Low humidity should be located behind a front and near highs. Precipitation map - Shows the location and intensity of precipitation. This map is usually the best guidance for a precipitation forecast. If images from the last few hours are looped the motion of the atmosphere is seen so you can see air mass movement. You can analyze the wind vectors and find out where the high and low pressure systems are located.
Winds circulate counterclockwise around a low and clockwise around a high.
These maps show the average high and low temperature across the U.S. for a given date, based on long-term climatological averages. They serve as a good reference with which to compare one's forecasts. Don't get caught up to much in computer model guidance, though. The best forecast is made by utilizing data from the computer and applying your own meteorology skills in making a forecast. A good place to start is the National Weather Summary, which gives one an overview of the significant weather over the past 24 hours as well as a indication of where significant weather will be occurring during the next 24 hours.