TOPEKA (KSNT) – As we head further into spring our jetstream is becoming a bit more active and so is our weather. A shortwave disturbance, or small storm system, is making its way into much of the central plains. With its arrival, we are seeing moisture and cloud cover within our neck of the woods.
Prepare for Science below!
A unique atmospheric phenomenon is also showing up: Virga. Pictured below is one of the many ways virga can appear. It is a result of precipitation, rain or snow, falling from the clouds and melting before it reaches the ground. This occurs because the precipitation encounters a dry layer of air in the lower levels of the atmosphere (right above us at the surface).
Virga can sometimes be referred to as ‘fallstreaks’ due to the way it looks falling through the sky. Almost like a paint brush. Virga is also a bit more common in drier climates such as Denver or immediately East of the Rocky Mountains. Northeast Kansas is known for having a bit more moisture due to our proximity to the Gulf of Mexico, but in this case, we have enough dry air at the surface to create the phenomenon.
Pictured below is a water vapor satellite view of our region, the Central Plains. Blues and whites are depicting cloud cover and precipitation while yellow shows dry air. This tool is great for helping identify areas of moisture – or lack thereof. Notice the dry air is below the moisture in Kansas.
To take it a step further, we can also look out our weather balloon sounding from this morning (pictured below). Without diving into specifics too much, the red line shows air temperature and the green line shows dewpoint temperatures. This data shows what our atmosphere looked like as the weather balloon ascended through the atmosphere just before sunrise this morning.
The main thing to point out here is the big gap between the red and green lines near the bottom. That indicates fairly dry air at the surface. Meteorologists call that ‘dewpoint depression’ or the difference between air temperature and dewpoints.
This graph as a whole is called a ‘Skew-T’ if you’d like to learn more about it. This was produced from the National Weather Service’s weather balloon this morning in Topeka.