NOAA and the FAA operate a nationwide network of surface weather observation stations (ASOS/AWOS -> Automated Surface/Weather Observation Stations) to facilitate standard atmospheric measurements for use in both meteorology and climatology. These stations house several instruments including thermometers, anemometers, disdrometers, and electronic rain gauges.
Data from these stations are easily visualized using standardized symbols on maps which quickly indicate many parameters such as wind speed and direction, temperature, dew point, cloud cover, precipitation type and rate, and pressure. Understanding how to read these maps is a useful skill for the SKYWARN Spotter, as they condense a large amount of information into a compact format with spatial reference.
Conditions from the automated surface stations are often used by pilots (and other users) in a form known as METAR (METeorological Aerodrome Report). More information is available at these sites:
METAR symbols (slightly less than all possible condition symbols): https://www.aviationweather.gov/metar/symbol
The NWS has a helpful guide available on their JetStream Online School:
- Weather Prediction Center Interactive Surface Analysis (includes archive): https://www.wpc.ncep.noaa.gov/html/sfc-zoom.php
- Weather Prediction Center Static Surface Maps: https://www.wpc.ncep.noaa.gov/html/sfc2.shtml
- NWS Norman Surface Maps: https://www.weather.gov/oun/sfcmaps
- Storm Prediction Center Surface Observations: https://www.spc.noaa.gov/exper/surfaceMaps/
- NWS Corpus Christi Interactive Map: https://w2.weather.gov/crp/observations
- Aviation Weather METAR map: https://aviationweather.gov/metar
- College of DuPage analysis: https://weather.cod.edu/analysis/
- Pivotal Weather Real-Time Analysis: https://www.pivotalweather.com/maps.php?ds=rtma_ru
- TropicalTidbits (aimed at tropics): https://www.tropicaltidbits.com/analysis/sfcplots/