24h graph 14day graph A barometer is commonly used for weather prediction, as high air pressure in a region indicates fair weather while low pressure indicates that storms are more likely. Simultaneous barometric readings from across a network of weather stations allow maps of air pressure to be produced. Isobars drawn on such a map links sites with the same pressure and give, in effect, a contour maps of areas of high and low pressure. Localized high atmospheric pressure acts as a barrier to approaching weather systems, diverting their course. Low atmospheric pressure, on the other hand, represents the path of least resistance for a weather system, making it more likely that low pressure will be associated with increased storm activities. If the barometer is falling then bad weather or some form of precipitation will fall, however if the barometer is rising then there will be nice weather or no precipitation. The past 12 months 24h graph 14day graph Temperature measurement using modern scientific thermometers and temperature scales goes back at least as far as the early 18th century, when Gabriel Fahrenheit adapted a thermometer (switching to mercury) and a scale both developed by Ole Christensen Røemer. Fahrenheit's scale is still in use, alongside the Celsius scale and the Kelvin scale. The world's average surface air temperature is 15 °C Vostok, Antarctica holds the lowest temperature record of -88 °C on 13 Sep 1922 The highest measured temperature on Earth is 57.8 °C in the desert of El Azizia, Libya on 21 Jul 1983 The past 12 months 24h graph 14day graph Absolute humidity refers to the mass of water in a particular volume of air. Absolute humidity is expressed as the number of kilograms of water vapor per cubic meter of air. Imagine a cube of air that is one meter wide, one meter high, and one meter deep. If we could "squeeze" all the water out of that cube of air into a container, we could weigh the container and see how many kilograms of water it contains. The amount of vapor in that cube of air is the absolute humidity of that cubic meter of air. Relative humidity is defined as the ratio of the partial pressure of water vapor in a gaseous mixture of air and water vapor to the saturated vapor pressure of water at a given temperature. That is, a ratio of how much energy has been used to free water from liquid to vapor form to how much energy is left. Relative humidity is expressed as a percentage The past 12 months 24h graph 14day graph Associated with humidity is dew point (if the dew point is below freezing, it is referred to as the frost point). Dew point as an absolute measure of the humidity and represents the temperature at which water vapor saturates from an air mass into liquid or solid usually forming rain, snow, frost, or dew. Dew point normally occurs when a mass of air has a relative humidity of 100%. This happens in the atmosphere as a result of cooling through a number of different processes. The past 12 months 24h graph (average wind) 14day graph (average wind) Wind is the rough horizontal movement of air (as opposed to an air current) caused by uneven heating of the Earth's surface. It occurs at all scales, from local breezes generated by heating of land surfaces and lasting tens of minutes to global winds resulting from solar heating of the Earth. The two major influences on the atmospheric circulation are the differential heating between the equator and the poles, and the rotation of the planet (Coriolis effect). Given a difference in barometric pressure between two air masses, a wind will arise between the two which tends to flow from the area of high pressure to the area of low pressure until the two air masses are at the same pressure, although these flows will be modified by the Coriolis effect in the extratropics. The all-time surface wind record is 103.3m/s. The place was Mt. Washington on 12 April 1934. The past 12 months 24h graph (gusts) 14day graph (gusts) About these wind graphs: Wind Speed (above) = the average wind, calculated over 10 minutes Hi Wind Speed = the peak wind speed (gusts) over the periode Wind Direction (below) = From were it's blowing (12 months graphs are not useful!) The past 12 months 24h graph (wind direction) 14day graph (wind direction) 24h graph 14day graph Precipitation (also known as hydrometeor) is any product of the condensation of atmospheric water vapor that is deposited on the earth's surface. It occurs when the atmosphere (being a large gaseous solution) becomes saturated with water vapor and the water condenses and falls out of solution (i.e., precipitates). Precipitation that reaches the surface of the earth can occur in many different forms, including rain, freezing rain, snow, sleet, and hail. Virga is precipitation that begins falling to the earth but dries up before it reaches the surface. Precipitation is a major component of the hydrologic cycle, and is responsible for depositing most of the fresh water on the planet. Approximately 505,000 km³ of water falls as precipitation each year, 398,000 km³ of it over the oceans. The world's place with the highest annual precipitation is Lloro, Colombia with approx. 13000mm/year. (Yes, 13-thousand!!) The place with lowest precipitation is the desert of Arica, Chile with only 0.7mm/year. Rain the past 12 months 24h graph (Rain rate) 14day graph (Rain Rate, max/day)   Rain rate the past 12 months 24h graph 14day graph Moisture content in wood affects both the size and strength of lumber. If you know the EMC of the storage or manufacturing area (which is derived using temperature and humidity readings), you can also determine the moisture content of the wood stored there. The past 12 months 24h graph 14day graph Air Density (the weight of 1 cubic foot or 1 cubic meter of air ) is a valuable tool for racing enthusiasts, because it helps determine the optimal jetting under current weather conditions. Internal combustion engines operate at their peak efficiency (producing the most power or using the least fuel) when the correct ratio of oxygen and fuel are introduced into the combustion chamber. The carburetor jets (or fuel injector setting) control the ratio of how much fuel is introduced into a given airflow. Carburetors do not automatically compensate for changes in the amount of oxygen in that airflow and therefore changes in oxygen concentrations can result in inefficient operation. Changes in the oxygen content of air result from changes in the weather (barometric pressure, temperature, and humidity). Measuring oxygen concentration in air is difficult; other measures are commonly used to estimate oxygen content. For example, determining changes in the density of the air (i.e., how much a given volume of air weighs) can produce a reasonable estimate of changes in oxygen concentration. One must develop "rules of thumb" to use air density effectively in tuning carburetors for optimal performance. One such rule of thumb is that a five percent (5%) change in air density may require re-adjustment of the carburetor jetting. High air density readings indicate more oxygen in the air, thus more fuel is needed (richer tune), while low readings indicate less oxygen, requiring less fuel (leaner tune). The past 12 months Perhaps not the most interesting section. ;) 24h graph 14day graph This section shows the temperature in my bedroom... The past 12 months 24h graph 14day graph This section shows the humidity in my bedroom... The past 12 months