At IQ Weather, we like to teach you new and different ways to look at weather!
In our 24-lesson video- based course, we talk about clouds and how they are formed. Today I want to talk about visual clues you can use to tell whether or not the atmosphere is becoming more favorable for storm development…using the look of the sky!
If storms are in the forecast for a particular day, often the air has to become unstable before strong storms can form. When we say the air is unstable, we simply mean that the air is rising, which helps promote the formation of precipitation and storms.
If the air is stable, it means that there is little or no vertical motion.
The clouds that form in stable air are usually stratiform in nature…in other words…flat and fairly uniform. It is quite common to see a lot of stratocumulus clouds during the morning hours before a storms form. Stratocumulus clouds look like this:
As long as the air remains stable, the clouds will look that way. Often it will be overcast if the humidity is quite high.
As the air becomes unstable, look for the following visual clues that the air is starting to rise:
More sun will start peeking through the lower cloud deck
You will see the clouds getting thicker vertically
You will see more dark grey cloud bases
Those clues tell you that things are changing, and you need to pay closer attention to the weather situation! In the transition from stable to unstable air, the cloud types will start to change to more cumuliform, or vertically developed clouds. Cumulus-congestus clouds are much taller and are the beginning of thunderstorm development. These clouds are pretty much all updrafts!
Once the cloud turns into a thunderstorm, or cumulonimbus cloud, rain starts to fall and the storm is a combination of updrafts in the rain-free area under the cloud, and downdrafts in the rainy parts of the storm. Here is a fully developed cumulonimbus cloud.
Learning to watch the skies during spring storm season can be fun and helpful! The more you notice the changes, the more you can “read” the sky and figure out what is happening!
Speaking of storm season, typically May is one of the most active months for severe weather in the United States, and particularly in “tornado alley”. But it has been rather chilly across a good section of the country so far in May. Here is a look at how much of the U.S. is experiencing below average temperatures today.
This cool pattern may persist for a while longer which means we could have a more active storm period at some point in June. But for now, the latest severe weather stats show that this cooler pattern is keeping the number of tornadoes down so far this year! That is not a bad thing!
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