Go to Home Page Glossary of terms
 
Term Explanation
Above Mean Sea Level (AMSL) Any height above the mean sea level. See: Mean Sea Level below.
All Time Records -
Record High Temperature
Highest temperature recorded during 1 day
All Time Records -
Warmest Day
Highest averaged temperature in a 12 hour period (6am - 6pm)
Aphel (aphelion) Farthest from the sun
Apogee Farthest from the earth
Barometer corrected to MSL Adjustment made to allow for the height the barometer is above MSL
Base 18 degrees/degree days How many days the temperature was below 18C (65F). See: http://www.energylens.com/articles/degree-days for a fuller explanation.
Cloud base Lowest level of visible cloud or the height at which clouds may form
Dew point The temperature point at which air is cooled causing water vapour to condense out into water
Dry bulb thermometer Ordinary thermometer. See: wet bulb thermometer below.
FSU buoys

These are instruments which collect weather and ocean data within the world's oceans. They measure such things as air temperature at the ocean surface, water temperature, wave height, dominant wave period, barometric pressure, wind speed (steady and gusting) and wind direction.

The buoys transmit this data via satellite communications to meteorological centres for use in weather forecasting and climate study. Both moored buoys and drifting buoys (drifting in the open ocean currents) are used. Data obtained from Florida State University (FSU).

Humidity The amount of water vapour in the air
Mean Sea Level (MSL) Mean sea level (MSL) is the average (mean) height of the sea, with reference to a suitable reference surface. Defining the reference level, however, involves complex measurement, and accurately determining MSL can prove difficult. See: Wikipedia explanation
METAR This is a world-wide recognised format for reporting weather information and is predominantly used by pilots as a part of a pre-flight weather briefing. It is also used by meteorologists who use it to assist in weather forecasting.
Moon – age How many days into the lunar phase, i.e. since last new moon
Moon – new Beginning of a new lunar phase (no moon visible with naked eye)
Moon – first quarter Half the moon is visible (right side if in northern hemisphere)
Moon – full Whole moon visible
Moon – last quarter Half the moon is visible (left side if in northern hemisphere)
Perigee Nearest to the earth
NOAA National Oceanic and Atmospheric Administration
Perihel (perihelion) Nearest to the sun
Precipitation The falling to earth of any form of water (rain, sleet, snow, mist or hail)

Temperature – apparent

What the temperature actually feels like taking into account temperature, wind and humidity, e.g. if it's windy it will feel colder than the measured air temperature.
UTC
(Coordinated Universal Time)
In casual terms GMT (Greenwich Mean Time) and UTC are considered the same.
Wet bulb thermometer A thermometer that has its bulb wrapped with a wet muslin covering. A wet bulb temperature will be lower than a dry bulb due to the effect evaporation. See: Wikipedia explanation
Windrun Product of wind speed and time. For example, if the wind had been blowing at 2 m.p.h. for 6 hours that would give a windrun value of 12 miles
Wind chill Cooling effect of exposed skin caused by the wind
 

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