One thing that is often overlooked by preppers is the ability to read the skies. There may come a day where you no longer have access to that convenient weather app or Accuweather forecasts. Understanding the basics of meteorology can help you understand what the weather forecast may be for the near future. We first need to understand some of the common terms and phenomenon before we can use that knowledge to predict the weather. There are several aspects of weather that I will get into:
- Pressure and Fronts
- Weather Instruments
- Forecasting from Observations
Please note that I am not a meteorologist and not an expert in weather. As a little kid, I wanted to grow up and be a weatherman, but that changed shortly before I entered my undergraduate studies. Still, I have always been interested in the subject and feel that we all will benefit from knowing some basic meteorology – even if it is used to determine whether or not you should head back from your hike.
I am drawing very heavily on Weather: A Golden Guide. I have two versions of the book – a 1965 print that was discarded from the local library, and a 1987 version. Each of these copies have been in my possession for 30 years, and are well worn. The good news is that there is a newer version from 2001! It can be found on Amazon here, and it costs $6.95 new as of this article. I highly recommend picking up a copy. Are there more detailed books out there? Sure! But I have found none that are as good as this tiny little field book, and the price point makes it well worth it. Another excellent resource I have found and from where many of the pictures are coming from: http://www.namesofclouds.com/. This website is very comprehensive and covers many other oddball clouds I do not touch on.
Clouds: An Introduction
There are basically two types of clouds that exist: cumulus, and stratus. Cumulus are formed by rising air (they are “accumulated”) and look puffy. Stratus are formed below the saturation point and look like sheets. These types of clouds can be distributed into four families based on altitude:
- high, and
One other point of cloud names – the prefixes. “Nimbus” is added to clouds that typically produce rain or snow, “fracto” is added to clouds that are broke up due to wind, and “alto” means middle-layer or high clouds.
Low Clouds (base of ~6,500 feet and lower)
Stratus – low and uniform. Typically gray and produce drizzle or light snow due a lack of upward air movement.
Nimbostratus – The typical rain cloud, it has decent amounts of rain reaching the ground and is occasionally paired with some fractostratus if there are strong winds.
Stratocumulus – Irregular in shape, they look puffy or rolling. These do not typically produce rain but they can sometimes change into nimbostratus.
Middle Clouds (Base of ~10,000 feet)
Altostratus – look like sheets of gray or blue, or like veils. The sun/moon can be seen through the clouds, but it looks very veiled.
Altocumulus – patches of layers of puffy or rolling clouds and can be gray or white.
High Clouds (base of ~20,000 feet)
Cirrus – thin, and wispy, these clouds are composed entirely of ice crystals (hence the featherly look) and exist at 25,000 feet or higher.
Cirrocumulus – Rare clouds that form wavelike patterns and are often confused with altocumulus. They are thing and patchy and form between 20,000 feet and 25,000 feet. Typical of cold weather.
Cirrostratus – Thin sheets that form high, they often cause the sun and moon (as seen below with the moon) to create a halo effect due to its composition of ice crystals.
Towering (base as high as 14,000 feet)
Cumulus – These are the puffy, cotton candy looking clouds you all know. They form during the day by rising warm air. Generally fair weather clouds.
Cumulonimbus – These are the thunderheads that you also all know. Strong vertical air currents push the cloud high into the sky, with the signature anvil shape occurring at 75,000 feet because the clouds become heavier than the air. These clouds produce thunderstorms and tornadoes as well as large raindrops (because the strong vertical wind keeps pushing the drops up to collect water until they are heavy enough to fall).
These are not really used anymore, but I figured I would include them just as additional reference information.
Hopefully, you found this informative. Stay tuned for the next post on wind, which will be considerably shorter. Please feel free to add your thoughts and any additional information you may have in the comments below!
Picture Sources: www.wikipedia.com, www.namesofclouds.com, www.study.com, www.whatisthiscloud.com, http://cdn.zmescience.com, https://www.thoughtco.com/symbols-on-weather-maps-3444369