what is the meaning of dewpoint in a weather forecast?

Answer 1

It is the temperature at which the air is 100% saturated with water vapor, ie. 100% relative humidity. The amount of water that air can contain goes up with temperature. If the dewpoint is 70 in the morning when the temp. is 70, the relative humidity will be 100%. In the afternoon if the dewpoint stays the same and the temperature goes up to 100, the relative humidity will go down because the air could hold more water than before.

Answer 2

If we cool air without changing its moisture content, eventually we'll reach a temperature at which the air can no longer hold the moisture it contains. Then water will have to condense out of the air, forming dew or fog. The dewpoint is this critical temperature at which condensation occurs.

The dewpoint is a measure of how moist the air mass itself is; that's why the Weather Channel's new dewpoint maps show us the movement of moist air masses across the country. Ordinarily the dewpoint doesn't vary much during a 24-hour period. Unlike temperature and unlike relative humidity, the dewpoint is usually the same at night as it is the daytime.

Answer 3

The dew point or dewpoint of a given parcel of air is the temperature to which the parcel must be cooled, at constant barometric pressure, for the water vapor component to condense into water, called dew. When the dew point temperature falls below freezing it is called the frost point, instead creating frost or hoarfrost by deposition.

The graph to the right shows the maximum percentage of water vapor that can exist in air at sea level across a range of temperatures. Note that with higher temperatures the equilibrium partial pressure of water vapor increases thus more water evaporates. The behavior of water vapor does not depend on the presence of air. The formation of dew would occur at the dew point even if the only gas present were water vapor.

The dew point is associated with the relative humidity. A high relative humidity indicates that the dew point is closer to the current air temperature. If the relative humidity is 100%, the dew point will be equal to the current temperature. Given a constant dew point, when the temperature increases the relative humidity will decrease. It is for this reason that equatorial climates can have low relative humidity yet still feel uncomfortable.

Hope you understand this.

Answer 4

OhioKate is right. But, it also tells us, most of the time, how cool it will get at night. As it's easier for air to change temperature the drier it is, as it approaches the dewpoint at night it begins to slow down. That's how, especially in winter, you'll notice the dewpoint and predicted low temperatures are closely related. Sometimes this is not true though.

Answer 5

dewpoint is just another way to tell how much watter vapor is in the air. it is the most direct way to tell this. dewpoints are not part of the forcast. they are given as observation. in general a dewpoint of 70degrees or higher is very uncomfortable. 60 degrees up is somewhat uncomfortable. 50 or higher is a bit uncomfortable. any dewpoint of less than 50 is rather dry air.

Answer 6

The dewpoint is the temperature at which dew will form. The closer to the dewpoint the air temperature is, the more humid it will be.

Answer 7

The temperature at which water vapor condenses into dew. Dewpoint increases as atmospheric humidity increases.

Answer 8

The temperature at which the humidity reaches 100% and dew condenses on surfaces.

Answer 9

The temperature, if the humidity remained the same, and the pressure, at which moisture would just begin to condense on solid surfaces.

Answer 10

It's the temperature at which water condensates.