I know that's dumb, but I don't get it. @80(
2007-03-29 02:33:49 · 8 answers · asked by Dovey 7 in Science & Mathematics ➔ Weather
Ok - don't feel dumb. This is a fair question. When you are told the humidity is 100%, this is the relative humidity at the earth's surface, where you are. Under these conditions fog is most likely occuring because the air cannot hold any more water vapor and liquid drops are beginning to condense. Why isn't there any rain? Well it's because higher up in the atmosphere, the humidity is much lower. Both the temperature and the dewpoint temperature change with altitude which means the humidity changes with altitude. It is only when there is a convergence of warm, moist, and unstable air that can grow vertically that humidities aloft can reach 100%, and rain drops can form. Hope this helps explain this phenomena.
2007-03-29 02:42:25 · answer #1 · answered by 1ofSelby's 6 · 3⤊ 0⤋
Temperature is part of the calculation for relative humidity. As the temperature falls, the relative humidity rises. Every mass of air has a dewpoint - the temperature at which the rate of evaporation and the rate of condensation are the same. If the air is cooled to the dewpoint - as it often is at dawn - the relative humidity is 100%. Should the temperature fall below the dewpoint, water vapour condenses into dew, fog or frost but the relative humidity stays at 100%.
When air rises it cools. Again when the temperature falls below the dewpoint water vapour condenses into minute water droplets that we call cloud.
2007-03-29 04:50:44 · answer #2 · answered by tentofield 7 · 1⤊ 0⤋
Even if the air contains 100 percent humidity, it does not mean rain shoud occur.Water vapour shoud become water droplets.That means condensation which is the process of change of state of matter from vapour to liquid , shoud occur.Condensation nuclei are required for this to happen in the atmosphere.The atmosphere usually has sufficient condensation nuclei.Hence in the presence of condensation nuclei, water vapour shoud become water droplets before rain starts falling.
Condensation can take place in the atmosphere even when the relative humidity is as low as 70 percent provided the condensation nuclei are abundant.
2007-03-29 03:31:52 · answer #3 · answered by Arasan 7 · 1⤊ 0⤋
It just says that no more water can eavaporate into the air. It doesn't mean it has to be raining. If a cup is 100% full, it doesn't mean water is pouring over the side.
2007-03-29 03:49:24 · answer #4 · answered by Gene 7 · 1⤊ 0⤋
Its not dumb. You just dont understand it. The humidity can be 100 percent when its foggy.
2007-03-29 04:34:23 · answer #5 · answered by Justin 6 · 1⤊ 0⤋
Easy here in Houston, TX. Its ALWAYS 100% over the ending of Spring thru the begginning of Fall. But its also due to the fact that we have the gulf bringing in the moisture. If you live next to an ocean it my be why. Othere that that I don't know.
2007-03-29 02:43:08 · answer #6 · answered by a_newlinuxguy 2 · 1⤊ 0⤋
Think of mist or a dense fog. That's 100% as well.
2007-03-29 02:37:41 · answer #7 · answered by Leah 1 · 2⤊ 0⤋
It can here in iowa
2007-03-29 02:41:01 · answer #8 · answered by Invisible Pink RN 7 · 1⤊ 0⤋