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Wednesday's Weather Word: Pressure Gradient

What is a pressure gradient?
Posted at 6:44 AM, Apr 12, 2017
and last updated 2017-04-12 06:44:13-04

Pressure gradient...sounds like an interesting combination of words right? So what is a pressure gradient and how does it affect you?

First lets start by breaking down each word...Pressure: in this case we're referring to atmospheric pressure which is the amount of force the atmosphere is exerting on the Earth. In general in meteorology we focus on areas of high pressure and low pressure. In areas of high pressure the atmosphere is putting more force on the Earth than in areas of low pressure.

The Earth is always trying to be in a state of equilibrium and in an effort to achieve that force moves from areas of high pressure toward areas or low pressure to try to correct the excess. This is why winds try to blow from highs to lows, other things affect wind direction like friction and the Coriolis Effect but that's for another blog post. The stronger the pressure difference the more intense winds will be.

Now lets talk about gradient...you're probably picturing a gradient where one color gradually changes into another color...and that's a lot like what we're talking about here. In terms of the Pressure Gradient Force the gradient is the change in pressure from areas of higher pressure into areas of lower pressure. The more difference between the high and low pressure the stronger the pressure gradient will be resulting in stronger winds.

The PGF is one of the main components of creating winds. So the next time you hear a meteorologist talking about the Pressure Gradient Force strengthening it means your area is being affected by a difference in pressure and will result in windy conditions.