when air reaches the dew  point what is it called?
924607
fog. i guess.\n\n\n\nand what is trace?
1106348
"There are basically four elements of weather that can help describe weather. The four elements include  wind, temperature, air pressure and moisture." (From the ref.) These may seem an arbitrary choice until you realize that they are all easily measurable and independent of each other, whereas dew point and cloud cover can be said to derive from humidity, temperature and pressure.
997634
Dew results when water condenses out of the air as a liquid. Dew is liquid water.\n\nWhite frost resutls when water condenses out of the air direstly as ice crystals. White frost is solid water, AKA ice.\n\nBlack frost results from dew freezing. Unlike white frost black frost exists initially as water and then freezes, wheras white frost never exists in liquid form.
1115854
The weight of the air pressing down on the Earth, the ocean and on the air below causes air pressure. Earth's gravity, of course, causes the downward force that we know as "weight." Since the pressure depends upon the amount of air above the point where you're measuring the pressure, the pressure decreases as you go higher.\n\nso im guessing he talked about how in mountains, atmospheric pressure is low and high in deserts with regards to elevation. as air goes down/descends, it warms and cools as it goes up. \n\nhttp://www.usatoday.com/weather/tg/whighlow/whighlow.htm\n\nyes. froggie is right. the phenomenon is called rainshadow effect. \n\nnow i dont really know what your question is, but just a trivia. notice that on one side of tall mountain, it is high in plant life while the other is mainly desert? this is because the mountain blocks the moving air and forces it to precipitate thus causing rain which in turn supports lots of plants which support the animals.  now since the water molecules in the air was already precipitated/ let go on the one side, there is nothing left for the other side of the mountain thus the formation of deserts. so instead of formation of rain, the air starts to gather water molecules from its surroundings, depriving the plants of necessary moisture thus no plant life can be observed in most deserts. \n\nhope that helps.
786378
evaporation is when the liquid form of water eevaporates or becomes water vapor. evaporation is one part of the water cycle and is a very large one. evaporation puts water into the air as a gas called water vapor. this then condenses into tiny droplets, forming clouds. \n\nhope this helps
620707
As air gets warmer it's able to contain more water vapor.  An easy way to illustrate this is in a steamy kitchen or bathroom where you'll see that condensation forms on the coldest surfaces such as windows, mirrors, tiles etc.\n\nWhen the amount of water vapor in the air reaches it's maximum point the air is described as being saturated (saturation vapor pressure or SVP for short).  SVP is therefore reached more quickly when the air is cooler.\n\nWhen air reaches SVP it has to deposit the excess moisture which it does as dew or condensation and the point at which this occurs is called the dew point.  The colder the temperature the lower the dew point which helps explains the cool mornings when there's dew on the grass.\n\nHumidity is a measure of the amount of water vapor that's present in the air and is measured as a percentage of the maximum possible.  So a Relative Humidity (or RH) or say 60%, means that the air contains 60% of the maximum possible water vapor.  As mentioned, the amount of water vapor possible increases with temperature and so RH is affected by temperature.  An RH of 80% in a hot tropical climate is going to feel much damper and humid than an RH of 80% in a cooler climate.
1149937
Dew is water in the form of droplets that appears on thin, exposed objects in the morning or evening. As the exposed surface cools by radiating its heat to the sky, the rate at which atmospheric moisture evaporates from the surface drops below that at which it condenses on the surface from the air, so that droplets are formed.\n\nWhen temperatures are low enough dew takes the form of ice; this form is called frost.
800910
Typically between -20 and +10 degrees Celcius (-4 to +50 F). It depends very much on the amount of humidity in the air. If it is very humid you will start see it at higher temperatures than usual. That's because the air can only contain a certain amount of water vapour at a certain temperature and when the amount of water vapour increases that value the water will condense into liquid water and that's what you see when you "see you breath". The temperature you are referring to is called the dew point and can be found in advanced weather forecasts.
10778
A Psychrometer is the general name for instruments designed to determine the moisture content of air. A psychrometer consists of dry-and wet-bulb thermometers that give the Dry-and Wet-bulb Temperatures, which in turn are used to determine Relative Humidity and Dew Point.
45731
when there is a low pressure system that brings all the air towards it
404328
For clouds to form the air has to be unstable, meaning that the air at the surface is warmer than the air above. Remember the saying warm air rises? So when the air rises it hits a level called the Lifting Condensation Level or LCL. If the air rises to this point it then can start to condense on particles in the sky forming clouds.
652464
I think you mean water saturation point, right?  If so, that's the dew point.
143492
to my knowledge, it means mist or dew
169043
for frost you need cold and humidity.\n\nby looking at the dew point and temperture you can tell what is going to happen.  if the windshield temperature lowers to the dew point condensation will happen.  if it's above freezing then dew will form but if it's below freezing it will condense as frost.  but if the windshield temperature doesn't lower to the dew point no condensation will happen which is why some nights you don't get any frost at all.
80699
They're called contrails, short for condensation trails. When a jet engine is running it heats up the air traveling through it.  On the ground it's not that noticeable.  Up in the atmosphere where jets fly, the temperature is way below freezing. The warm moist air condenses as it exits the jet engines and you can see the water vapor the same way you can see your breath on a cold day.
634472
there are many ways of representing water vapor content in the air.  But relative humidity is the best one.  It can go past 100% up to 300% for very small droplets (this is called super saturation).  Now we can have the mixing ration which is the mass of the water vapor in the air/mass of the dry air, and it gives us units of g/kg... then we have dew point temperature, wetbulb tempearture... trust me we have a surplus of ways to measure water vapor in the air
22072
Clouds aren't just random droplets of water. What they are is tiny droplets of water that have condensed from water vapor in areas where the conditions (temperature, air pressure and humidity) are exactly right. Anywhere where you have the correct combination of these conditions, you'll get a cloud. Anywhere that you don't, you don't.\n\nAreas with this kind of conditions don't occur in random tiny places. Instead, there will be a large area of one condition that gradually shifts into another. (If this doesn't make sense, think of just temperature. You don't get a different temperature at every spot on the globe. Instead, you get a large area of warm air that gradually shifts into a large area of cooler air. The same is true for air pressure and humidity.) This is why you get a large area of 'cloud' in one place and nothing at all in another. You can think of clouds as being physical maps of the weather conditions in the sky.\n\nThis is also what holds the clouds up. In general, if a cloud is high up in the sky, the conditions just below it aren't right for the cloud to form. As the water droplets fall, they reach areas with the wrong temperature or pressure and evaporate again. Only if the clouds become densely packed enough for the water to form large enough droplets can the droplets fall to the ground. Not all clouds form high up, either... sometimes the right conditions can occur at groundlevel, giving us fog.