|Long train on left, Blue Sky overhead, hazy horizon - Western Nebraska|
|Change in sky condition as we proceed East on I-80|
The clouds are formed as the humidity and temperature rise. With the Sun in eclipse starting just before 11am the full heat of the midday Sun will not be felt. The net effect will be a slowing of evaporation and net temperature increases.
|New Contrail being formed|
Another type of cloud often observed in the American Midwest is the contrail. Left behind by jets crossing the country at high altitudes these contrails can sometimes be a real bother in an otherwise clear sky.
|Persistent Contrails coming out of Lincoln Nebraska|
Despite rumors to the contrary, contrails largely consist of water with trace amounts of exhaust from the jet engines. The formation of contrails depends on the relative humidity. The higher the humidity, the better chance of seeing contrails.
For this reason, the western part of Nebraska and eastern Wyoming have better conditions. The lower humidity means that jets do not leave behind contrails.
For more about contrail formation see: http://science-edu.larc.nasa.gov/contrail-edu/science.php
...More random thoughts about TSE2017 to follow...