Barometers: How they predict the weather

October 18, 2024

A Barometer is a weather monitoring instrument used to measure atmospheric pressure. They were designed with the knowledge that changes in atmospheric pressure results in changing weather patterns. Although anyone can use a barometer, they are widely used by meteorologists to predict short-term weather changes in a specific area.

High-pressure and low-pressure:

High atmospheric pressure usually means that we will recieve 'good weather' and calm conditions including, clear skies, light winds often just a gentle breeze, with no chance of rainfall.

Low atmospheric pressure indicates that skies will become cloudy, with a high chance of rainfall and windy conditions.

Atmospheric pressure is measured in the unit ‘hPa’ (hectopascal), it’s important when checking your barometer for pressure measurements you are aware of both high and low-pressure unit ranges. The needle covers a range between 960 and 1060 hPa, if the needle approaches and exceeds 1015hPa this indicates that atmospheric pressure is high and good weather is guaranteed. However, if the needle begins to drop rapidly below 1000hPa or exceeds 980hPa, this means a thunderstorm is set to strike. A calmer fall in atmospheric pressure simply indicates that cloudier and potentially rainy conditions are set to arrive.

Barometers:

Barometer types to choose from are either Mercury barometers or Aneroid barometers, at ClimeMET we provide a stylish range of traditional and contemporary aneroid barometers, measuring atmospheric pressure in either mmHg or mb. Suitable for use in both your home and garden, perfect for avid weather watchers and those worried about getting caught out in the rain!

The 'Constable' Banjo Barometer CM4280

An aneroid barometer has a sealed metal chamber with a flexible capsule inside that expands and contracts depending on the atmospheric pressure, the measurements are then displayed by a needle that is attached to the hidden capsule and adjusts accordingly to the pressure-volume.

Mercury barometers are the oldest style of barometer, They involve a glass tube with a small amount of mercury liquid inside that rises and falls within the tube depending on the atmospheric pressure.

FAQs:

What are the different types of barometers?
The main types of barometers are:

Mercury Barometer: Uses a column of mercury to measure pressure.
Aneroid Barometer: Uses a flexible metal capsule to measure pressure.

How do I read an aneroid barometer?
Read the position of the needle on the dial. The dial shows atmospheric pressure directly, usually in millibars (mb) or inches of mercury (inHg)

Can a barometer be used indoors?
Yes it can, however, ensure you place it away from any draft, direct sunlight, or manmade heat sources for the most accurate readings.

Can a barometer predict long-term weather?
Barometers are mainly used for predicting short-term weather, over the next 48 hours, they indicate immediate changes in weather rather than long-term predictions.

How do I set up my barometer?
Firstly, google the current atmospheric pressure using reliable sources such as the MET Office.
On the back of the barometer adjust the screw either + or – (whichever is necessary) so the needle at the front displays the correct reading.