Category Archives: Meteorology
We cannot yet forecast tornado occurrence with any accuracy. One problem is the small size of a tornado, which is a narrow column of strong winds that rotate around a center of low pressure.
Over the last 60 years, forecasts of the development of large-scale low-pressure systems, which often organize the ingredients needed to form a tornado, have steadily improved. Because of these advances, meteorologists are better able to predict those conditions a few days in advance, enabling forecasters to identify counties where there is a threat of severe weather sometimes as many as three days in advance. Two days in advance of the recent EF-2 tornado that hit southeastern Polk County, the National Weather Service’s Storm Prediction Center’s convective outlook issued a slight-risk for the area. Continue reading
Drought in the United States has been assessed by a number of different measures over the last several decades. One of the older such measures is the Palmer Drought Index introduced in 1965. The Palmer Index is based on a … Continue reading
Recent spring mornings have produced wet lawns. To explain this, we start with the fact that air contains water in the gas phase, called water vapor. Dew is made of liquid water that has condensed from some of the water vapor in the air.
Dew occurs when objects cool. A common example of dew formation is when drops of liquid form on the glass of an ice-cold drink. Dew forms when the object, such as the glass, cools down to the dew point temperature. Continue reading
If you are involved with gardening, you probably are aware of the hardy zones listed on seed packets.
Southern Wisconsin is largely in zones 5a and 4b, while northern Wisconsin lies in zones 3a to 4a. Continue reading