So roughly, you’ll expect to lose at least 17.5 degrees. So, since you’re gaining 5,000 feet in elevation, you’ll use a 5 in your calculation. If you start out at 1000 feet, and climb to 6000 feet, that’s a 5000 foot difference (6000 – 1000 = 5000). Some people use 9.8 degrees Celsius per 1000 meters). You can also use about 1.2 degrees Celsius per ever 1000 feet, or about 1 degree Celsius per 100 meters (source, NFW who showed me my typo on the metric conversion in the comments). You will lose an average 3.5 degrees Fahrenheit for every 1000 feet of elevation you gain. A quick Google with “Mountain (Name) elevation” will normally get you what you need. Reference your topo map, or find these details online. Now you need to know how high up you are going to climb or descend. Here, we’re at 2,000 feet, and our forecast are all for 2,000 feet. If that information isn’t available, it’s usually the same elevation as your official city elevation. Using the National Weather Service website you can a detailed forecast, and they’ll list the elevation of reference on the page. Determine the elevation of reference for the forecast.Īll weather forecasts are referenced to a particular elevation.Look up the local area forecast, and see what the high, and low temperatures are going to be. Again, these are both simplified calculations designed to be done on the fly, they’re not exact. Also, if you do the math using Celcius vs Fahrenheit, you will get slightly different values. They’re not exact, they’re not terribly scientific, and they’re not meant to be used in such a way. Now, before we proceed, these are simple approximations. Here are the steps involved, and a simple equation to reference. Have you ever set off on a warm summer hike to find the temps at the peak in the 50’s or worse?Īvoid these surprises by knowing how to calculate the temperature loss as you climb. Significant deviations from these will result in heat index values which do not accurately reflect the perceived temperature.It’s no secret that the temperatures high up in the mountains will be lower than that in the valleys. Like the wind chill index, the heat index contains assumptions about the human body mass and height, clothing, and the wind speed. The heat index is derived from work carried out by R. Measurements have been taken based on subjective descriptions of how hot subjects feel for a given temperature and humidity, allowing an index to be made which corresponds a temperature and humidity combination to a higher temperature in dry air. However, when the relative humidity is high the evaporation rate is reduced, so heat is removed from the body at a lower rate causing it to retain more heat than it would in dry air. The human body normally cools itself by perspiration, or sweating, which evaporates and carries heat away from the body. The heat index (HI) is an index that combines air temperature and dew point in an attempt to determine the human-perceived equivalent temperature - how hot it feels, termed the felt air temperature. In cases where the apparent temperature is higher than the air temperature, the heat index is used instead. The wind chill temperature (often popularly called the wind chill factor) is always lower than the air temperature, except at higher temperatures where wind chill is considered less important. Wind chill is the apparent temperature felt on exposed skin, which is a function of the air temperature and wind speed. The combination of the heat index and the wind chill factor are denoted collectively by the single terms apparent temperature or relative outdoor temperature or simply Feels Like. Feels Like Index is a factored mixture of the Wind Chill Factor and the Heat Index. The Feels Like Temperatures map show what the outdoor temperature will feel like for the current day. Think of it this way:ġ) if it's freezing cold outside, the wind will make if seem even colder because any body heat you have will be blown away quickly.Ģ) if it's hot outside, high humidity will make it seem even hotter because your sweat won't easily evaporate. The "feels like" value is calculated based on temperature, but altered depending on wind (cold temperatures) or humidity (hot temperatures).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |