Undular Bores (Atmospheric Gravity Waves)

Atmospheric gravity waves, known as undular bores, are waves in Earth’s atmosphere that often show up quite well on satellite and radar imagery. They are notorious for creating wave-like clouds, which clearly propagate as waves when viewed in rapid time-lapse photography.  Low-level atmospheric stability is implicated in the formation of undular bores.  Large static stability […]

Visiting the Chapman, Kansas, EF-4 Tornado Damage

On May 25th, 2016, a large and violent, long-track tornado tore through the landscape across north-central Kansas causing extensive damage along Interstate 70 between Abilene and Chapman, Kansas. What was a marginal day for severe weather ended up producing one of the most violent tornadoes of the 2016 season. We visited Chapman on Saturday, July 23rd, […]

Heat Index Calculator & Charts

The heat index is an estimate of how hot the air “feels” to the human body and provides a relative indication of potential health risks. Among others, the two primary factors in the heat index equations are temperature and water vapor (i.e., moisture/humidity). Humidity affects the efficacy of perspiration to evaporatively cool the skin. When […]

How Many Days Until Fall 2017?

The fall (autumnal) equinox will occur on Thursday, September 22, 2017 at 20:02 UTC. In the U.S., at 4:02 pm EDT, 3:02 pm CDT, 2:02 pm MDT, and 1:02 pm PDT. In the Southern Hemisphere, it will be the start of spring.  The Duration of Fall 2017: 89 days, 19 hours, and 26 minutes Fall […]