John was born in Baton Rouge, LA, and grew up near Birmingham, Alabama. As a teenager, his family moved to Madison, Wisconsin, and later to a small town in northeast Iowa. John traces his early interest in weather to the difference in climate between Alabama and Wisconsin. He is a graduate of Iowa State University with a degree in meteorology. Like any meteorologist, John is intrigued by extremes of weather, especially arctic air outbreaks and winter storms. John has been known to say he prefers his summers to be hot but in winter, he prefers the cold. When away from work, John enjoys long-distance running and reading. John has been a meteorologist at WDAY since May of 1985.
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The question of whether or not a storm or any other kind of weather has been made worse by global warming is really missing the point. Global warming is about climate whereas any particular weather event (storm, hot day, etc.) is weather, and the two are actually different. Globally averaged, the air has warmed. But the daily ups and downs of weather still happen. Although the Atlantic Basin is having a rough hurricane season, there is nothing about any of these storms that would have been impossible 100 years ago.
(WDAY/WDAZ TV) Severe thunderstorms are likely this Tuesday evening and night across the eastern Dakotas and western Minnesota. A strong upper level low pressure area approaching from the Pacific Northwest is causing strong southwesterly winds in the upper levels of the atmosphere. At the surface, muggy conditions and a strong southeast wind is undercutting this upper flow, creating an explosive storm situation. The moist air will be forced upward and the wind structure will create an environment in which strong, rotating storm updrafts are likely.
The appearance of autumn colors in trees is not caused by cool temperatures or frost, as many people believe. Rather, leaves turning red and yellow is mainly a function of the growing hours of darkness.
Hurricanes are rated on the Saffir-Simpson scale. Like an old model car, it is relatively well understood and easy to use. But it lacks efficiency and modern conveniences. Saffir-Simpson assigns a category, 1-5, based on a combination of maximum wind speed and minimum air pressure. Actual hurricanes, however, have other characteristics that this simple rating scale fails to account for.
Statistics are often misused and misunderstood. Climatologists occasionally refer to a particular storm or flood as a 100-year or 500-year storm. Hydrologists occasionally make reference to a 100-year or 500-year floodplain. These references are too frequently misunderstood to mean a one-in-100-year or a one-in-500-year event, implying that such a thing will happen that infrequently. Not so. At face value, a 100-year event has a 1 percent chance of happening in any year and not just once in 100 years.
Here in the landlocked heartland, we think of the ocean as being flat with waves, but this is frequently not the case. The storm surge that crept up the southeast coast from Florida to South Carolina is an example of a very damaging bulge in the level of the sea. Although the National Hurricane Center had issued numerous statements about unpredictable storm surges, many areas were unprepared for the height of the water. Harbors and river mouths, such as the ones in Miami and Jacksonville, Florida, and Charleston, South Carolina, experienced particularly bad flooding.
One particularly astute observer recently asked why the sunrise and sunset times he could find on the internet were not very precise and only to the nearest minute. Because a solar eclipse can be predicted to the minute centuries in advance, why couldn't he get a sunrise time down to the second? This is a very good question. First of all, we have to establish a horizon. A person watching the sunrise from behind a hill will see the sun's disk much later than a person in flat country.
Air temperature is officially measured in the shade at a height of 2 meters, or about 6 feet, above ground. A standard thermometer cannot measure the temperature in the sun because the thermometer bulb is heated more than the air and gives too hot a reading. Other surfaces may have temperatures distinctly different than the air. (Think about touching a metal car hood in the summer sun or bare handing a metal pole in winter.)
One particularly noticeable feature of the change of the seasons this time of year is the sharp reduction in daylight. Back in late June, at the time of the summer solstice, our days were almost 16 hours long. All summer the days have been getting shorter, but not at a particularly noticeable rate. By the last day of August, we still had 13 hours and 24 minutes of sunlight.
Over the past couple of decades, there has been an interesting, seemingly divergent pattern with hurricanes around the world. There are fewer of them, but there are more really intense ones. It is not known whether this trend is related to greenhouse warming (global climate change) as there are conflicting studies throughout the scientific literature.