Weather2020 Forecast School

Learning Weather ForecastingFrom 1 Day to 200 Days Into The Future

By Gary Lezak

Introduction

Meteorologist Gary Lezak will introduce us to meteorology. Gary received his Bachelor of Science Meteorology degree in 1985 from the University of Oklahoma. He has been rated one of the most accurate weather forecasters in the nation and he is going to be providing some insight into weather forecasting both short and long range using the Lezak Recurring Cycle (LRC). This is breakthrough technology that is now being used around the world in the 1Weather app and on Weather2020.com.

This introduction into weather forecasting will begin with an understanding of the troposphere. We will then take you through one of the most important and visual parts of weather forecasting, the clouds, storm systems, and surface analysis. By the end of this educational series you should have enough knowledge to strengthen your weather forecasting skills.

Chapter 1: The AtmosphereMost of the weight of the atmosphere is within the troposphere, which is 78% Nitrogen, and 21% Oxygen. The troposphere begins at the surface of the earth and extends up to around 5 to 13 miles depending on the location and season. During the winter the troposphere is lower and it is more expansive during the warm months. For the same reason it is much higher at the equator than it is at the poles.

The temperature in the troposphere decreases with height due to lower density of the gasses with height. The air becomes thinner and the temperature drops. The top of the troposphere is called the tropopause. Did you know that you have visually experienced the top of troposphere many times in your life?

The cumulonimbus cloud, you can see here, showcases the entire troposphere. In the troposphere the temperatures cool with height. When a cumulus cloud is growing, water vapor is condensing into cloud droplets and heat is released in this condensation process. The heat allows the air within the rising cloud to be warmer than the surrounding environment and the air will continue to rise and the cloud grows. There is an upper limit, however, to how high the cloud can grow. Once the cloud hits the stratosphere, where the air begins warming again, the cloud is forced to stop growing and this can be seen in every thunderstorm that forms. The anvil spreads out, the top of the thunderstorm, and this shows that where the top of the troposphere is located. So, when it is raining, we are literally seeing the effects of the cumulonimbus cloud from the ground all the way up to the bottom of the stratosphere.

All of the weather we experience here on earth forms within the troposphere. The other layers of the atmosphere likely have very little influence on the turbulent layer that lies near the surface. What’s incredible is how thin this layer really is. Remember the troposphere goes up to around 12 to 14 miles at the most. The largest cumulonimbus clouds have been known to reach close to 70,000 feet up. So, let’s say the upper limits of the troposphere is 14 miles. And now, let’s imagine you driving from Shawnee, KS across the Kansas/Missouri border to Raytown, MO, both suburbs of Kansas City. If you were to draw a straight line that distance would be 14 miles. Now, look at the second map below. Look how tiny of a distance that is when you think of the bigger global picture.

99% of the atmosphere’s water vapor is contained in this area near the earth’s surface, within the troposphere. And 75% of the weight of the atmosphere is in this layer.

The next time you look up at the sky, try to think of the troposphere, and what is happening in this layer. This is just one of the basic topics that we need to learn to become a great weather forecaster.

This diagram comes from http://scied.ucar.edu/shortcontent/troposphere-overview. This shows what is happening within the troposphere and what happens above the tropopause. The Ozone layer is up in the stratosphere, and the amount of solar radiation that reaches the surface of the earth is affected, but the weather we experience on earth is driven by what happens within the lowest layer, the troposphere. The process of developing clouds and precipitation can be quite violent and we will be discussing this turbulence in the cloud series.

Clouds are the basics of weather forecasting. Getting a good understanding of the cloud types, being able to identify them in the sky, and understand at least a little bit in how they form will help you become a better weather forecaster.

In this chapter we will go over the process of how clouds form and we will begin testing our skills by just looking up at the sky. The cloud chart here shows all of the basic cloud types and the levels that you are most likely to experience these.

Chapter 2: Clouds

As we discussed in chapter 1 99% of the water vapor in the atmosphere is contained within the troposphere. The process of cloud development begins with by looking at the water cycle here on Earth.

In this diagram you can see the full water cycle. It begins with evaporation. Water evaporates from the large water areas around our world. The water vapor that is added to the air just needs a lifting mechanism, something to create rising air, and then water vapor can condense into clouds. This is the next process, condensation. Then, incredibly, the clouds can build with precipitation forming and then being released back down to the ground and the water cycle is then completed by the runoff of the rain and melted snow back into the ground and bodies of water.

For a cloud to develop there is one essential ingredient that must be in the air. Extremely small particles called condensation nuclei must be in the air for water vapor to condense. If the air is perfectly clean then there would be no clouds. Condensation nuclei come in the form of salt particles from the oceans, dust particles, and other very small airborne particles that are too small to see. The main ways in which these get in the air are from ocean sprays, fires, dust storms, and other ways that we pollute the air as humans. In this diagram below you can see the complex process of forming a raindrop beginning with the nucleus of a very small airborne particle. These particles are called hygroscopic (“water seeking”) with an extremely light massof less than one-trillionth of a gram. Sea salt and table salt are hygroscopic. When it is extremely humid, salt from a salt shaker can become difficult to pour due to water vapor condensing onto the salt. Sometimes you can see these small particles before condensation occurs when there is an abundance of them in the air. This is visible when it seems hazy outside. So, what is a cloud. Yes, it begins with the condensation nuclei, but clouds are really visible when condensation occurs and billions of these small particles come together to form into clouds. Clouds are the basics of weather forecasting and we will begin a look into the cloud types in the next section.

There are ten basic cloud types and we will begin this discussion next week.

Cloud Types