cope with the difficulty of picking up my mooring once the waves grow in my harbor.
PredictWind gives a forecast for a much more specific area and maps out expected wind changes by the hour. In contrast to the particular NOAA forecast above, I see 15 knots at 1 AM today, but by 10:00 AM it's already 22 knots. But it will stay in the low 20s all afternoon, rising over 25 only well after sunset. So I know to expect a good wind (reef before heading out), but I also know it won't reach that 30 in my area until midnight, so I'm good to go with my present crew.
That is exactly what PredictWind was designed to do and does best.
Version reviewed: PredictWind for Android free version 2.1.1
Tested on Lenovo A1 Tablet running Android 2.3
Available for both Android (1.6 and up) and Apple devices
Key Features of the Free Version
You begin by choosing your local forecast area. One area is saved in the free version (but it can be changed when you go elsewhere); six in the paid versions. Then you get a menu for a variety of specific functions and types of information.
Following are the basic features in the free version:
- Wind speed and direction forecast hourly for 24 hours (5 days in paid versions)
- Wind data presented in a variety of visual formats: table, graphs, map animated with wind arrows, animated contour map (see image above)
- Predicted wave height, period, and direction (coastal and offshore areas) hourly for 24 hours; tabular information and also animated contour maps
- Air temperature (over the water - not over land) forecast by hour
- Rainfall and cloud cover forecast by hour (table) or in 3-hour increments in animated contour map
The PredictWind website explains that the wind forecast uses their own computer model based on NOAA and Canadian Meteorological Centre data, and most functions allow you to compare both to determine which most accurately matches your local observations. In my testing, the forecasts seemed as accurate as one would expect - subject to the fallibility of all forecasting. (In today's example, given above, the wind actually later hit sustained 33 knots at 3 PM according to my local NOAA buoy report - much earlier than in the PredictWind forecast and exceeding the NOAA forecast. One should always be cautious with forecasts!)
- It would be nice to have help screens on the app device explaining the different data formats and sources. You have to go to the Predictwind.com website presently for this information.
- The time (at top of forecast table) is not seen when you scroll down to lower-table info, so you have to scroll up and down to see what time periods the data refers to.
- Different functions treat time somewhat differently. For example, as I write this at 12:30 PM, my forecast table gives a wind forecast by the hour starting at 1 PM today for the 36 hours ahead, but my wind forecast map animation starts at 4:00 AM this morning and continues for 24 hours, and my wind forecast contour map animation starts at 10 PM last night and goes only to 4 PM this afternoon. There must be technical reasons for this, but I find the shifting time frames confusing.
Additional Features of the Paid Versions
Unlike most apps with a single price for additional features, PredictWind uses a subscription model. Expanding from a 1-day forecast to a 5-day forecast costs $9 for 3 months or $19 for 12 months. In addition, for $5/hour you can obtain weather routing functions, or $5/hour for the trip planner. It is difficult to know precisely how these last two features function without paying first, as the developer's website has an altogether different pricing structure for a grid of features (called Basic, Standard, and Professional) referring their computer program rather than the app.
Since I doubt most recreational sailors need these other functions, I did not investigate them further; I would guess that the NOAA or CMC extended forecasts would be sufficient for most sailors. The upgrade apparently also provides current wind and other observations in addition to the forecast - but this information is already available through other weather apps (such as Marinecast or Wind NOAA) or via NOAA buoy reports obtainable also on your Android or Apple device.
For what it does, the PredictWind free version is a good app for sailors to have in their toolbox, along with a tide and current app, chart navigator, and others. I especially like the primary table that gives the hourly forecast for all relevant weather variables in a clear, quick-glance format, along with the animated contour maps that show changes moving into the area. Darn good stuff for a free app!
To complement PredictWind’s forecast, check out the free version of Marine Weather for both Apple and Android devices, which includes lots of weather data, tides, radar, and more.
Start here to consider a wide range of sailing and boating apps you may be interested in.