Surface Observations
RAP page: http://weather.rap.ucar.edu/surface/
National mesonet (good source of 5-min ASOS): http://mesowest.utah.edu/
Oklahoma Mesonet data/meteograms: http://www.mesonet.org/
U.S. wind map: http://hint.fm/wind/
Global wind map: http://earth.nullschool.net/
Station identifications/info: https://www.weather.gov/tg/siteloc
METAR conditions/observations: https://www.aviationweather.gov/metar
Plymouth State weather maps: https://vortex.plymouth.edu/
Upper Air Observations
RAP page: http://weather.rap.ucar.edu/upper/
U. WY soundings (various formats; global): http://weather.uwyo.edu/upperair/sounding.html
Real-time QG diagnostics: https://inside.nssl.noaa.gov/tgalarneau/real-time-qg-diagnostics/
European data (upper air and other): http://www.wetterzentrale.de/topkarten/fsavneur.html
Storm Prediction Center Soundings: https://www.spc.noaa.gov/exper/soundings/
College of Dupage (upper air and other including isentropic maps): https://weather.cod.edu/analysis/
Weather Models
Earl Barker’s model page: http://www.wxcaster.com/models_main.htm
NCEP model guidance (inc. ensembles): http://mag.ncep.noaa.gov/model-guidance-model-area.php
UKMET model output: http://meteocentre.com/numerical-weather-prediction/forecast-systems.php?mod=ukmet
GEM model output: http://meteocentre.com/models/models.php?mod=gemglb&map=na&run=00&lang=en
PivotalWeather (many models): http://www.pivotalweather.com/
TwisterData (NAM, GFS, RAP; point soundings): http://www.twisterdata.com/
High-resolution Rapid Refresh (HRRR) site: http://ruc.noaa.gov/hrrr/
Rapid Refresh (RAP) site: https://rapidrefresh.noaa.gov/RAP/
Sounding generator: http://rucsoundings.noaa.gov/
MOS guidance: http://www.wxcaster.com/models_text.htm
SREF Plume Viewer from SPC: https://www.spc.noaa.gov/exper/sref/srefplumes/
Severe Storms
Storm Prediction Center: https://www.spc.noaa.gov/
Storm Events Database: https://www.ncdc.noaa.gov/stormevents/
NOAA Storm Data: https://www.ncdc.noaa.gov/IPS/sd/sd.html
Global lightning activity: http://en.blitzortung.org/live_lightning_maps.php
Tropical Weather
Joint Typhoon Warning Center: https://www.metoc.navy.mil/jtwc/jtwc.html
Naval Research Lab tropical cyclones: http://www.nrlmry.navy.mil/tc_pages/tc_home.html
UW-Madison tropical cyclones: http://tropic.ssec.wisc.edu/
Tropical Tidbits: https://www.tropicaltidbits.com/
Cyclone phase space diagrams: http://moe.met.fsu.edu/cyclonephase/
Forecast of several types of waves: https://ncics.org/portfolio/monitor/mjo/v1/
ENSO monitoring: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml
Satellite Imagery
COD page (includes GOES-16): http://weather.cod.edu/satrad/
NASA Satellite Data Page: http://weather.msfc.nasa.gov/GOES/
RAP page: http://weather.rap.ucar.edu/
Environment Canada (Arctic/polar orbiting): http://weather.gc.ca/satellite/index_e.html#hrpt
Radar Data
NCAR Radar Data: http://weather.rap.ucar.edu/radar/
National Weather Service: https://www.weather.gov/Radar
College of Dupage: https://weather.cod.edu/satrad/
Archive Data
WPC Surface Analysis Archive: https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive.php
Archive Data Database: https://chubasco.niu.edu/1/archives.html
Level 2 radar data archive: https://www.ncdc.noaa.gov/nexradinv/
NEXRAD data on Amazon Web Services: https://s3.amazonaws.com/noaa-nexrad-level2/index.html
Archived data from 1996 – current: http://www.mmm.ucar.edu/imagearchive/
Plymouth State archive: https://vortex.plymouth.edu/myowxp/
U. Wyoming global sounding archive: http://weather.uwyo.edu/upperair/sounding.html
NCDC’s geodata portal: https://gis.ncdc.noaa.gov/maps/ncei
NCEP renanalysis data: http://www.esrl.noaa.gov/psd/data/reanalysis/reanalysis.shtml
Plot monthly/seasonal historic maps: http://www.esrl.noaa.gov/psd/cgi-bin/data/narr/plotmonth.pl
Plot daily historic maps: http://www.esrl.noaa.gov/psd/data/composites/day/
Past weather numerical data: https://www.timeanddate.com/weather/
Miscellaneous Sites
Extratropical cyclone atlas: http://www.met.reading.ac.uk/~storms/
Air quality: https://airnow.gov/, https://gispub.epa.gov/airnow/
Drought Monitor: http://www.drought.gov/drought/
NAO monitoring: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao_index.html
Environment
Atmospheric optics: http://www.atoptics.co.uk/
World weather agencies: https://worldweather.wmo.int/en/home.html
Northern Hemisphere snow cover and anomalies: https://climate.rutgers.edu/snowcover/
Global Weather Model: https://earth.nullschool.net/
Canadian Weather: https://weather.gc.ca/canada_e.html
National Weather Service Climate Data: https://w2.weather.gov/climate/index.php?wfo=oax
National Weather Service Forecast Offices: https://w2.weather.gov/climate/
Case Study Kit: https://www2.mmm.ucar.edu/imagearchive/
Shark Tracker: https://www.ocearch.org/tracker/