With the weather as brutal as it's likely to get this winter in much of the Continental United States, now is a great time to take a quick look at the leading free weather apps for your iPhone and iPod Touch.

Until recently, I had been using WeatherBug. It was one of the first weather apps to be released for the iPhone that did substantially more than the weather widget that ships with the iPhone. The four major features of WeatherBug are: Conditions, Radar, Video, and Cameras.

WeatherBug emphasizes the availability of data from local weather stations, a series of devices deployed at a local school, business, or hobbyists' homes that provide weather statistics. Some of these stations are co-located with webcams that show the outdoor conditions.

WeatherBug lacks some features found in some of the other popular free weather apps like direct links to the National Weather Service watches warnings and advisories in the navigation bar at the bottom of the screen. WeatherBug's implementation of support for multiple locations is also very non-standard (swiping in the part of the screen where the location name is displayed). This took some getting used to when I first installed it.

Accuweather.com is another very popular free weather app. The major functions of this app are Weather, Radar, Video, Risk, Alarms, and Alert. It's main differentiating feature is the prominent placement it gives to location-based weather forecasts, which uses Core Location to get you a truly local forecast. This feature seems to be aimed at iPhone 3G users. I haven't gotten great results from it on my first-generation iPhone.

Two other unique features of Accuweather.com are "Risk" and "Alarms" on the navigation bar at the bottom of the screen. Risk displays a screen with sliders next to five categories of adverse weather conditions. The sliders are set to the likelihood that the condition will occur within the next 8 hours. Alarms are intended to warn about daily precipitation for the next five days. It would be nice if these alarms were configurable, so I can choose what I would be warned about.

The shortcomings of Accuweather.com from my perspective are that it displays advertising. There is also an initial-use question about what the difference between "Alarms" and "Alert" is on the navigation bar. (Alert refers to advisories, watches, and warnings from the NWS.)

The most popular free weather app in the iTunes App Store at the moment is The Weather Channel®. The major functions of this app are: Weather, Explore Map, Video, Severe, and More (which reveals a small list of additional functional choices).

The main differences between TWC and Accuweather.com are that TWC provides more detailed information at a glance in its hourly forecast. The information is there with Accuweather, but you have to do some tapping. Also TWC has 36-hour and 10-day forecasts, while Accuweather has 5-day and Indices (UV and Air Quality).

The Weather Channel map-related features are much more configurable than Accuweather or WeatherBug, but some of the stuff that you can add to the map isn't weather-specific.

TWC also has the most intuitive location changing mechanism of the three weather apps I looked at. (You can't do better than a button labeled "Location" on the upper right corner of the screen.) Their Core Location support is buried in a configuration pane, but it's there if you need it.

All three apps have video-based forecasts of various types available on demand. Accuweather has several different forecast options and the ability to choose higher or lower resolution video. TWC and WeatherBug just provide a local video forecast. I'll bet that the relevance of what's available varies widely based on the size of the community that you live in.

If you are in the USA, I think The Weather Channel and Accuweather are both going to provide most of what a regular person is going to need in terms of weather information. I like some aspects of WeatherBug, but I think it is a little lighter on features, and the UI has some weirdness to it.

If anybody has other recommendations, either for the USA or other countries, I'd love to hear them.