current weather data, radar imagery, satellite imagery, weather maps

Plymouth State University Weather Center

This is an easy-to-navigate and interactive site with an incredible array of data. You can “make your own” of almost anything; and you can retrieve a large amount of “archived data.” Most of the maps you can create allow you to define location, zoom, change font size, and other attributes. The national map plot with station model data is a bit crowded, but regional maps are close to “perfect”. There’s so much stuff here that I’m still learning what is available.
Plymouth State University Weather Center

current weather data, forecasts, mesoscale, NWP, radar imagery, satellite imagery, weather maps

Pennsylvania State University E-Wall

This site has its weather information arranged as one huge “wall.” But, if you look to “nooks and crannies” and capitalize on the left margin menu, you’ll find radar and satellite data and the best 24-hour temperature change map on the web. You can also use this map to track how cold and warm fronts are moving across the U.S. This site requires a lot of self-learning to ensure you know what is posted.
Pennsylvania State University E-Wall

climatology, clouds, satellite imagery

NASA MODIS (Moderate Resolution Imaging Spectroradiometer) Satellite Imagery

This site contains current and historical (back to February 2000) satellite imagery from the polar-orbiting Terra and Aqua satellites. Flying at relatively low altitude, these satellites are able to provide very high-definition cloud, ocean, and land-based images of specific geographical regions. Because the satellite orbits as the Earth spins beneath it, there are gaps in coverage between successive satellite passes.

https://lance.modaps.eosdis.nasa.gov/realtime/?calendar