Category Archives: Meteorology

A reader wrote us last week with two questions prompted by careful observation: 1. Why does the wind speed tend to decrease after sunset? 2. Why does this effect seem less pronounced in late autumn and winter? Continue reading →

Our autumnal weather in southern Wisconsin last week was tame in comparison to the devastating blizzard that hit the western portions of South Dakota earlier this month. On Oct. 4, Rapid City, S.D., approached its all-time single-day snowfall record when it received 19 inches, ranking it the third-snowiest day in the city’s history. Interestingly, the two record-setting days ahead of it occurred in late April (in 1970 and 2001). Continue reading →

Radar, an acronym for Radio Detection and Ranging, was invented during World War II to detect aircraft, but precipitation frequently got in the way. The military’s noise is meteorology’s signal. Continue reading →

The typical speed of a falling raindrop depends on the size of the drop. Gravity pulls everything downward. As an object falls, it experiences a frictional drag that counters the downward force of gravity. When the gravity and frictional drag are balanced, we have an equilibrium fall speed that is known as the terminal velocity of the object. The terminal velocity depends on the size, shape and mass of the raindrop and the density of the air. Thus, it is worth talking a bit about the shape and size of raindrops. Continue reading →

The National Weather Service, or NWS, is a part of National Oceanic and Atmospheric Administration (NOAA). The NWS provides “weather, hydrologic, and climate forecasts and warnings for the United States, its territories, adjacent waters and ocean areas, for the protection of life and property and the enhancement of the national economy.” Continue reading →