Take that to mean the probability of occurrence is greater than 80 percent.Īrm yourself with the latest weather forecast before you launch on your next outdoor adventure this summer, then keep an eye on the sky to see how well those probabilities are panning out, I guarantee it will be different everyday. If no uncertain terms or probability numbers are used, then certainty is high, such as, “Thunderstorms today”, or “Showers this afternoon”. “Slight chance”, “Chance”, “Possible”, or “Likely” are all uncertain descriptive terms that can be used interchangeably for the percent probability in the text of the forecast. In other words, if the POP or thunderstorm probability is quite high, 70-percent or greater, that means the computer model, and/or the forecaster is highly certain about what will happen during the forecast time period, and the odds are good that the forecasted weather will materialize. What you should look for in the forecast before heading out the door for the day is how certain or uncertain the forecast sounds to you. In some cases, the local forecaster’s experience will get factored into the equation, as well. Nowadays, computer models generate the POP’s and chances for thunderstorms. You could also interpret that to mean that there is a 70-percent chance there won’t be any precipitation (or thunderstorms) where you are. 30 or 30-percent).Įither way, you should interpret a 30-percent chance to mean: there is a 30-percent chance precipitation (or thunderstorms) will occur at any given point within the forecast area. 30 or 30-percent chance).Ģ) There is only 30-percent confidence that precipitation will occur, but if it does occur, it will produce precipitation over 100-percent of the area. PoP = C x A where “C” = the Confidence that precipitation will occur somewhere in the forecast area, and where “A” = the Percent of the Area that will receive measureable precipitation, if it occurs at all.Ī “30-percent PoP” could be calculated one of two ways, as per these examples:ġ) There is 100-percent confidence that precipitation will occur, but only 30-percent of the area will get it.
The correct meteorological translation of “Probability of Precipitation” is: “The likelihood of occurrence of a measurable amount of precipitation (at least 0.01 inches) at any given point within the forecast area.” The same could be said for the probability of thunderstorms occurring.įrom the National Weather Service, PoP is defined mathematically as follows: Actually, neither of those is totally accurate. That is often interpreted to mean, “it is going to rain for 30-percent of the day”, or “30-percent of the area will get precipitation”. Most weather forecasts will provide you with a “probability of precipitation”, or PoP, which might say something like: “30-percent chance of showers today”. Maybe that will help you when planning your next outdoor activity. In this week’s column, I will give you some insight into how those forecasts are made, and what they really mean. And with any thunderstorm, it is implied that there could also be heavy downpours, and/or gusty winds, and/or hail involved. Nailing down where, when and how strong the thunderstorms might be is as difficult a task as deciding where, when and how much snow will fall in the winter season, throughout the Jackson Hole area.īy definition, if there is thunder, there is lightning. (Re-posted from original article that appeared in the Jackson Hole News & Guide’s Mountain Weather column, July 23, 2014).įrom where I sit, thunderstorm forecasting during the summer season is quite challenging, and on par with snowfall forecasting in the winter. MHRA 'POP', All Acronyms, 7 August 2022, Bluebook All Acronyms, POP (Aug. POP, All Acronyms, viewed August 7, 2022, MLA All Acronyms.
Retrieved August 7, 2022, from Chicago All Acronyms.
Facebook Twitter Linkedin Quote Copy APA All Acronyms.