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Definition: The probability of precipitation in a weather forecast is an estimate of the chance of a measurable amount of rain or snow falling anywhere in a given forecast region over the forecast period. Probabilities are given in 10 percent increments.

Ref: http://canadaonline.about.com/cs/weather/g/pop.htm

UNDERSTANDING POP (CHANCE OF PRECIPITATION)

POP is the probability of any particular point location within a forecast area receiving measurable precipitation in a given time period. POP is determined by two parameters: The probability that any precipitation will occur in forecast area AND predicted areal coverage of precipitation if precipitation does occur. Thus, areal coverage is just one aspect of POP. The chance that any measurable precipitation will occur in the first place within the forecast area must also be considered. When referring to POP it is most accurate to say, "There is a ___% POP that any particular measurement station in the viewing area will get precipitation". For example, when averaged over many 30% POP days, a particular station should have precipitation 30% of the time if the forecaster or computer model is accurate.

Suppose during the course of a year that a Dallas measurement station has a 30% POP on 100 individual days. If the POP prediction is fairly accurate over the long term, it should have precipitated at the Dallas station on about 30 of those days. Thus, think of POP in terms of a long term average prediction. All to often, people assume a 20% chance of rain means 20% of forecast area will get rain on that one day. This is often not the case for any one day. Often no precipitation occurs at all in the forecast area on days with a 20% POP since one component of POP is the chance that any precipitation will develop.

Ref: http://www.theweatherprediction.com/habyhints/284/

Probability of Precipitation

A Probability of Precipitation or POP is a formal measure of the likelihood of precipitation that is often published from weather forecasting models.

In U.S. weather forecasting, POP is the probability that more than 1/100th of an inch of precipitation will fall in a single spot, averaged over the forecast area.[1] For instance, if there is a 100% probability of rain covering one side of a city, and a 0% probability of rain on the other side of the city, the POP would be 50%. A 50% chance of a rainstorm covering the entire city would also lead to a POP of 50%.

Note that the POP measure is meaningless unless it is associated with a period of time. U.S. forecasts commonly use POP defined over 12-hour periods (POP12), though 6-hour periods (POP6) and other measures are also published.

The mathematical definition of Probability of Precipitation is defined as:

PoP = CxA[2]

C = the confidence that precipitation will occur somewhere in the forecast area.

A = the percent of the area that will receive measurable precipitation, if it occurs at all.

For example; a forecaster may be 40% confident that under the current weather conditions that precipitation will occur, and that should rain happen to occur it will happen over 80% of the area. This results in a PoP of 32% ((0.4x0.8)x100 = 32%)

Q: What is the Definition of precipitation chance?

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the definition of chance is to.... smd

There is a 10% chance of any form of water falling from the sky.

That out of 100%, there is a 15% chance of rain (if it helps think of it as 15 out of 100 points). So very unlikely it will rain

Quantitative data is data that measures quantity, as opposed to qualitative data which describes quality. Some examples of quantitative data pertaining to weather would be: measurements of precipitation, records of number of days per month without precipitation, percentage of the chance of precipitation, records of daily high temperatures.

the extent to which something is probable; the likelihood of something happening or being the case. the chance that something will happen the likelihood of an event occurring

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direct chance of precipitation increases and water droplet increases

Chance of precipitation is the likelihood of measurable precipitation (rain, snow, sleet, etc.) occurring within a specific area during a designated time period. It is usually expressed as a percentage, indicating the probability of encountering precipitation at a given location. For example, a 30% chance of precipitation means there is a 30% likelihood of measurable precipitation happening in that area.

the definition of chance is to.... smd

As relative humidity increases, the chance of precipitation also tends to increase. This is because higher relative humidity indicates that the air is closer to reaching its saturation point, and clouds are more likely to form and produce precipitation.

92 °F Chance of T-storms 40% chance of precipitation

0 percent precipitation means that there is no chance of any form of precipitation (rain, snow, sleet, etc.) occurring within the specified period of time and location.

There is no 100% CHANCE of anything - If it is 100% it is 100% - raining or snowing

Precip chance, short for precipitation chance, measures the likelihood of measurable precipitation occurring at a specific location within a given time frame. It is typically expressed as a percentage, where a higher percentage indicates a greater likelihood of precipitation.

The desert, by definition, is a region that receives little precipitation.

It is possible. Your best chance though is to pay attention to when that precipitation is expected to happen.

Chance of precipitation refers to the likelihood of any form of precipitation (such as rain, snow, sleet, or hail) occurring in a specific area. It is usually expressed as a percentage and is an estimation provided by weather forecasts on the probability of measurable precipitation happening in a given location during a specific time frame.

"The desert valley at that location normally received only about nine inches of precipitation a year.""The weather channel said that there was a 100% chance of precipitation."