Category Archives: Meteorology
The Southern Ocean around Antarctica freezes to form sea ice every year. Scientists use observations from satellites to monitor the sea ice extent throughout the year.
Sea ice melt in Antarctica is a seasonal occurrence that usually begins in September (the end of Southern Hemisphere winter) and continues into February (end of Southern Hemisphere summer). As the pole warms during summer, the sea ice around the continent breaks up and melts. Continue reading
Here we are halfway through the month of January, and it has been remarkably mild for those of us in southern Wisconsin.
Through Saturday, January has been 10.3 degrees above normal in Madison and 10.6 degrees above normal in Milwaukee. In fact, since Christmas Day, the temperature in Madison has averaged just shy of 9 degrees (8.93 degrees) above normal in what is usually one of the colder stretches of the year. Continue reading
The term “atmospheric river” has been in the news recently due to the flooding along the West Coast.
An atmospheric river is a narrow band of concentrated moisture in the atmosphere. It is a narrow moisture plume that is a few thousand miles long and only about 250 to 375 miles wide. The term was coined in the early 1990s. Continue reading
The recent winter storm that affected large portions of the United States just days before the Christmas holiday was remarkable in a number of dimensions.
It was an example of a “bomb cyclone” which simply means that the rate at which its central pressure dropped — about 2.5% in a single day — was extremely unusual. Even though a 2.5% change in central pressure does not sound like very much, it was responsible for revving up the extreme winds that brought wind chills into the minus 30s and ground blizzard conditions to a large portion of the Great Lakes states on Dec. 23. Continue reading
In meteorology and climatology, a mesoscale network, or mesonet, is a network of automated environmental monitoring stations designed to observe meteorological phenomena on the mesoscale. In meteorology, “mesoscale” refers to weather events that range in size from about 1 mile to about 150 miles.
Mesoscale events last from several minutes to several hours. Thunderstorms, snow squalls and wind gusts are examples of mesoscale events. Due to the space and time scales associated with mesoscale phenomena, weather stations comprising a mesonet are spaced closer together and report more frequently than the larger synoptic scale observing networks run by the National Weather Service. Continue reading