What Causes Wind?

Hope you enjoyed the brief return to winter with last nights snowfall.  We had an inch on the ground at 10pm which is already melting.  It snowed quite hard and had a large liquid content so any measurements of actual snow will be hard to make especially with the rain which fell before changing to snow.  The feature image is a snapshot from our webcam at daybreak.


Today we will be looking at the wind for those of you who wonder where it comes from.  To understand it we have to look at the big picture of the sun and the tilt and rotation of the earth.  We already know gravity holds our atmosphere in place – when we figure in all the other stuff which creates our weather patterns we can see why our planet is unique and allows life to exist.

Our oceans and atmosphere are similar in that both have large currents which are changeable due to the suns energy.

The energy which drives the wind originates from the sun which causes the earth to heat unevenly causing warm and cool spots.

Sea breezes occur when inland areas heat up on sunny afternoons. That warms the air, causing it to rise. Cooler air rushes in from the ocean to take its place and a wind is born. By late afternoon, a strong breeze can be blowing dozens of miles inland. A similar effect can occur near big lakes, where the wind is referred to as a lake breeze which we are familiar with here in southwest Michigan.

Land breezes come at night, when inland temperatures drop enough that the ocean is now warmer than the land, reversing the effect.

 

Global Patterns

Because the Coriolis effect causes global winds to curve, they cannot flow directly from the poles to the equator. Instead, global winds travel along three routes in each hemisphere. These routes, which circle the world, are called global wind belts.

Similar forces produce global wind patterns that affect climate. The tropics, for example, are always hot. Air rises here and spreads north and south, high above the land. Lower down, air is pulled in from the north and south. The Coriolis effect, an offshoot of the Earth’s rotation, makes moving air masses curve, so that the winds converging on the Equator come from the northeast in the Northern Hemisphere and the southeast in the Southern Hemisphere. These winds are called the trade winds.

Farther from the Equator, the surface winds try to blow toward the Poles, but the Coriolis effect bends them the opposite direction, creating westerlies. This is why so many weather events in the United States come from the west.

At latitudes higher than about 60°, cold surface winds try to blow toward the Equator, but, like the trade winds, they are bent by the Coriolis effect, producing polar easterlies.

Highs and Lows

Within the mid-latitudes, weather effects create high- and low-pressure zones, called highs and lows, respectively. Air moves from areas of high pressure to low pressure. As it moves, however, it spirals due to the Coriolis effect, producing the shifting winds we experience from day to day, as highs and lows drift under the influence of the prevailing westerlies.

Winds reaching the center of a low-pressure area have nowhere to go but up. This causes moisture to condense into clouds, producing storms. At the center of high-pressure areas, dry air descends from above, producing fair weather.

On a smaller scale, colliding wind patterns can produce convergence, in which air also has nowhere to go but up. If one of the winds is a humid flow from a warm ocean such as the Gulf of Mexico, the result can be powerful thunderstorms and tornadoes.



 

Seven Day Forecast

GRAND RAPIDS WEATHER


KALAMAZOO WEATHER


LANSING WEATHER



Enjoy today because we will begin a wet unsettled weather pattern tomorrow through Thursday with chances of storms Tuesday night.


 

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Sandy (Hudsonville)
Sandy (Hudsonville)

MV I like the photo and can relate to the same at my house. Today was beautiful- even got out for a walk with the dog. He loved it too. All the great smells of Spring. He was a little surprised by the snow last night. Looks like a rainy week ahead. Great for the flowers.

Mark (East Lansing)
Mark (East Lansing)

Nice day out. We got a lot accomplished. Pressure washed the deck. Got out the deck furniture. Cleaned up the flower beds. Fertilized the lawn. I’m ready for dinner and bed.

Rocky (Rockford)
Rocky (Rockford)

The new cpc gives us cool, wet weather through at least mid May! Incredible!

Rocky (Rockford)
Rocky (Rockford)

If you like wet, cool and breezy weather you will love this weeks weather! Get prepared for horrendous weather!

Mookie
Mookie

What? No accumulating snow for GR? All week Rocky has been posting about several inches and snow shoeing. Whoops again!

INDY
INDY

What? just below average temperatures for this time of year nothing new from this cool Spring… Welcome back..INDY!

Mookie
Mookie

April is above average

Rocky (Rockford)
Rocky (Rockford)

2019 is well below temps.

Rocky (Rockford)
Rocky (Rockford)

What ? Mookie making a ridiculous comment again!

Slim

No snow fall here at my house and just 0.04″ of rain. At the airport the official readings for GR was 0.12″ of pricip and just a trace of snow fall. The official low was 33 and the low here at my house was 32.
Slim

Rocky (Rockford)
Rocky (Rockford)

What was the highest snowfall total in Kent county? Should not have been in a WWA!

Alice (Cedar Springs)
Alice (Cedar Springs)

No snow here. The sun is shining and it’s going to be a beautiful day!

Thanks for the informative post about wind!

Andy W
Andy W

Rocky, you gotta drive down to Michaels to get some snowshoeing in!

Rocky (Rockford)
Rocky (Rockford)

Not quote enough snow, so I will need to settle for golfing today!

Mark (East Lansing)
Mark (East Lansing)

No snow here, but we received 0.1″ of rain.