# Weather-terms glossary. Each entry: slug, term (display name), short (one-line
# definition), body (full HTML; {base} is replaced with the app base path at load
# time). Consumed by backend/web/content_loader.py -- see docs/README.md.
terms:
- slug: climate-normal
  term: Climate normal
  short: The typical value of a weather metric for a place and time of year, averaged over decades.
  body: |-
    A <b>climate normal</b> is the long-term average of a weather variable (say, the daily high) for a specific place and time of year. Thermograph builds each day's normal from every historical day within &plusmn;7 days of that day-of-year, across ~45 years, so a day is judged against its own season, not a single annual average.
- slug: percentile
  term: Percentile
  short: 'Where a value ranks within a distribution: the 90th percentile is warmer than 90% of days.'
  body: |-
    A <b>percentile</b> says where a value falls within a range of past values. If today's high is at the 97th percentile, only about 3% of comparable days in this location's history were warmer. Thermograph grades every day by its percentile against the local &plusmn;7-day seasonal distribution.
- slug: temperature-anomaly
  term: Temperature anomaly
  short: 'How far a temperature departs from normal: the difference from the long-term average.'
  body: |-
    A <b>temperature anomaly</b> is how much warmer or colder it is than the local normal for the time of year. Thermograph expresses the same idea as a percentile and a grade (from “Below Normal” to “Near Record”), so an anomaly is easy to read at a glance for any location.
- slug: feels-like
  term: Feels-like temperature
  short: What the air actually feels like once humidity and wind are accounted for.
  body: |-
    <b>Feels-like</b> (apparent temperature) combines air temperature with humidity and wind. In heat it uses the <a href="{base}/glossary/heat-index">heat index</a>; in cold it uses <a href="{base}/glossary/wind-chill">wind chill</a>. Thermograph grades feels-like against its own local history, so “Near Record” means extreme <i>for that place</i>.
- slug: heat-index
  term: Heat index
  short: How hot it feels when humidity is factored into the air temperature.
  body: |-
    The <b>heat index</b> is the apparent temperature on a hot, humid day: high humidity slows sweat evaporation, so it feels hotter than the thermometer reads. Thermograph folds it into the <a href="{base}/glossary/feels-like">feels-like</a> metric and grades how unusual it is locally.
- slug: wind-chill
  term: Wind chill
  short: How cold it feels when wind is factored into the air temperature.
  body: |-
    <b>Wind chill</b> is the apparent temperature on a cold, windy day: wind strips away body heat, so it feels colder than the air temperature. It's the cold-weather half of <a href="{base}/glossary/feels-like">feels-like</a>.
- slug: humidity
  term: Absolute humidity
  short: The actual mass of water vapor in the air, in grams per cubic meter.
  body: |-
    Thermograph reports <b>absolute humidity</b> (g/m&sup3;), the real amount of water vapor in the air, rather than relative humidity, which shifts with temperature. Graded against local history, it shows genuinely muggy or unusually dry days.
- slug: reanalysis
  term: Reanalysis (ERA5)
  short: A gridded, physically-consistent record of past weather for anywhere on Earth.
  body: |-
    A <b>reanalysis</b> blends historical observations with a weather model to produce a consistent record of past conditions everywhere, even where no station exists. Thermograph's ~45-year history comes from ECMWF's <b>ERA5</b> reanalysis (via Open-Meteo), which is why it works for any point on Earth.
