in weather reports - what are the factors used and the formula to determine the RELATIVE HUMIDITY?

Question

I'm sure temperature and dew point play a part. But how, I'm looking for: x+y+z=relative humidity, where x,y, and z are unknown to me.

Answer 1

RH = (mixing ratio)/(saturation mixing ratio) * 100%

Basically relative humidity is a measure of the amount of moisture in the air relative to saturation, rather than the absolute amount of moisture in the air. The mixing ratio is the number of grams of water per 1 kilogram of dry air. This is the best way to find realtive humidity. The conversion using dewpoint is really ugly involving vapor pressure and gross exponents. If you're given a dewpoint, it's usually best to use a chart to find the relative humidity. You can find such a chart at http://www.lamtec.com/dew-point-calculator.htm If you are given a temp and a dewpoint, you can work backwards to find the relative humidity.

Answer 2

Rain, Snow, Sleet and Freezing Rain play a huge factor on the Relative Humidity. Usually if any kind of percepitation is falling from the sky, the Relative Humidity is about 90 to 100 percent. If its 90-100 percent and no percepitatioin is falling then, it will soon. Relative Humidity (%) cant be 30 percent and rain because even though its raining in the upper atmosphere, by the time it hits land, it would evaporate. So0o when you see a relative humidity go from 30 % to 50%, those can be easy signs that percepitation of some sort is going to fall. Remember the higher the relative humidity is, the higher the moisture is IN THE AIR (not skin) Moisture on the skin is a different term called Dew Point.

Answer 3

If for example the temperature was 6°C and the dewpoint was 4°C, the relative humidity would be around 90%. In a stable airmass, the temperature will generally not fall below the dewpoint at night. If it does, you will get dew or frost forming along with fog patches. A drop of 10°C would be the result of a changing airmass would may have different properties such a changing dewpoint, wind speed, etc.

Answer 4

Relative humidity is where you ask your brother to repay the $300 you loaned him and he says "Piss on you." That is relative humidity. Sorry, I just couldn't help it.