The word humidity simply means the presence of water vapour in the air. It is found everywhere, even over great deserts. Due to water in atmosphere, we have clouds, fog, rain, snow and warm, sticky days. The instrument which is used to measure the amount of water vapour in the air is a hygrometer ( check for humidity sensors too - senses relative humidity over range from 0 to 95% ). The most accurate kind is called the wet and dry bulb hygrometer Two thermometers are mounted side by side on a base. The bulb of one is covered with muslin or some coarse material which is kept wet. The bulb of the other is left bare and dry. If the air contains much water vapour the moisture on the wet bulb evaporates slowly and the wet bulb thermometer does not show much lowering in temperature If the air is dry, the moisture on the wet bulb evaporates rapidly and the wet bulb thermometer shows a much lower temperature than the dry bulb thermometer. There are other types of hygrometers that use currents of air or chemicals or a hair to measure the increase or loss of moisture in the air .
Humidity Gauge - more information on Hydrometer - Types of hydrometer
Information comes with a weather forecast :
- current weather status - cloudy ,partially cloudy,sunny , rainy red hot ...
- Wind direction and speed : eg: N and 18 Kmph.
- weather humidity : like 71% or 86% etc..
- dew point , temperature and pressure .
Try this : Sydney weather forecast - sydney weather , Weather London ( 10 day weather forecast in london -with charts graphs ).
How Weather man forecast the weather for a particular area ?
In order to understand this we have to know what is weather. Weather is a condition of the air or the atmosphere at a particular place at any given time. No matter what the air is cold, cool, warm, hot, calm, breezy, windy, dry, moist or wet - that's weather. Weather changes from hour to hour, day to day, season to season and even from year to year .The weather forecasters observe changes very carefully. They know that the daily changes in weather are caused by storms and fair weather moving over the earth. They know that the seasonal changes are due to the turning of the earth around the sun. The most important "cause" of weather is the heating and cooling of the air. Heat causes the wind. As well as the different ways in which water vapour appears in the atmosphere. One of the ways the weather forecaster studies the weather is to look at the "fronts" that exist. Fronts are boundary lines between the cold air moving southwards from the north and the warm air moving from the tropics. Most of the severe storms which cause rain, snow and other types of weather are in some way related to these fronts. The weather forecaster when finds low pressure, he/she knows that storm is likely to occur because cold air is moving in to replace warm rising air that is laden with moisture. High pressure indicates fair weather. The weather forecaster forecasts on the basis of certain facts about weather and on the basis of the reports of the weather in most parts of the country.
Check this for Weather Forecast for Popular cities in India - weather forecast for Popular Indian cities .
Different Types of Weather pictures
Windy Weather condition
Credit : dropgrabs
Weather - Sunny Beach side - Clear Clouds
Weather partly Cloudy
