How sailors use atmospheric pressure data
What is atmospheric pressure in simple words?
Basically, it's the weight of air – more precisely, its pressure on the Earth.
The higher you are, the less air there is above you. That's why the pressure is lower at higher levels.
The pressure on the Earth's surface changes because of mixed temperatures. The lighter the air, the lower the pressure is. Warm air is lighter. That's why the pressure of warm air is lower.
Atmospheric pressure and wind
Air masses always tend to move to lower pressure areas. We call it wind.
Pressure difference is the only thing making the air move faster. The faster the pressure changes place to place, the higher wind speed is. All the other forces – like friction – only lower it or change the direction.
Sudden pressure changes spell stronger winds.
Basically, it's the weight of air – more precisely, its pressure on the Earth.
The higher you are, the less air there is above you. That's why the pressure is lower at higher levels.
The pressure on the Earth's surface changes because of mixed temperatures. The lighter the air, the lower the pressure is. Warm air is lighter. That's why the pressure of warm air is lower.
Atmospheric pressure and wind
Air masses always tend to move to lower pressure areas. We call it wind.
Pressure difference is the only thing making the air move faster. The faster the pressure changes place to place, the higher wind speed is. All the other forces – like friction – only lower it or change the direction.
Sudden pressure changes spell stronger winds.
Some tips from Met Office:
• A pressure change of 8 hPa over 3 hours leads to an increase in wind speed up to 8 points on the Beaufort scale (wind speed up to 20.7 m/s, moderately high long waves).
• A pressure change of 5 hPa over 3 hours means an increase in wind speed up to 6 points (wind speed up to 13.8 m/s, large waves begin to form).
• A pressure change of 8 hPa over 3 hours leads to an increase in wind speed up to 8 points on the Beaufort scale (wind speed up to 20.7 m/s, moderately high long waves).
• A pressure change of 5 hPa over 3 hours means an increase in wind speed up to 6 points (wind speed up to 13.8 m/s, large waves begin to form).
Atmospheric pressure in Windhub
We will start showing 3 hours pressure changes at each point soon. You can check the pressure in Hectopascals (hPa), as well as in Millimeters of mercury ( mmHg) and Inches of mercury (inHg).
We will start showing 3 hours pressure changes at each point soon. You can check the pressure in Hectopascals (hPa), as well as in Millimeters of mercury ( mmHg) and Inches of mercury (inHg).
