Apparent Temperature - The apparent temperature (or heat index) is a measure of relative discomfort due to combined heat and high humidity. It was developed by R.G. Steadman (1979) and is based on physiological studies of evaporative skin cooling for various combinations of ambient temperature and humidity. The apparent temperature equals the actual air temperature when the dew-point temperature is 57.2F (14C). At higher dew points, the apparent temperature exceeds the actual temperature and measures the increased physiological heat stress and discomfort associated with higher than comfortable humidities. When the dew point is less than 57.2F, on the other hand, the apparent temperature is less than the actual air temperature and measures the reduced stress and increased comfort associated with lower humidities and greater evaporative skin cooling.

Barometric Pressure - The air that makes up our atmosphere exerts a pressure on the surface of the earth. This pressure is known as atmospheric pressure. Generally, the more air above an area, the higher the atmospheric pressure. This, in turn, means that atmospheric pressure changes with altitude. For example, atmospheric pressure is greater at sea-level than on a mountaintop. To compensate for this difference in pressure at different elevations, and to facilitate comparison between locations with different altitudes, meteorologists adjust atmospheric pressure so that it reflects what the pressure would be if measured at sea-level. This adjusted pressure is known as relative barometric pressure. Barometric pressure changes with local weather conditions, making barometric pressure an important and useful weather forecasting tool. High pressure zones are generally associated with fair weather, while low pressure zones are generally associated with poor weather. For forecasting purposes, the absolute barometric pressure value is generally less important than the change in barometric pressure. In general, rising pressure indicates improving weather conditions, while falling pressure indicates deteriorating weather conditions.

Beaufort Wind Scale - The Beaufort Wind Scale is a numeric scale from zero to twelve used to measure wind speeds in knots. Meteroligists use the scale to assign terms to the current or future wind conditions ranging from calm to hurricane.

Cloud height - The cloud height is an estimate based on the Dew Point, which is based on the humidity and temperature from the station. And it is based on an assumed adiabatic environmental elapse rate....(dry air assumption). So the height at which the temperature reaches the Dew Point due to cooling as altitude increases, is the estimated cloud height. By knowing the altitude of the station, this then creates an offset for the cloud height formula. The formula is simply the Dew Point depression times 412 (estimated cloud height in feet).

Dew Point - Dewpoint is the temperature to which air must be cooled for saturation (100% relative humidity) to occur. The dewpoint is an important measurement used to predict the formation of dew, frost, and fog. If dewpoint and temperature are close together in the late afternoon when the air begins to turn colder, fog is likely during the night. Dewpoint is also a good indicator of the air’s actual water vapor content, unlike relative humidity, which takes the air’s temperature into account. High dewpoint indicates high vapor content; low dewpoint indicates low vapor content. In addition a high dewpoint indicates a better chance of rain and severe thunderstorms. You can even use dewpoint to predict the minimum overnight temperature. Provided no fronts or other weather pattern changes are expected overnight , the afternoon’s dewpoint gives you an idea of what minimum temperature to expect overnight, since the air is not likely to get colder than the dewpoint anytime during the night.

METAR - Acroymn for METeorological Aerodrome Report. It is the primary observation code used in the United States to satisfy requirements for reporting surface meteorological data. Minimum reporting requirments includes wind, visibility, runway visual range, present weather, sky condition, temperature, dew point, and altimeter setting.

Wind Chill - The wind chill temperature is how cold people and animals feel when outside. Wind chill is based on the rate of heat loss from exposed skin caused by wind and cold. As the wind increases, it draws heat from the body, driving down skin temperature and eventually the internal body temperature. Therefore, the wind makes it FEEL much colder. If the temperature is 0 degrees Fahrenheit and the wind is blowing at 15 mph, the wind chill is -19 degrees Fahrenheit. At this wind chill temperature, exposed skin can freeze in 30 minutes.