As a general rule, in flight, you'll only have access to what you last viewed on the ground except for Radar and Satellite Maps. To "preflight" your weather data, do the following:
1. View the Airport pages for departure, destination, alternate and other airports of interest.
2. View at least 1 fuel map. This will get you all data for both fuel maps: Jet A and 100LL.
3. View at least 1 of the METAR-based maps (TFRs, AIR/SIGMETs, Flight Rules, Temperature, Dewpoint Spread, Visibility, Wind, Ceiling, Sky Coverage, PIREPs, and Lightning). This will get you all data for all of these maps.
Radar maps, Satellite maps, and Imagery are not downloadable.