- What is the formula to convert Fahrenheit to Celsius and vice-versa?
- Is there a formula to convert the barometric preasure given in inches of Hg to Millibars and vice versa?
- Is there a reasonably simple formula that is used to calculate wind chill?
- How does one calculate the heat index, given the relative humidity and the temperature?
- What is the dew point?
- If one knows the temperature and relative humidity (often given in weather forecasts), how can one calculate the dew point (often not given in weather reports)?
- What is the formula to convert dew point and ambient temperature to relative humidity?
- What is an ice fog and what conditions are necessary for such an event to take place? Are they common?
- If a trough is an elongated area of low pressure, then what is a front?
- Is there a difference between the "normal" daily high (and low) temperature and the "average" daily high (and low) temperature?
- I saw your weather site on the WWW and was wondering if you could help me find the cities with the most days of rain ( Most frequent rainfall vs rain volume)?
- Could you give me some information about the "pineapple connection."
- How does a cutoff low form?
- Does the old saying about red skies at night or morning actually have any scientific basis?
- I do not understand jetstreams...
- Why is the sky blue?
- Please explain the weather conditions required to produce fog.
- What's the chance that solar radiation interacting with the earths magnetosphere is a cause of the el nino/la nina phenomena?

**What is the formula to convert Fahrenheit to Celsius and vice-versa?**

C = 5/9 (F - 32)

Temperature Converter

**Is there a formula to convert the barometric preasure given in inches of Hg to Millibars and vice versa?**

**Is there a reasonably simple formula that is used to calculate wind chill?**

**V**) and the temperature in deg. Fahrenheit (

**T**) are known (SQRT = square root):

**TWC=91.4-((91.4-T)*(.478+(.301*SQRT(V))-.02*V))**

(NOTE: AT WIND SPEEDS OF 4 MPH OR LESS, TWC IS THE SAME AS THE ACTUAL AIR TEMPERATURE).

A table is also available to help determine the wind chill factor.

**How does one calculate the heat index, given the relative humidity and the temperature? **

**Heat Index= -42.379 + 2.04901523(T) + 10.14333127(RH) - 0.22475541(T)(RH) - 6.83783x(10 to the -3rd power)x(T to the 2nd power) - 5.481717x(10 to the -2nd power)x(RH to the 2nd power) + 1.22874x(10 to the -3rd power)x(T to the 2nd power)(RH) + 8.5282x(10 to the -4th power)x(T)x(RH to the 2nd power) - 1.99x(10 to the -6th power)x(T to the 2nd power)x(RH to the 2nd power).**where

**RH**is Relative Humidity and

**T**is temperature in deg. Fahrenheit.

A table is also available to help determine the heat index.

**What is the dew point?**

The Dew point cannot be more than the air temperature, and is usually much lower. At the earth's surface, the pressure varies only slightly, so the dew point is a good indicator of the moisture content of the air, as well as a good indicator of the level of human discomfort in warm, humid weather. For example, most people begin to feel uncomfortable when the dew point rises above 20 deg C/70 deg F. In contrast to the dew point, the relative humidity reading, which used to be presented in weathercasts so often, depends as much upon the temperature of the air as it does upon its moisture content. On a sunny day, the relative humidity may drop as much as 50% from morning to afternoon just because of the rise in air temperature, but the dew point would rise along with the temperature, giving a more accurate view of the discomfort level.

**If one knows the temperature and relative humidity (often given in weather forecasts), how can one calculate the dew point (often not given in weather reports)?**

**Td = (-430.22 + 237.7 * ln(E)) / (-ln(E) + 19.08)**

Where

**Td**is the dew point temperature in degrees Celsius, and

**E**is the actual vapor pressure of the air.

To start with, you should translate the current air temperature from Fahrenheit to Celsius, using the above noted formula. You then must determine the saturation vapor pressure

**(Es)**as shown on this table. Using that number, then determine the actual vapor pressure

**E**with the following formula:

**E = (RH * Es) / 100**

Plug the value of

**E**into the formula (note: ln(E) means take the natural log of E) and the result will be the dew point temperature in degrees Celsius. Use the above noted formula to convert back to Farenheit.

**What is the formula to convert dew point and ambient temperature to relative humidity?**

**RH = (E/Es) * 100**

Where

**E**is the actual vapor pressure, and

**Es**is the saturation vapor pressure of the air.

To start with, you should translate the current air temperature

**T**and dew point

**Td**from Fahrenheit to Celsius, using the above noted formula. You then must determine the saturation vapor pressure using the following formula:

**Es = 6.11 * (10.0 to the power of (7.5*T/(237.7+T)))**

Then determine the actual vapor pressure with the following formula:

**E = 6.11 * (10.0 to the power of (7.5*Td/(237.7+Td)))**

Plug the values of

**E**and

**Es**into the formula and the result will be the relative humidity.

**What is an ice fog and what conditions are necessary for such an event to take place? Are they common?**

**I have a question regarding fronts and troughs. If a trough is an elongated area of low pressure, then what is a front? Because a front has a narrow transition zone represented by the blue line or red line...but where the cold or warm front lies, is that the area of lowest pressure?**

**Is there a difference between the "normal" daily high (and low) temperature and the "average" daily high (and low) temperature?**

**I saw your weather site on the WWW and was wondering if you could help me find the cities with the most days of rain ( Most frequent rainfall vs rain volume)?**

**Could you give me some information about the "pineapple connection."**

**How does a cut off low form?**

**Does the old saying about red skies at night or morning actually have any scientific basis?**

*Red sky in morning, sailor take warning -*

Red sky at night, sailor's delight

Red sky at night, sailor's delight

**I do not understand jetstreams. The weather maps make it look lika a narrow column of hi speed wind? If so, how does it sustain itself without the surrounding air slowing it down? How wide is a jet stream?**

**Why is the sky blue?**

Light, which appears "white" to us, is actually made up of all the colors of the rainbow, each with its own unique wavelength. The purple and blue colors in the spectrum have the shortest wavelengths, with the oranges and reds having the longest. Light also always follows a straight path until forced otherwise by something. Air molecules are an example of such a "something" - they are just the right size to separate and redirect the short wavelength of blue along new paths.

So, as the "white" light enters the atmosphere from the sun, the blue light waves are scattered by air molecules all over the sky, making it the dominant color light you see no matter what direction you look in the sky.

Clouds are made up of more than just air molecules, of course, and the water and ice crystals found within clouds are capable of scattering all wavelengths, which combine to create the color "white". Dark clouds are simply those thick enough to allow little light through, or those in the shadow of other clouds or of the top of their own cloud.

**Please explain the weather conditions required to produce fog. What temp, dew point and/or relative humidity is required? I am most interested in the fog that forms at Nantucket, Mass.**

**What's the chance that solar radiation interacting with the earths magnetosphere is a cause of the el nino/la nina phenomena? Is there a correlation between years of high solar activity and the occurences of the el nino?**

If there is a connection it isn't an obvious one. El Ninos, including strong El Ninos have happened with both quiet and active suns. This year for example in what may be the strongest El Nino on record, the sun is just coming out of the minimum phase.

The solar activity in conjunction with other factors like the QBO has been shown to correlate with weather features thus indicating the solar activity has an effect on our atmosphere.