Penn State e-wall
http://www.meteo.psu.edu/~fxg1/ewall.html
A great site for viewing operational weather model data and satellite images.
NCAR Ensemble Forecasts
A site with quality graphics showing NCAR ensemble weather forecast data.
TwisterData.com
A great site for forecasting severe weather for tornado chasing, there is a lot of weather model data plotted here with beautiful graphics and a focus on convective parameters important for severe weather (although many other important model output is also plotted).
Pivotal Weather
http://www.pivotalweather.com/
Another model data image site with beautiful graphics, useful for forecasting.
BoulderCast
A localized weather forecast product and discussion site detailing the weather for the Boulder, CO area. It was created by a group of Penn State and CU Boulder alumni and I occasionally help out with Facebook posts.
NCAR Real-Time Weather
A great site for checking out satellite, radar, upper-air, and surface observation images within the last 5 days.
NEXLAB Experimental GOES-16 Satellite Images
http://weather.cod.edu/satrad/exper/
A cool new site with some amazing high-resolution satellite images from the new GOES-16 geostationary satellite (soon to become GOES-East).
SSEC Satellite Images & Data
http://www.ssec.wisc.edu/data/
A good site for real-time satellite images from many different satellites and products.
NRCS SNOTEL Data & Products
https://www.wcc.nrcs.usda.gov/snow/
A good place to find information on US snowpack in the mountains of the western US and Alaska.
US National Snow Analysis
http://www.nohrsc.noaa.gov/nsa/
A great place to go to get information on snow cover, snow water equivalent, snow melt, and just about anything related to snow in the United States.
National Snow and Ice Data Center (NSIDC)
The go-to site for information on the Cryosphere (Arctic and Antarctic regions), including information on sea ice, glaciers, permafrost, and much more.
Colorado Avalanche Information Center (CAIC)
A great resource for those of you adventuring into the Colorado backcountry during the cold seasons. They have information of avalanche conditions and snowpack throughout Colorado's mountains.
OpenSnow - The Colorado Daily Snow
http://opensnow.com/dailysnow/colorado
A winter forecast discussion for the Colorado mountains and ski resorts written by Penn State alumni Joel Gratz. It's the best place to go to look at powder (snowfall) potential for your favorite ski resort.
United States Drought Monitor
http://droughtmonitor.unl.edu/
A great place to check out the drought conditions for the US.
Wasatch Weather Weenies Blog
http://wasatchweatherweenies.blogspot.com/
A fun blog by Dr. Jim Steenburgh (aka Professor Powder) about weather, snow, and skiing with a focus on the Salt Lake City, UT area and the surrounding Wasatch Mountains.
METED
The MetEd website provides education and training resources to benefit the operational forecaster community, university atmospheric scientists and students, and anyone interested in learning more about meteorology, weather forecasting, and related geoscience topics.
14ers.com
The place to go when looking to hike a 14,000 foot mountain in Colorado. They have trip reports, conditions, and provide trail info for your trip.
NOAA ESRL Outreach - Measuring Greenhouse Gases: Behind the Scenes
http://www.esrl.noaa.gov/gmd/education/behind_the_scenes/
I helped create this website with a fellow undergraduate student while working with NOAA's Carbon Cycle Greenhouse Gases (CCGG) group over the summer of 2011. It gives an inside look on how NOAA monitors global greenhouse gas concentrations. You can look into the labs at NOAA's Earth Systems Research Laboratory (ESRL) and learn what goes on in each.