Category Archives: Meteorology

The winter solstice (In Latin, sol, “Sun,” and stice, “come to a stop”) is the day of the year with the fewest hours of daylight. In 2015, this occurs for the Northern Hemisphere on Dec. 21 at 10:48 p.m. CST.

As Earth orbits the sun, its axis of rotation is tilted at an angle of 23.5 degrees from its orbital plane. Because Earth’s axis of spin always points in the same direction — toward the North Star — the orientation of Earth’s axis to the Sun is always changing as Earth orbits around the Sun. Continue reading →

As we head into December many people begin to watch the local lakes for the first signs of ice cover.

One of the most studied lakes in the world is our very own Lake Mendota. Among the various long-term observations of it that have been accumulated in the last 150-plus years are the ice-on and ice-off dates for each winter season. Continue reading →

No, it is never too cold to snow.

It snows in Antarctica — where temperatures are minus 70 degrees — though only a few tenths of an inch.

To get snow, the always-present water vapor in the atmosphere has to be converted to ice crystals. How much water vapor is in the atmosphere depends on the air temperature. Continue reading →

Accurate and precise measurement of snow accumulation is a difficult task.

The measurement tools are simple: a ruler or yardstick that measures in inches and tenths of an inch. Continue reading →

Our storm on Wednesday night and Thursday of last week was the first strong storm of the autumn/winter season. As you found yourself caught in the strong winds, you may well have wondered how do storms like this one come to be.

That has been the central motivating question in meteorological science for most of the past 100 years. Continue reading →