What is the water cycle and can the cycle be disrupted?

A follower asked, “if the water cycle is real, how can there be water shortages?” In light of the recent drought in Texas, which ultimately ended with the historic rainfall during the month of May 2015, and the ongoing devastating drought in California, I thought I would make this brief post. What is the Water … Read more

What is the Weather-Ready Nation Initiative?

The United States is also home to the most frequent occurrence and the largest variety of extreme weather events of any other country in the world.  These events include, but are not limited to, extreme heat/cold, snowstorms, tropical storms and hurricanes, droughts, areal and flash floods, hail storms, and tornadoes.  While none of this is … Read more

What is Cold Air Damming (the Wedge)?

Cold-air damming (CAD), often called “the wedge” in the Southeast, is an interesting meteorological feature that can result in tricky forecasts for meteorologists. Topography plays a major role in CAD events, and you need a mountainous range for this feature to develop. While CAD can occur in the Rockies, it is predominant east of the … Read more

What is dynamic cooling of the atmosphere?

In atmospheric dynamics, a negatively tilted upper-level trough tends to be stronger and much more dynamic, particularly if there is a closed upper low Both rising air and heavy precipitation (especially snow) work to cool the atmosphere from the top down.  This is called dynamic cooling and it is extremely efficient at turning an otherwise … Read more

Weather Myths: Too Warm for the Snow to Stick?

Before I begin this piece, I want to present a challenge.  The following chart shows the actual high and low temperatures for a full month in Atlanta, Georgia. *A condensed version of this writeup was also featured in the Douglas County Sentinel. Challenge: Can you spot the day with a historic snowstorm? During this particular … Read more

A Brief History of Weather Forecasting

The Weather Bureau, now known as the National Weather Service, was established on February 9, 1870 by the 41st United States Congress and signed by President Ulysses S. Grant. On March 29, 1870, the new weather forecasting service was officially assigned to the U.S. Army Signal Service within the Department of War and given the … Read more

Cause of Fireworks Smoke & Fog at the ACC Championship on 12/6/14

If you watched the GA Tech/FSU ACC Championship Game in Charlotte, North Carolina tonight (12/6/14), you may have seen the smoke-filled stadium following the pre-game fireworks show.  A heavy fog was already in place, which virtually guaranteed poor visibility of the fireworks; but to make matters worse, the smoke from the fireworks had no where … Read more

Difference Between Single vs. Multiple Lake Effect Snow Bands

Radar image showing both single and multiple snow bands.

In an earlier article, we discussed the dynamics and thermodynamics of lake effect snow. In this post, we discuss the meteorological differences between single-band and multiple-band lake-effect snow events.  Keep in mind that all lake-effect snow events are fueled by moisture and latent heat flux from the relatively warm lake water; these fluxes are already … Read more

Lake-Effect Snow: The Physics of Colossal Snow

Lake effect snow formation illustration

One of the most awe-inspiring forces of nature is lake-effect snow. The amount of latent energy required to produce the lake-effect convection is astounding, and in some situations, snowfall rates can reach as high as 5 to 6 inches per hour.  In this article, we discuss the atmospheric physics, dynamics, and thermodynamics responsible for the … Read more