It is a technical term used to measure rains by devices like rain gauge ! 1 cm of rain means the height of water (from the start to end ) that strike the ground level if measured in a standard container !
So 1mm rain means 1000mm length × 1000mm breath × 1mm height = 1litre of water. In laymen language: Take a vessel of 1 square meter in dimention and keep it in an open space during rain, you will be having 1mm height of water in it that is 1 litre of water in it at the end of the rain.
Rainfall intensity is measured in two ways, one is to collect rain water through a standard rain gauge and measure its height in millimeter after every one hour. Here,rain intensity is actually measured as millimeter in height,it is the height of the rain water column collected over a standard area.
How Much Rain Will Accumulate
| Terminology | Rainfall Rate |
|---|
| Very light | < 0.01 inch per hour |
| Light | 0.01 to 0.1 inch per hour |
| Moderate | 0.1 to 0.3 inches per hour |
| Heavy | >0.3 inches per hour |
Classically, rain was measured to know total amount of rain water fallen over an area in 24 hours. This was measured in inches and in MKS system,now it is millimeter. mm gives more accuracy as the height of the rain water multiplied by the area, gives total volume of water fallen in that area in 24 hours.
Rain is measured in units of length per unit time, typically in millimeters per hour, or in countries where imperial units are more common, inches per hour. The standard way of measuring rainfall or snowfall is the standard rain gauge, which can be found in 100-mm (4-in) plastic and 200-mm (8-in) metal varieties.
Most standard rain gauges have a wide funnel leading into the cylinder and are calibrated so that one-tenth of an inch of rain measures one inch when it collects inside. The funnel is 10 times the cross-sectional area of the tube. Rainfall as low as . 01 inches can be measured with this instrument.
What are the 6 Seasons in India?
- Spring Season- Vasant Ritu.
- Summer Season- Grishma Ritu.
- Monsoon Season- Varsha Ritu.
- Autumn Season- Sharad Ritu.
- Pre-winter Season- Hemant Ritu.
- Winter Season- Shishir or Shita Ritu.
Mawsynram (/ˈm?ːs?nˌr?m/) is a village in the East Khasi Hills district of Meghalaya state in north eastern India, 65 kilometres from Shillong. Mawsynram receives the highest rainfall in India and the World.
Monsoon or rainy season, lasting from June to September. The season is dominated by the humid southwest summer monsoon, which slowly sweeps across the country beginning in late May or early June. Monsoon rains begin to recede from North India at the beginning of October. South India typically receives more rainfall.
normal or average rainfall is the amount of precipitation that we expect per year (in a given area). it is obtained and set by calculating the average (mean) of precipitation recorded in an area during many years ( at least 30 years). Annual rainfall or precipitation is the sum of daily rainfall in a year.
These rains normally occur from March to April, although their arrival is often difficult to predict. Their intensity can range from light showers to heavy and persistent thunderstorms. In India, the mango showers occur as the result of thunderstorm development over the Bay of Bengal.
This winter has seen a lot of rainfall as well as snow in the Himalayas because of western disturbances. Another western disturbance is forecast to bring snow, rain and gusty winds in northern India from Wednesday. This winter has seen a lot of rainfall as well as snow in the Himalayas because of western disturbances.
10 mm rainfall means that if rainfall fell on a flat land surface , with no slope ,no evaporation, and no percolation of water I.e. water does not go underground, then the amount of rainfall would be 10 mm measured from the ground. Now this is practically not possible ,so ideally rain gauge is used to measure rainfall.
Weather forecasts are based on complex mathematical equations where the variables are determined through observations such as precipitation amount and intensity. So, precipitation measurement is important for weather forecasting. This is where we need other measuring instruments beyond rain gauges.
Precipitation (Weather) Precipitation in meteorology refers to all forms of liquid or solid water particles that form in the atmosphere and then fall to the earth's surface. Types of precipitation include hail, sleet, snow, rain, and drizzle.
Heavy rain: Greater than 4 mm per hour, but less than 8 mm per hour. Very heavy rain: Greater than 8 mm per hour. Slight shower: Less than 2 mm per hour. Moderate shower: Greater than 2 mm, but less than 10 mm per hour.
The first standardized rain gauge was invented in 1441 in Korea. In 1662 the first tipping bucket rain gauge was invented in Britain by Christopher Wren and Robert Hooke.
An inch of rain means that if you would catch the rain on a flat surface, it would reach up to an inch in height. To properly measure this, you need to make sure that the water can't flow away or dissipate into the ground, so you'd need a waterproof box with an open top for the rain to fall in.
The standard United States National Weather Service rain gauge, developed at the start of the 20th century, consists of an 8-inch diameter (203 mm) funnel emptying into a graduated cylinder, 1.17 inches (29.7 mm) in diameter, which fits inside a larger container that is 8 inches in diameter and 20 inches (508 mm) tall.
The gauge should be installed 2-5 feet above the ground mounted on the side of a single post. The top of the rain gauge should extend several inches above the top of the mounting post. The mounting post should have a rounded, pointed, or slanted top to avoid upward splash towards the rain gauge.
Average annual rainfall for a place is generally calculated by averaging the last 30-35 years of annual rainfall. Annual rainfall is the sum of daily rainfall, that can be calculated from raingauge records. Here, while calculating average annual rainfall one must take the length of period into account.
The 8-inch gauge used in the National Weather Service is of a standardized design used throughout the world for official rainfall measurements. The inner measuring tube of the large NWS gauge holds 2.0 inches of precipitation. The measuring tube of the small gauge holds 0.50 inch.
