Forecaster is a modern weather app for the Mac and iOS. It provides a simple and clear forecast for weather locations you select. If snow is in the forecast you will actually get the predicted snowfall total and not just an icon that leaves you wondering. If the location you select is a body of water you will get a marine forecast, letting you know how big the waves will be. It gathers its forecasts from NOAA and therefore is only available in the United States and its territories.
Some of the unique features of Forecaster are that it updates the dock icon with the temperature of your current location. It has a clean and easy to use interface, and provides a great map view.
Adding new locations is as easy as centering the map on the location, creating a name for the location, and saving it. The saved locations are synced across your computers through iCloud, so you will only ever have to maintain a single list of locations.