(Conversation) – It may seem like a storm comes out of nowhere and hits with a sudden explosion. They may be hundreds of miles long and spread across several states.
But they all have one thing in common. It is a change in air pressure.
Air in the atmosphere is forced from high pressure to low pressure areas, just like it pops out of a car tire when the valve is open.
The stronger the pressure difference, the stronger the wind will ultimately occur.
In this forecast from the National Oceanic and Atmospheric Administration on March 18, 2025, “L” represents a low-pressure system. Shady areas in New Mexico and West Texas represent strong winds and low humidity combined to increase the risk of wildfires. NOAA Weather Forecast Center
Other forces related to Earth’s rotation, friction and gravity can also change the speed and direction of the wind. But it all starts with a change in pressure over this distance. Meteorologists like me call it a pressure gradient.
So how do you get the pressure gradient?
A strong pressure gradient is ultimately present in the simple fact that the earth is spinning round.
Because the Earth is round, the sun is fictionalized directly during the day at the equator rather than the pole. This means that more energy reaches the surface of the Earth near the equator. And it causes both warmer the lower part of the atmosphere where the weather is produced, and higher pressures on average than the pole.
Nature doesn’t like imbalances. This temperature difference results in strong winds occurring at highlands at mid-latitude positions, just like the continental continent, as in the US, and it is a jet stream, which has a major effect on the winds that feel on the surface, despite being several miles above the atmosphere.
A sandstorm produced by the spill winds from a large monsoon storm, an aerial panorama of “haboob” approaching the outskirts of Phoenix, Arizona.
As the Earth rotates, these highland winds blow from west to east. Jetstream Waves – Air can diverge or spread at certain points as a result of Earth’s rotation and surface land, topography and ocean fluctuations. As air spreads, the number of air molecules in the column decreases, ultimately reducing the air pressure on the Earth’s surface.
Pressure can drop considerably in days or just hours, leading to the birth of a low-pressure system. It’s what we call a meteorologist.
An opposing event chain where air converges elsewhere can form high pressures on the surface.
Between these low and high pressure systems there is a strong change in pressure over a distance, or pressure gradient. And the pressure gradient leads to strong winds. The rotation of the earth causes these winds to spiral around high and low pressure areas. These highs and lows are like large circular mixers, where air is blown clockwise around high pressure and counterclockwise around low pressure. This flow pattern blows low air northwards, then the low air blows southwards towards the low equators, towards the east of the low poles, towards the southwards.
As the jetstream waves move from west to east, the surface is low, high, and with them the corridors of strong winds.
That’s what the US experienced when powerful cyclones caused thousands of miles of wind, launched sandstorms and spread wildfires, causing tornadoes and blizzards in the central and southern United States in March 2025.
Blow away the dust storm and spread the fire
The jetstream over the US was the strongest, and in many cases the most “wavy” in the spring.
Winds associated with large-scale pressure systems can be very strong in areas with limited friction on the ground, such as the flat, forested terrain of the Great Plains. One of the biggest risks is sandstorms in arid regions of West Texas or eastern New Mexico, exacerbated by droughts in these regions.
It struck Albuquerque, New Mexico on March 18, 2025. Another dust storm that several Kansas data caused deadly stakes involving dozens of vehicles on the I-70. AP Photo/Roberto E. Rosales
If the ground and vegetation are dry and the air is low in relative humidity, strong winds can also spread wildfires uncontrollably.
If pressure gradients interact with the topography, even more intense winds can occur. Winds can rush faster descents, like with Santa Ana’s winds that promoted catastrophic wildfires in January.
Violent tornadoes and storms
Of course, winds can become even stronger on local scales associated with thunderstorms and become more violent.
When thunderstorms form, hail and precipitation form, air can rapidly fall downdraft, causing very high pressure under these storms. That pressure forces air to spread horizontally when it reaches the ground. Meteorologists invoke these linear winds and the process of forming them is downburst. Large thunderstorms or chains moving across an area can cause large zones of winds above 60 mph, known as dereko.
Finally, some of the strongest winds in nature occur in tornadoes. They form when the wind surrounding a thunderstorm changes speed and direction at height. This could cause some of the storm to spin and cause a series of events that could lead to a tornado, and could have a 300 mph wind in the most violent tornado. How a tornado is formed? Source: NOAA.
Tornado winds are also associated with strong pressure gradients. The pressure within the tornado centre is often very low and varies considerably at very small distances.
It is no coincidence that locally violent winds and tornadoes often occur in localized violence from thunderstorms. Often, low-tensity cyclones draw warm, humid air north and north with strong winds from the south, an important component of thunderstorms. The storms are also more severe, and if the jetstream is in close proximity to these low-pressure centers, it could generate tornadoes. Winter and early spring can cause cold air to blow south along the northwest side of the powerful low.
Therefore, the same waves in the jetstream lead to strong winds, pose a danger of dust and fire in one area, while simultaneously causing tornadoes and blizzards in other areas.
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