Weather forecast and wind direction
- What is wind direction? How is it measured?
- Weather forecast and wind direction: What causes wind direction?
- Air pressure (Atmospheric pressure)
- Coriolis Effect
- Why is it important to know wind direction (and wind speed as well)?
- Instruments used to determine the direction of the wind
Together with temperature, humidity, clouds, …, the wind is one of the important elements of weather.
Wind, including wind speed and wind direction, is a significant element of weather and climate. It is considered one of the major driving forces of weather.
Meteorologists always take wind deep into account when making weather forecasts. With just a quick look at a daily weather forecast or seven days or 10 days weather forecast, you can quickly realize that wind is always included.
Are you curious about how important wind direction is to the weather, its effects on the weather, as well as the instruments that meteorologists use to measure the wind? Check out this article now to know more about the weather forecast and wind direction and wind speed as well. Here we go!
What is wind direction? How is it measured?
Wind direction is the direction from which the wind originates. For example, a northerly or north wind originates from the North, and it blows from North to South. Wind direction is measured by an instrument named wind vane or weather vane.
Wind direction is the direction from which the wind originates
Typically, wind direction is reported in degrees. A wind direction of 0 degrees is due North on the compass, a direction of 180 degrees is due South, and 270 degrees would indicate a wind emanating from the west.
When it comes to the weather forecast and wind direction, people also talk to wind speed that determines how fast the wind is moving past a certain point. Meteorologists use anemometers to measure wind speed. It typically reported in knots, miles per hour, or meters per hour. One mile per hour (mph) is equal to 0.87 knots, and 0.45 meters per second.
Weather forecasts typically include the speed of the wind along with its direction. For instance, "a Westerly wind at 12 mph" is a wind blowing from the west at a speed of 12 miles per second.
Weather forecast and wind direction: What causes wind direction?
There are three primary factors coming together to create and determine wind direction. They are air pressure, the Coriolis Effect, and friction. Let’s see how each of these factors influences the wind direction right now!
Air pressure (Atmospheric pressure)
Air pressure is one of the main factors determining wind direction. Traveling from the areas of high pressure to the areas of low pressure, the air always attempts to balance out pressure differences.
Weather forecast and wind direction: Air pressure is one of the main factors determining wind direction
A high-pressure system and a low-pressure system are next to each other causing wind direction to flow clockwise and flow outward toward a low-pressure system. And the low-pressure system is what causes wind direction to flow counterclockwise and inward. This phenomenon is also referred to as a cyclonic flow that is one of the elements that can come together with other ones to create a tropical cyclone, hurricane, or typhoon.
Besides, heat and air pressure also cause the wind to shift direction. For instance, sea breeze forms when the land heats faster than the water, then the heated air rises above and blows from the higher-pressure water inland. On the other hand, a land breeze forms when the opposite happens.
As discussing the weather forecast and wind direction, it’s necessary to mention the Coriolis Effect as it’s one of the important factors influencing the direction of the wind.
Even though wind travels from high-pressure areas to low-pressure areas, it does not blow in a straight line, or it doesn’t flow directly from high to low. That is because the Earth is rotating from west to east. Well, this phenomenon is known as the Coriolis effect that can be seen closer to the pole regions.
Generally speaking, the spin of the Earth from west to east causes winds to travel and blow in a counterclockwise and clockwise manner. In the Northern Hemisphere, the Earth’s rotation causes winds to the right (and to curve to the left in the Southern Hemisphere).
Due to the Coriolis effect, in the Northern Hemisphere, winds blow counterclockwise around an area of low pressure and clockwise around an area of high pressure.
The additional factor affecting wind direction is friction. Surface-level winds are greatly influenced by friction, as this is where the wind encounters different surfaces.
For example, if the wind blows toward a building, then it has to go through a change in direction for sure. It could either go around the building or rise above it, but the presence of the building causes a wind direction change.
Besides, when encountering a rougher surface, the wind will slow down, resulting in a decrease of the Coriolis deflection. But encountering a smoother surface will cause the opposite.
Why is it important to know wind direction (and wind speed as well)?
As mentioned above, the wind is one of the primary elements of weather and climate. It is also related to the formation of different weather systems on the planet.
Wind transports temperature and moisture from one area to another, hence, weather conditions change with the change of wind direction. Or in other words, a change in wind direction and wind speed as well will result in a change of weather.
Weather conditions change with the change of wind direction
For example, feeling a gust of wind could be a sign of a thunderstorm approaching or another atmospheric turbulence.
Obviously, wind direction and wind speed are crucial for monitoring and forecasting weather patterns and global climate as well. That’s why it’s important to talk about the weather forecast and wind direction.
Instruments used to determine the direction of the wind
These days, people use different devices to measure the wind direction and the wind speed as well. Here are a few basic instruments:
Windsock. This device comes with a simple design. It is used to measure wind direction and also provides a rough idea of its intensity. Windsocks include a tubular piece of fabric or a thin and flexible fabric attached to the pole. Either the pole or the harness that’s attached to the windsock can rotate when wind direction changes, hence, the direction of the windsock indicates the wind direction.
Weather forecast and wind direction: Windsock is used to measure wind direction and also provides a rough idea of its intensity
Weathervane (also referred to as wind vane). This instrument works quite similarly to a windsock. It works by spinning and pointing toward the source of the wind the symbols of N (North), S (South), W (West), and E (East). Weather vanes are mounted on the highest spot of a structure like a building, for example, without obstructions that could block wind flow. The first recorded weather vane was invented as early as the first century BC by Greek astronomer Andronicus.
Digital wind vane. This instrument shares basic design elements with a classic weather vane, but it’s a lot more sophisticated. A digital wind vane is considered an essential component of a weather station.
Together with these instruments, meteorologists also use other tools to measure the wind, in which anemometers are important devices used to measure wind speed.
As you can see, wind direction is quite a complicated term to fully understand. Together with wind speed, wind direction can greatly affect the weather. That is the reason why it is essential to measure and forecast the direction of the wind (and the wind speed as well). Well, through this article “Weather forecast and wind direction”, we also knew what factors cause wind direction and how they influence wind direction, right? Plus, instruments used to measure and determine wind direction are also listed above. We hope that all the information included in this writing is interesting to you.