A Chance of Rain: What Does This Really Mean?
If you heard an “80% chance of rain,” would you assume that this meant that you had an 80% chance of getting rained on? Not true. Bob Berman explains what a “chance of rain” really means! If you’re a sky watcher like yours truly, the first step in observing the sky is having decent weather. We probably all check the forecast from time to time. But relatively few of us know how to make sense of it. Many of us would assume that an ”80% chance of rain’ means you have an 80% chance of getting rained on. This sounds logical but is incorrect. Guess again. Does it mean that there’s a chance of rain across 80% of the forecasted area? Nope. That’s because weather forecasts give their “percentage chance” in probabilities. The answer? An “80% chance of rain” means that there is an 80% chance that rain will fall somewhere within the forecasted area. Rain refers to 0.01 inch or more. Confused? If you want to understand this further, read on. How to Calculate a Chance of Rain So let’s say the forecast goes like this: Sunday, 40% chance of rain; Sunday night, 40% chance of rain; Monday, 40% chance of rain. Now maybe you’re a gardener and really want it to rain (consider catching the rain by using rain barrels in your garden!). Or, perhaps you have a stargazing session or outdoor event planned and desperately want it NOT to rain. The question is simple: If the Weather Service’s forecasts are accurate, then what are the chances that it will rain sometime during the period? What do you think? With a 40% chance tomorrow, tomorrow night, and then again the next day, what’s the likelihood we’ll get rain any time during that entire time span? Here’s how you calculate it. Stick with me for a few minutes. This is fun, as long as you don’t totally hate math. First, you determine the odds that it won’t rain. In this case, it’s 60% for each of the three periods in question.
So, you grab your calculator and punch in 0.6 x 0.6 x 0.6, and this equals 0.216. Bingo: those are the odds that it will not rain during the entire three periods in question. It is 21.6%. Finally, you subtract this from one to get the chance that it will rain: 78.4%. Roughly speaking, there’s an 80% chance it will rain. Amazing, right? Let’s do another for practice. Say the Weather Service predicts only a 30% chance of rain or snow today, and again tonight and again tomorrow. First, you determine the odds that it won’t rain. In this case, it’s 70% for each of the three periods in question. Now you multiply 0.7 x 0.7 x 0.7, which equals 0.343, which means a 34% percent chance of no precipitation falling. Thus, a 66% chance that it will rain or snow during the period. If this sounds illogical and you’re unconvinced, consider that 30% is roughly a one-in-three chance. Pretend you had three marbles in a bag, one red and two green. You blindly reach in and pull out a marble. What are the odds you’ll get the red one? It’s one in three, right? But now pretend you get three chances. If you first pull out a green one, you throw it back and get another try, and then a third try. Doesn’t logic tell you that with three chances, you’re likely to succeed? Similarly, with three chances for rain, even if it’s just a one-in-three probability each time, you’re likely to get wet when the three periods in question have elapsed. Just thought we’d get this out of the way.
Can You Smell Rain Coming?
My grandfather could even track squirrels with his sense of smell. What he was best known for, however, was his incredible nose for weather. He could tell a storm was approaching before anyone else in the county. One of my father’s earliest memories was running to warn neighbors that bad storms were coming so that they could get things covered. Most of us have smelt approaching storms. Source: Wikipedia Most of us have probably smelt that lovely fresh, earthy aroma of an approaching rain storm. He could smell it coming and even warn people about the strength and likelihood of tornadoes. (He went nuts once when he smelt a hurricane coming.) He was an educated man (and became superintendent of the Vanderbilt, Texas school system) but the most educated part of him was his nose. In an era when radio coverage was spotty, especially in the country, the neighborhood practically thought of him as a medicine man. Now scientists have discovered why people can smell the storms so far away. A sensitive snout is smelling ozone, petrichor and geosmin; in other words, the nose smells oxygen, the debris that raindrops kick up and wet bacteria.
First comes the ozone, the oxygen fried by lightening that changes its chemistry for O2 to O3. This has a sweet, pungent zing and winds carry it down from the upper atmosphere to your waiting nose. If you smell a lot of that—look out!
Ozone is produced by lightning, including this monster strike. Source Wikipedia Then comes the raindrops. Scientists discovered that water drops hitting surfaces like soil or leaves knock particles up in the air. A raindrop hitting an uneven surface traps bubbles of air that shoot upwards and burst from the top of the water droplet like fizz in a champagne glass. These bubbles can float long distances before they pop and you can smell the pollens, dirt, oils or city scum. Nature’s champagne is called petrichor. Finally, the wet soil triggers the bacteria or blue-green algae to release geosmin, that great earthy smell so loved by gardeners. Drops of water spray aerosols into the air that you can smell downwind. Source: Wikipedia That explains why my grandfather’s educated nose could smell approaching storms. How he tracked those squirrels through the woods remains a mystery.
Cancer Zodiac Sign: Personality and Compatibility
Learn about what Cancer Zodiac Sign means and how it affects your life. Get information about Cancer dates, symbol, personality, and compatibility.
Cancer is the fourth astrological sign in the Zodiac, originating from the constellation of Cancer. Under the tropical zodiac, the Sun transits this sign between about June 21 to July 21. If your birthday falls in this date range, you have a Cancer Sun Sign.
The symbol of the Cancer Zodiac Sign is usually the crab and its claws. Sometimes, you may see the crab sign symbol depicted as a sideways “69” to represent crab claws or a woman’s breast.
You are the Patriarchs and Matriarchs of the Zodiac. Family means everything to you. You watch over your brood with determination and zeal. You can be counted upon to be at every graduation, wedding, surprise party, or barbecue that has anything to do with your relatives. They are definitely your tribe, and you are very generous with all of them. Many of you have very strong careers, as you know that this is the best way to provide for your family. Others love being stay-at home parents because who could care more about your children than you? You want to see them succeed and will do everything in your power to make that happen. Home and family are so important to you that you are willing to submerge your own wants and desires for the good of your immediate group. Often quite ambitious, you seek to get ahead in order to provide the best for your loved ones. Cooking comes naturally to you as you understand that nourishment is the key to good health. Chefs are among your ranks, as are nurses and doctors who take care of the physically disabled or ill. You are sensitive to the extreme and can always tell when something is wrong with one of your charges. Walking into a room full of depressed people instantly depresses you. You like soft tones and low lights and prefer to allude to the things that you find difficult. Like your totem, the crab who sidesteps, you may have trouble being direct. This can lead to misunderstandings, so you need to find a way to be clear. Writing things may be a solution. Interestingly, on July 4, 1776, there was not just one planet in Cancer, but four. Since we celebrate our birthday as a nation on this date, is it any wonder that we have trouble dealing with our issues? As a partner or a parent, you are among the best. All those around you never have to wonder if you care because you show it repeatedly.
Best matches for you:
Taurus knows how to make you their one and only, and the back rubs are to die for. Pisces understands your sensitive nature and is always willing to listen to the tales of your day. Good matches for you: Scorpio can read your moods and will delve into the levels of emotions with you. Virgo will keep things organized and make sure that the rent gets paid.