why does it rain more in the mountains then in the valleys?

Answer 1

as the thunder clouds rise to move over and past a mountain range, the density of the air changes. the moisture is too heavy for the less dense air and can not stay in the clouds anymore so rain drops precipitate.

by contrast, clouds in very dense air in the bottom of a valley can hold lots more moisture and thus prevent it from raining until the moisture content rises.
Humidity is a measure of the amount of moisture in the air and when its raining, it has to be 100% humidity because the air can no longer hold any more moisture, which is why its raining in the first place! they call this supersaturation.

Answer 2

Well my answer is that the valleys in Northern tear of PA the mountains get more rain then the valleys, so there for the valleys get less then higher up, because pressure is higher in the valleys here so that's why we get more on the Mountains then in the valleys, Northern Mansfield PA were my school is they get missed by a lot of heavy precip most of the time, its because its like there is a week little high in the valley's that blocks the worst of the storms from the valleys so that all i am Johnny Maddox with Weather Whys have a wonderful day.

Answer 3

The ascent of air is known as convection.This convection can either be forced convection or free convection.In the case of an unstable atmosphere,the motion upwards is free (free convection)and due entirely to its buoyancy.The ascent of air when it is crossing a mountain barrier or when a warm airmass is being undercut by cold air and forced aloft, then the convection is a forced one.
So when a mountain range act as a barrier to air flow,forced convection occurs and the the airflow lifts the air mass on the windward side of the mountain.The reduction of the pressure within the rising airmass produces adiabatic cooling and if the air is sufficiently moist,condensation occurs and cloud forms resulting in rain on the windward side.
A typical example is the heavy rainfall on the western side of Western Ghats in the peninsular India when the south-west monsoon starts in the beginning of June,every year.
We can see another example in Europe.When the Alps mountain block the the southerly wind,air is forced to rise resulting in the precipitation in the form of rain and snow.This precipitation produces another effect called Fohn effect.
During the above precipitation,the moisture content is reduced and the air becomes very dry and this dry air descends on the other side(leeward side) of the mountain.While descending it becomes warmer due to adiabatic compression.Some clouds are formed in the leeward side and the base of cloud can be seen at a different level than that of the windward side .
Further ,on arrival at the bottom of the leeward side, the air will have a higher temperature than it was before when it commenced its journey at the bottom of the windward side. This effect is called fohn effect and the wind is called Fohn wind.

Answer 4

The mountains obstruct the passing clouds .

The obstructed clouds try to rise higher to cross the mountain .

As they rise higher they encounter much colder climate and the moisture brought by them begins to condense in the form of water droplets.
These droplets come down in the form of rain !!!

In the plains ( rather than valleys . it is incorrect here to say valley here as the mountains and valleys coexist and rains come down in the valleys ultimately at least in the form of rivers and rivulets !!!!) there is no such obstructions and the rain clouds pass unhindered without showering the land below .

Answer 5

more rain in mountains because of orographic rainfall which the high altitude of the mountain moves the clouds up further in the atmosphere which the clouds reach dew point and rain.

Answer 6

It is because the mountains are "closer to the clouds". It is because they are so high up that the atmosphere is very different. This is also the reason why it is usually very cold up in the mountains also.

Answer 7

It's called orographic lift. The air flowing over the mountains is lifted, hence cooled, and if cooled below the dew point, you get rain.

Answer 8

because the mountains are closer to clouds and the clouds hold the rain;)

Answer 9

wind sheer across and up one side ,create,turbulance and down draft on the other,, ie rain or snow