Normand's theorem

{
  "id": "MLC-T-MET-007602",
  "term": "Normand's theorem",
  "field": "Meteorology and atmospheric science",
  "definition": "A thermodynamic relationship that connects the wet-bulb temperature, the dew point temperature, and the lifting condensation level (LCL) on a tephigram or skew-T log-P diagram. It states that the dry adiabat through the LCL, the moist adiabat through the wet-bulb temperature, and the constant mixing ratio line through the dew point temperature all intersect at a single point. This theorem provides a graphical method for determining one of these values if the other two are known.",
  "url": "https://mlchart.com/terminology/meteorology/normand-s-theorem/"
}