Locate scale and magnitude of fog, haze, smoke, snowfall, rain, etc. Snow covered areas tend to be lower in temperature. Often record lows occur on snow-covered nights with light winds and clear skies. Lake effect snow favored regions. Higher PW indicates regions where there is a larger depth of moisture and higher moisture content.
Warm air can evaporate exponentially more water than can cold air.
Atmosphere will become more unstable through moisture advection and low level warm air advection.