How Cold I am, a weather math question

Factual Questions
1

I’m trying to make a math formula that would indicate how cold it is for someone surfing. There are some factors; but I don’t know what order to put them in:

  1. air temperature 2) wind chill factor 3) wet chill factor
  2. water temperature

Is there a way to formulate this? Here are some practice numbers close to reality. air temp= 55, water temp= 52, wind speed=15mph
thanks

2

Here are some links which may prove helpful (courtesy of dogpile.com):

http://www.usatoday.com/weather/wchilfor.htm
http://www.nsac.ns.ca/mp/mp100/modules/cases/newton/data/csdata3.htm
http://www.crh.noaa.gov/techpapers/arp19/19-07.html
http://www.woodrow.org/teachers/mi/1993/28stra.html

Have fun!

3

You might want to also consider releative humidity. On a dry day, the evaporation of water (if the surfer is not IN the water) is a substantial consumer of heat.

In the problem that you proposed, the fact that the water temperature is 52 degrees probably outweighs all other factors combined (and then some). I can easily stay outside today in 45 degree weather for about 15 minutes without any problem. I once was immersed in 58 degree water and I was in pain within 2 minutes.

4

bizerta, that’s because water takes heat from your body ten times as fast as air does. So, 2 minutes in the water =20 in air…brrrrr