Something I’ve noticed in weather reporting is that alongside the actual temp they’ll also announce a wind chill in winter. In summer it’s a heat index depending on humidity.
I can’t help wondering why wind chill isn’t also factored in during summer. (I know from experience it does feel cooler in a breeze even in summer. Likewise, why is humidity disregarded as a warming affect during winter?
Both are reported due to the way they affect the “feel” of ambiant temperature to humans.
There is a thin layer of static air that surrounds solid objects (like our bodies) that helps insulate us slightly from the ambient air temperature. When the wind picks up with sufficient strength it removes that insulating layer so that we feel the cold of the outer air more directly - wind chill.
Conversely, human bodies cool themselves by releasing moisture to the outter skin to be evaporated. Increased levels of humidity in the air reduce the amount of moisture that can evaporate from our skin, so that we feel not only the heat of the ambient air temperature, but also are stuck with the residual heat from our own bodies that we cannot get rid of.
It would have less meaning to report humidity in the cold as colder air can hold more moisture than warm air. It would mean less to report wind chill in hotter climates as it is the ambient humidity that is the limiting factor in our bodies’ ability to cool themselves.
djm
Don’t forget the temp “in the shade”.
Really, a unified “feeling” index using all criteria would be nice.
Not that I would use it. Just give me the temp., wind (speed AND direction), humidity (skip the due point), precipitation (% chance AND amount/type), and cloud cover.
Temp. I think it is about time we switch over to Kelven and get rid of this whole Below 0 nonsense.
Wind direction/speed. Windchill is nonsense. For windy days you can wear a thin jacket that doesn’t allow air to cut through that would be inappropriate for an equivalent temperature without wind. Give me the speed and direction so I know if I am biking to work with a head wind.
Precipitation. “50% chance of rain” Useless. It makes a difference to me if it is a light drizzle that lasts all day or a sleet filled down pour that lasts 30 minutes on my commute back home.
Cloud cover is nice to know, but not that important. On the radio put it first in the line up so that I know that the rest of the forecast is coming up, and keep the order consistent rather than mixing up order in which things are announced for “variety”.
I don’t care what they say, a humid, dark, cloudy, day at 32°F with a 45mph wind and lots of sleet does not “feel” the same as a 12°F calm sunny day.
I also like to know barometric pressure and pressure trends.
Windchill is nonsense. For windy days you can wear a thin jacket that doesn’t allow air to cut through that would be inappropriate for an equivalent temperature without wind. Give me the speed and direction so I know if I am biking to work with a head wind.
Around here, they don’t really start talking windchills until they are in the single or negative digits (today’s windchill is about -10 Farenheit). This is when windchill is important - not whether or not you’re going to be a little cold, but when you are risking life and limb - literally - by not dressing properly. That’s what I’ve always used windchill for.
Yup, when wind exposure for four or five minutes will be enough to cause permanent damage you want to be forewarned.
djm
More fun on the West Buttress of Denali on a “Spring” day with “slight” breeze brushing across yer cheek at 70mph while the temp is -35. Of course Augusta up in Eau Claire Co. can get nippy too.