The reading arm usually is longer and may look like an arrow. You may need to make a special adjustment if you live at an elevation greater than 1,000 feet. Current Weather Observations. Digital barometers output pressure readings in digital format. Check to see whether your personal barometer has two needles. When the air is dry, cool, and pleasant, the barometer reading rises. Check it every year or so. Watch for the needle that follows pressure changes to move up or down from that fixed point. Since 1985, she has written numerous technical, user and training manuals for major corporations, public agencies and universities. The barometric pressure is a common reading that is included in weather updates, especially during hurricane season. The pressure readings for an area are mostly in the range of 29.70 and 30.20 inHg, with 29.92 inHg being the average pressure at the sea level. Notice that your barometer has two arms. Rapidly falling pressure indicates a storm is coming. What Causes Changes in Atmospheric Pressure, Predicting the Weather With the Barometer, 7 Types of Weather in a High Pressure System, Air Pressure and How It Affects the Weather, How a Barometer Works and Helps Forecast Weather, How to Make a Storm Glass to Predict the Weather, How to Read the Symbols and Colors on Weather Maps. If the reading falls between 29.80 and 30.20 inHg (100914.4–102268.9 Pa or 1022.689–1009.144 mb): A barometric reading below 29.80 inHg is generally considered low, and low pressure is associated with warm air and rainstorms. In Meteorology, What Is a Low-Pressure Area? Higher air molecules have fewer molecules pressing down on them from above and experience lower pressure, while lower molecules have more force or pressure exerted on them by molecules piled on top of them and are more tightly packed together. Barometric pressure can change rapidly when a front arrives or when a hurricane approaches. To understand your barometer and how atmospheric pressure is changing, interpret readings as follows (pay attention to units). Remember, changes in pressure are more important than exact readings - a downward trend is a general predictor of stormy weather and an upward trend suggests fair weather. When you go up into the mountains or fly high in an airplane, the air is thinner and the pressure is lower. Note the scale on your barometer. Connect to the Internet and go to a weather website. Locate a digital barometer. To submit your questions or ideas, or to simply learn more, see our about us page: link below. Set the movable dial to coincide with the needle marking the current pressure. The reading arm usually is longer and may look like an arrow. The Jet Stream: What It Is and How It Affects Our Weather, An English-German Glossary of Weather Words, How to Use Weather Maps to Make a Forecast. Changes in air pressure are caused by differences in air temperature above the earth, and the temperature of an air mass is determined by its location. Air temperature differences create wind and cause pressure systems to develop. Mount your barometer where it is easy to see and adjust. They are used mostly in laboratories and weather offices. Most often, meteorologists use the more precise millibar (mb), equal to exactly 100,000 Pa, to describe pressure. Read the instructions accompanying your barometer. She holds a Bachelor of Science in geology. Atmospheric pressure is also known as barometric pressure because it is measured using a barometer. Nonmercury, aneroid barometers work through a small, sealed metal chamber with most of the air inside drawn out. When atmospheric pressure remains steady, there will likely be no immediate change in the weather. Note also in which area the number falls. Read your instructions to learn whether it is necessary to turn this screw to set your barometer to the current pressure reading. You may need to make a special adjustment if you live at an elevation greater than 1,000 feet. Slowly falling pressure means little change in the weather. Erin Moseley is an advocate for science education. Compare readings to weather reports and other reports of barometric pressure to confirm the accuracy of your unit. 48 Hour Barometer Readings for Philadelphia, PA. Daily Weather Archive for Philadelphia, PA. Today's Weather Summary. For example, air masses above oceans are typically cooler than air masses above continents. A rising barometer indicates increasing atmospheric pressure and a falling barometer indicates decreasing atmospheric pressure. A barometer is a device that reads atmospheric pressure. Connect to the Internet and go to a weather website. If you are using an analog barometer at home or a digital barometer on your cell phone in the U.S., the barometric reading will likely be reported in inches of mercury (inHg). Read the number that lines up with the reading pointer to find the current barometric pressure. Call the weather service, the airport or a news outlet to obtain a current barometric reading. Generally, low or decreasing barometic pressure means cloudy, unsettled or wet weather, and high pressure or increasing pressure means calm and clear weather. Copyright 2020 Leaf Group Ltd. / Leaf Group Media, All Rights Reserved. Current Weather Observations. Hour (24) Reading Date & Time: Barometric Pressure: 0: 11/22/2020 - … Websites worldwide provide weather reports and isobar maps to monitor shifts in barometric pressure. Be aware that first you'll need to adjust your barometer for your altitude. Campers can use weather radios to track changes in pressure. You can look up historical data, barometric pressure readings from your geographical area, and readings from most areas worldwide. Calibrate your barometer only during a period of fair weather, not during stormy weather. Here's how to read a barometer and what those readings mean in terms of air pressure changes and what weather is headed your way. Often, weather forecasters refer to high- or low-pressure areas moving toward particular regions in order to describe predicted conditions for those areas. No matter how you find barometric pressure, if it's changing quickly, a change in weather is on its way. Pressures seldom increase or decrease 1 inch above or below the 30-inch mark unless weather conditions are extreme. She specializes in climate and weather. Check to see whether there is an adjustment screw on the back of an aneroid barometer. 48 Hour Barometer Readings for Fredericksburg, VA. Daily Weather Archive for Fredericksburg, VA. Today's Weather Summary. Pay attention especially if precautionary measures are advised. Daily Weather Archive for Toms River, NJ. For example, a weather map may feature a line connecting all points where the pressure is 996 mb and a line below that where the pressure is 1,000 mb. Remember, changes in pressure are more important than exact readings - a downward trend is a general predictor of stormy weather and an upward trend suggests fair weather. Rapidly falling pressure means cloudy and warmer conditions. The air pressure at sea level at a temperature of 59°F (15°C) is equal to one atmosphere (Atm) and this is the baseline reading for determining relative pressure. Today's Barometer Readings Yesterday's Barometer Readings. Most personal barometers are "aneroid" while scientific ones are "mercury.". Most barometers made prior to 1986 used the millibar scale; one hectopascal is equal to one millibar. Identify your type of barometer. Today's Barometer Readings Yesterday's Barometer Readings.